ITU-T Newslog - Access

Carrier network standards approved at Geneva meeting

Sat, 17 Dec 2011 05:56:52 GMT

Key standards (ITU-T Recommendations) on a technology (MPLS-TP) required by telecoms operators to increase network efficiency while also reducing capex and opex costs have been approved (or attained first level approval) at a recent ITU meeting.

MPLS-TP refers to extensions to the IETF's MPLS protocol developed in cooperation with the IETF. MPLS can carry packets of different types, allowing telecom operators to offer private connections as well as IP services. Many network operators expect MPLS-TP to work under the same principles as longstanding ITU transport network technologies like SDH and OTN. MPLS-TP provides network operators with a reliable packet-based technology the operation of which aligns with current organizational processes and large-scale work procedures. Its deployment may reduce the need for layer 3 routing in an operators network.

Another important draft standard in the field has been forwarded to ITUs quadrennial World Telecommunication Standardization Assembly (WTSA-12) in Dubai next year. This provides an Ethernet based protocol for operations, administration and management (OAM) for Transport MPLS (MPLS-TP). The delay in approval follows the breakdown of a deal brokered by the Japanese administration in November. The compromise proposed was intended to address concerns expressed by IETF, following a series of previous setbacks, detailed here and here. Unfortunately the IETF were unable to deliver one key element of the proposal, the ACh codepoint which contributed to four national delegations vetoing the standard.

Malcolm Johnson, Director, Telecommunication Standardization Bureau, ITU: I would like to thank Japan for its great effort as a neutral party to find a compromise that took into account IETFs concerns. It is clear that the majority of the worlds ICT industry and governments supports this standard. It is a practical solution demanded by operators around the globe. I am hopeful that IETF will be able to assign the ACh codepoint before WTSA-12 which should allow the standard to be approved by consensus. ITU has a tradition of working by consensus but this is dependent on delegations being willing to compromise.

At the close of its December meeting Study Group 15 repeated its request to the IETF to provide an ACh codepoint for the Ethernet based OAM protocols. This request is in line with ITUs continued commitment to a collegial working environment for ICT standards development.

Statement ahead of IETF meeting

Mon, 14 Nov 2011 08:24:09 GMT

Ahead of IETFs 82nd meeting Malcolm Johnson, Director of ITUs Telecommunication Standardization Bureau (TSB) has issued a statement underlining ITUs commitment to a collegial working environment for ICT standards.

"Wherever appropriate, ITU will continue to reference the deliverables of other standards bodies rather than duplicating their work, and as far as possible we try to avoid the development of competing standards. By doing so we can best serve the needs of the international ICT community."

The statement underlines ITU core principles on cooperation detailed in ITU-Ts strategic plan (contained in Resolution 71 (Rev. Guadalajara 2010)) : Cooperation and collaboration with other standardization bodies and relevant consortia and fora are key to avoiding duplication of work and achieving efficient use of resources, as well as incorporating expertise from outside ITU.

Full details on generic procedures for including references to documents of other organizations in ITU-T Recommendations can be found in ITU-T Recommendation A.5.

Consequently Mr Johnson and Mr Russ Housley, Chair of the Internet Engineering Task Force (IETF) have agreed that MPLS, including MPLS-TP, is defined exclusively in the standards-track RFCs. The ITU-T will reference the IETF RFCs for MPLS-TP from its Recommendations providing there is consensus that they meet the needs of its members. By mutual agreement some other specific aspects, including the equipment model and protocol-neutral management information model (G.8121-series, G.8151, G.8152), developed in ITU-T are considered part of MPLS-TP.

Increasing standards participation in the CIS region

Mon, 12 Sep 2011 12:45:08 GMT

ITU is organizing a Regional Workshop on Bridging the Standardization Gap for the CIS Region on 7th October in Chisinau, Moldova back to back with the ITU Cross Regional Seminar on Broadband. The workshop and is being organized by ITU in cooperation with the Ministry of Information Technology and Communications of the Republic of Moldova.

Taking part in the standardization process for new technologies will accelerate the deployment of new networks and services bringing connectivity to cities and towns as well as remote areas. With next generation broadband technologies for example, standards work is lowering the capital cost of deployment in the network core. The main objective of this workshop is to examine key standardization activities on emerging technologies and actions that countries can take to bridge the standardization gap. Participation in standardization activities offers the opportunity for developing countries to jump several generations of technology. ITU will take into account the needs of these countries in producing its standards, and will seek to provide assistance in implementing them.

ICT industry backs greenhouse gas emissions methodology - Green standards take centre stage at Rome event

Mon, 12 Sep 2011 09:27:36 GMT

The first ITU Green Standards Week closed Friday with a call on international bodies, NGOs, standards bodies, governments, regulators, industry and academia to collaborate more closely on the application and development of information and communication technologies (ICT) standards to help combat climate change. Particular emphasis was placed on a globalized methodology to assess the environmental impact of ICTs, reducing e-waste, and the use of submarine cables for climate monitoring and disaster warning.

ITU has been working with industry and government members aiming to achieve agreement on an internationally recognized set of methodologies to be approved by the end of the year. Included is a methodology which ICT companies can use to measure their own carbon footprint, as well as a way to estimate the considerable savings in global greenhouse gas (GHG) emissions and energy that can be achieved in other sectors through the use of ICTs.

Full press release

Webinars to focus on optical fibres and networks

Tue, 30 Aug 2011 15:36:54 GMT

ITU-T is to host two webinars in September kick starting a new programme of standalone virtual events that will augment the traditional workshops programme.

The first event on 15 September will focus on Optical fibres, cables and systems and is based on the ITU-T handbook of the same name. The webinar will provide a basic overview of the handbook which offers a functional grouping of ITU standards (ITU-T Recommendations) on optical technology e.g. optical fibres and cables, physical optical interfaces, optical fibres terrestrial and submarine cable systems.

Speakers are leading experts in the field from industry and either participated in the writing of the handbook or contributed to the development of the referenced standards. The event is aimed at engineers, technicians, technologists, mid-level management and regulators active in the implementation of optical-fibres-based systems. The online event complements the 2nd ITU Tutorial on Optical Fibres Cables and Systems which will take place at the National Polytechnic Institute in Mexico City, Mexico from 19 to 30 September 2011.

Find out more here: http://www.itu.int/ITU-T/worksem/optical-fibre/201109/webinar.html

The second event on 20 September focuses on ITU-T standards for optical transport networks (OTN) which have played a leading role in transforming the Internets bandwidth capabilities. This work is led by ITU-T Study Group 15, which has developed a set of standards (ITU-T Recommendations) that define the existing OTN framework. SG 15 is currently developing future technologies such as gigabit-capable and 10-gigabit-capable passive optical networks (GPON and XGPON) to satisfy the unprecedented bandwidth requirements that will soon be demanded by service providers and consumers. This online event is based on the ITU-T manual on Optical Transport Networks from TDM to Packet.

Find out more here: http://www.itu.int/ITU-T/worksem/otn/201109/index.html

Tutorial on optical fibre and systems: Mexico

Fri, 22 Jul 2011 07:41:36 GMT

The 2nd ITU Tutorial on Optical Fibre Cables and Systems will take place at the National Polytechnic Institute in Mexico City, Mexico from 19 to 30 September 2011.

The tutorial is based on the ITU-T handbook Optical fibres, cables and systems which offers a functional grouping of ITU standards (ITU-T Recommendations) on optical technology e.g. optical fibres and cables, physical optical interfaces, optical fibre terrestrial and submarine cable systems. The tutors are leading experts in the field from industry and either participated in the writing of the handbook or contributed to the development of the referenced standards. The event is aimed at engineers, technicians, technologists, mid-level management and regulators active in the implementation of optical-fibre-based systems.

The programme will provide an in-depth insight into the ITU-T Recommendations that have shaped the optical transport networks of the world. Some aspects of wireless communication will also be addressed in cooperation with the Development Sector of the ITU (ITU-D). Participants will gain a insight into how to design and implement projects choosing the most appropriate state-of-the-art equipment. In addition they will learn how to evaluate a power budget and the fundamental parameters to be taken into account in the preparation of technical and administrative specifications for a supply contract.

On Saturday, 24th September, a crash course on Optical fibres, cables and systems will also be held at the same venue. The target audience will be university students and/or specialized schools from Mexico and other Latin American countries. It is intended to provide participants a general overview of optical fibre standardization. In addition a supporting webinar will take place in the week starting 12 September details to follow.

Conformity assessment highlighted in Fiji meeting

Fri, 08 Jul 2011 07:54:55 GMT

The ITU Regional Workshop on Bridging the Standardization Gap (BSG) for Asia Pacific Region closed 5 July 2011 with agreement on the need for adaptable and scalable solutions to address common issues faced by island states in the Pacific. These include conformity assessment and certification; spectrum management best practice for mobile broadband and digital broadcasting, and national spectrum allocation tables and harmonized spectrum use; public protection and disaster relief systems.

In addition delegates agreed on the need for assessment of ICT standardization benefits and ways to prioritize involvement in global standards development activities. To this end a national/regional ICT standardization strategy and roadmap based on conceptual tools such as the standardization development ladder will be adapted for Pacific Island requirements and also applied to the radiocommunication spectrum and standards environment. Also under consideration is a capacity building programme for developing countries in the region focusing on implementation of standards for broadband, wireless and NGN targeting ICT regulatory authorities and operators

The overarching goal of ITUs Bridging the Standardization Gap program is to facilitate increased participation of developing countries in standardization, to ensure that developing countries experience the economic benefits of associated technological development, and to better reflect the requirements and interests of developing countries in the standards-development process. One specific objective of this project is to understand the primary gaps that must be overcome to improve the standards development, implementation, and usage capacities of developing countries.

A number of measures have already been implemented by ITU to facilitate the participation of developing countries in ITU-T study group meetings. For instance, almost all ITU-T study groups are now using remote participation as part of their regular working methods. The number of Study Group leadership positions during the Study Period 2009-2012 has increased to four Chairmen and 47 Vice Chairmen from developing countries, including five Vice Chairs from least developed countries. In 2010, for the first time, participants from developing countries outnumbered participants from developed countries in study group meetings participation.

The workshop was organized in association with Pacific Islands Telecommunications Association (PITA) and the Telecommunications Technology Association (TTA) of the Republic of Korea with the generous support of the Korea Communications Commission (KCC), Republic of Korea.

The Optical World

Mon, 20 Jun 2011 07:44:19 GMT

A new ITU-T Technology Watch Report provides an overview of emerging trends in optical networking and progression towards the all optical computer. The report also surveys current and forthcoming standardization work in the field of optical technologies.

Today, the most widely used optical technology is optical fibre for high-speed interconnections, such as in server racks, connecting offices, buildings, metropolitan networks, in computers for data transfer and even continents via submarine cables. However, none of these devices is fully optical; all rely to some extent on conventional electronic circuits and components.

In the past, high costs have prevented optical components from finding their way into computers. But as optical technology matures, prices drop and the limits of miniaturization appear to have been reached, optical alternatives are finding their place in computer systems. The use of all types of optical technologies in communication networks and computers, because they consume less power, is seen as a major saving on operational costs for service providers, while at the same time helping to reduce the carbon footprint. The gradual incorporation of optical technology into the world of traditional electronics is paving the way for the era of the optical world.

Without optical technologies and optical networking related standards, the Internet as we know it today would not be feasible. Optical technologies have been the driving force behind the bandwidth growth of the Internet and enabled the emergence of bandwidth hungry applications for video and new business models such as YouTube which allows users to share video clips. According to the annual Cisco Visual Networking Index, the estimated global Internet Protocol (IP) traffic was 176 exabytes (x10¹⁸) in 2009 and is projected to increase more than fourfold to reach 767 exabytes by 2014. This growth will be driven mainly by video, due to improvements in bandwidth capacity and the increasing popularity of high-definition and 3D television.

ITU-T standards in optical transport networks (OTN) have played a leading role in transforming the Internets bandwidth capabilities. This work is led by ITU-T Study Group 15, which has developed a set of Recommendations that defines the existing OTN framework, and is currently developing future technologies such as gigabit-capable and 10-gigabit-capable passive optical networks (GPON and XGPON) to satisfy the unprecedented bandwidth requirements that will soon be demanded by service providers and consumers.

Major breakthroughs are expected in the areas of optical networking, silicon photonics, nanotechnologies and non-linear optics which could lead to major changes in the way computers, networks and data centres are designed.

A dedicated website provides additional sources of information and an overview of ITU-T Study Groups with work items related to optical technologies.

Download Report Go to Optical World Website

Multiple Silicon vendors demo market readiness for ITU home networking standard

Tue, 07 Jun 2011 07:13:38 GMT

Four ITU-T G.hn chipset manufacturers converged on Geneva this week to test interoperability between their products. The advanced interoperability demonstrated highlights the maturity of the various vendors' designs and the completeness of the G.hn standard. Experts expect products on the market before the end of the year.

Hosted by ITU, the event was a joint effort of HomeGrid Forum and the Broadband Forum, and the first major opportunity for silicon vendors to test the interoperability of their products for the G.hn home networking standard. The event was facilitated by the University of New Hampshire Interoperability Laboratory (UNH-IOL).

ITU-T G.hn is the first global home networking standard, created to unify home networking services and devices over any wire, including coaxial cable, phone lines or power lines. Lantiq, Marvell, Metanoia, and Sigma Designs participated in the week-long event that covered interoperation in the physical layer.

In parallel, experts met at a workshop designed to ensure that the electromagnetic compatibility (EMC) concerns are taken into account in the rollout of the new technology.

Interoperability is key to the success of any new technology, said Malcolm Johnson, Director of the Telecommunication Standardization Bureau. These events give vendors a unique opportunity to prove to service providers that their products are ready for market. And products conforming to the G.hn specification comply with the most rigorous EMC requirements that ensure they cause no interference to radio services.

HomeGrid is poised to launch a formal Compliance and Interoperability program, bringing HomeGrid certified products to the market this year and giving the industry a new benchmark of technology excellence for wired home networking. Another interoperability event is planned later in the year.

Interop event to test home networking spec

Tue, 17 May 2011 08:18:45 GMT

ITU will host an event to test the interoperability of products incorporating its ITU-T G.hn home networking standard, 23-27 May.

Facilitated by the University of New Hampshire Interoperability Laboratory (UNH-IOL), an independent provider of broad-based testing and standards conformance services for the networking industry, the event is a joint effort by the HomeGrid Forum and the Broadband Forum.

Members of the Broadband Forum and HomeGrid Forum will be able to submit their chipsets for interoperability testing with other chipsets. Results will further strengthen the test suite and will serve as the proving ground for future events and certification efforts. The intent is to provide a structured approach to multi-vendor interoperability testing.

ITU-T G.hn is the first global home networking standard, created to unify home networking services and devices over any wire, including coaxial cable, phone lines or power lines. The event is driven by vendor interest and the industrys desire to test early silicon and demonstrate G.hn technologys market potential. Multiple G.hn chipset vendors are expected to participate.

Specifically, the goals of this first G.hn Interop event are to launch the organizations formal test program, validate what is being defined in the test suite, and perform early tests for interoperability and compliance of chipsets from a number of vendors. Performance results will be recorded providing valuable feedback to the participating players prior to market entry. This allows for efficient editing to the test plans and helps ensure that products hitting the market are interoperable.

HomeGrid Forum will also hold additional events, in addition to its Compliance & Interoperability Program public interoperability events, compliance/conformance testing, and will eventually issue certification.

ITU expert speaks on MPLS-TP

Thu, 07 Apr 2011 07:27:47 GMT

ITU expert Huub Van Helvoort will speak at the Light Reading Ethernet Europe event in London next week. Van Helvoort will take part in a panel discussion: Extending Connection-Oriented Ethernet End-to-End Using MPLS-TP.

The session will focus on how operators can enhance their metro Ethernet networks and optimize them for transport by deploying an end-to-end Carrier Ethernet network that incorporates the emerging Transport Profile of MPLS (MPLS-TP) which provides interworking with IP/MPLS and packet-optical technologies. ITU recently agreed first stage approval of a key standard in the field here.

MPLS-TP promises to change the economic equation and enable more affordable end-to-end MPLS deployments by helping streamline operational models and consolidate/simplify network topologies.
The session will be moderated by Stan Hubbard, Senior Analyst, Heavy Reading.

MPLS-TP: The facts

Mon, 14 Mar 2011 09:43:24 GMT

With ITUs recent announcement on an OAM standard for MPLS in transport networks generating claims from the Internet Society that it will jeopardize the Internet, counter claims and much press coverage it seems the right time to set the record straight.

The technology at the heart of the debate is operations and management (OAM) for Transport MPLS. MPLS-TP refers to an adaptation of the Internet Engineering Task Force (IETF)'s MPLS protocol for telecom networks. MPLS can carry packets of different types, allowing telecom operators to offer private connections as well as IP services.

ITU-T Study Group 15 working on MPLS-TP voted 25, February 2011, to proceed with its own OAM solution, rather than only working with the IETF on the development its preferred OAM solution. This step was taken since, despite the agreement between the two organizations to work together, the OAM solution being developed by the IETF does not satisfy the requirements of some members of the ITU.

The text below charts a history of the work T-MPLS/MPLS-TP work in ITU to address a management protocol for telecom-operator networks and seeks to explain the divergence.

History of MPLS-TP

In 2006/2007 the ITU-T developed Recommendations on T-MPLS, a sub-set of MPLS that was targeted specifically for application in the transport network (to offer a more flexible interconnection between routers than SDH or OTN). By January 2008 the ITU-T had 5 approved Recommendation on T-MPLS and one on OAM ready for approval. However, in late 2007 the IETF indicated that T-MPLS may be in conflict with IP/MPLS. The ITU suspended work on T-MPLS and in 2008 agreed to work in cooperation with the IETF on the evolution of MPLS to meet the needs of the transport network. It was anticipated that the five existing Recommendations on MPLS-TP would be replaced by mid 2009 with a Recommendation on OAM following within a year. The IETF RFCs that are necessary to allow replacement of this initial set of Recommendations are not yet available.

One particularly contentious issue has been OAM. A significant segment of the operator community views that the IETF has given insufficient consideration to their needs, concerns, and proposals (documented in Internet drafts). The IETF state that the protocols currently under development will meet the requirements. After over a year of discussion, there has been no quantitative analysis to demonstrate that they satisfy the operational behaviour and procedures utilized in transport networks of these network operators.

One important initial step in the joint work was for the IETF and ITU-T agree on a mechanism to detect OAM packets that conforms to the MPLS architecture. The agreed mechanism uses a new reserved label (13) and a Protocol Identifier know as the G-ACh code point to identify specific functions and protocols. More than 64,000 of these code points are available.

The ITU proposed that the OAM for MPLS-TP should be based on Y.1731 (carrier grade Ethernet) which had already been proven to meet the requirements of the transport network. Instead in July 2009 the IETF insisted that the OAM should be based on existing IETF tools to support backwards compatibility. This included developing extensions to an existing tool, Bidirectional Forwarding Detection (BFD) for continuity check and connectivity verification (CC/CV).

In October 2009 the IETF disbanded the MPLS interop design team (the MEAD team) claiming that its work had been completed. The MEAD team was established in response to one of the proposals in the JWT report. See below for the relevant text from the JWT report.

Another proposal in the JWT report is that experts from the ITU should directly participate in the work of the IETF. However, since this group of experts are viewed as newcomers when considering rough consensus the opinions of these experts are given less weight than the opinions of long term IETF participants. This is allowed by the IETF guidelines when judging what it calls rough consensus. However, it does not meet the intent of the collaboration between the ITU and the IETF. Since the MEAD team was disbanded the IETF has continued to take decisions on the direction of the work without consulting the ITU, without informing the ITU of these decisions, or requesting confirmation from ITU that the resultant solutions produced by the IETF will meet the needs of all of the membership of the ITU. Several RFCs on MPLS-TP have been approved without receiving consensus support from the ITU.

In May 2010 the MPLS working group adopted the BFD based draft by rough consensus. The WG chair suspended the poll for making this a WG draft since we are not reaching consensus (see http://www.ietf.org/mail-archive/web/mpls/current/msg04502.html), a few days later he decided to adopt the document as a WG draft anyway (see http://www.ietf.org/mail-archive/web/mpls/current/msg04512.html). In an attempt to meet some of the requirements of the transport network the BFD draft has evolved. It is no longer backwards compatible with the existing BFD based tools or with any of the existing PW OAM tools. It uses a complex state machine to negotiate the repetition rate of the messages. This state machine is only required to allow routers (that have been optimized for other applications) to negotiate a lower repetition rate for OAM messages since they are unable to sustain the rates required for transport network applications. One of the key requirements of the transport network is that the repetition rate must be set by the network operator and remain fixed at this value. Adding a state machine to negotiate the rate significantly increases the complexity and impacts the scalability of the network. For applications in the transport network, a solution that does not use rate negotiation is technically superior and less complex (and therefore offers a lower cost solution).

The IETF have continually refused to consider the Y.1731 based solution (in draft-bhh-mpls-tp-oam-y1731 and G.tpoam) despite the extensive deployment experience, successful multi vendor interoperability tests and strong support from multiple network operators.

The current approach is dissipating significant resources from both standards organizations without producing tangible results. It is unlikely that these views will be reconciled by further discussion (as shown by the discussions in SG15 meeting in February 2011).

In an attempt to break this deadlock, in July 2010 at the request of several Member States, the ITU-T proposed an enhancement to the model for the interaction with the IETF on OAM. This proposal was based on the model that was used with great success when the IEEE and ITU collaborated on the development of OAM for carrier grade Ethernet. This approach allows both organizations to develop solutions that meet the needs of their constituents within a common architecture and would significantly reduce the amount of time spent by both standards bodies. However, so far the IETF have chosen not to explore this approach.

Due to this lack of progress, and to meet the needs of its members, ITU-T decided to move ahead and document an OAM solution that can co-exist, both in the network and in the Recommendations, with an IETF defined solution. The solution being proposed by the ITU conforms to the MPLS-TP architecture as defined by the IETF. It uses an IETF defined mechanism (the allocation of a unique ACh code point) to ensure that it will not interfere with any IETF defined mechanisms. Further, in the case where networks that run the IETF defined solution must be interconnected with a network that runs the ITU solution, then the IETF solution must be used.

The prime objective at the start of the joint work was to ensure that the extensions required to make MPLS fit for use in a transport network are within the MPLS architecture. The proposals from the ITU conform to the MPLS architecture and complement (rather than contradicts) solutions under definition in IETF to meet the needs for the global industry (including those operators that are not satisfied with the IETF solution). It is the IETF who have chosen to characterize the ITU actions as breaking the agreement despite the fact that they have already ignored the proposals in the JWT report.

JWT report proposal on Future inter-SDO organizational structure (slide 5 of the JWT report):

The JWT report indicates that the inter-SDO structure is intended to support collaborative work:

It is proposed that the MPLS interop design team, JWT and ad hoc T-MPLS groups continue as described in SG15
   TD515/PLEN with the following roles:

         Facilitate the rapid exchange of information between the IETF and ITU-T
         Ensure that the work is progressing with a consistent set of priorities
         Identify gaps/inconsistencies in the solutions under development
          Propose solutions for consideration by the appropriate WG/Question
         Provide guidance when work on a topic is stalled or technical decision must be mediated

The work of these inter-SDO groups was not completed when the MEAD team was disbanded as the ongoing debate on the OAM solution demonstrates. The IETF did not consult the ITU or even inform the ITU on several critical decisions, for example. The unilateral decision by the IETF to adopt the BFD draft as the solution for CC/CV; the refusal to consider draft-bhh-mpls-tp-oam-y1731; to consider the input from the ITU that two solutions should be standardized; all of these decisions were taken by rough consensus over strong objections. This is clearly contrary to the collaborative mode of operation described in the JWT report.

History of MPLS OAM:

Y.1711 defined the first OAM tools for MPLS, this made use of a reserved label (14) as defined in RFC3429: Assignment of the 'OAM Alert Label' for Multiprotocol Label Switching Architecture (MPLS) Operation and Maintenance (OAM) Functions. That was published by the IETF in November 2002 as an Informational RFC.

Subsequently the IETF developed some alternative OAM tools for MPLS LSP, they also developed several different tools for use in PWs.
     It should be noted that in these cases the IETF did not declare that this multiplicity of OAM tools is harmful to the integrity of the Internet.

In 2007 the ITU developed draft Recommendation G.8114 documenting OAM tools for T-MPLS, this toolset was backwards compatible with Y.1711. This draft Recommendation was ready for approval in January 2008 G.8114. However, the IETF stated that the method used to detect the OAM packets violated the MPLS architecture and claimed that it would be harmful to the Internet. On the basis of these statements the ITU did not approved G.8114 and agreed to work in cooperation with the IETF to develop a solution that conformed to the MPLS architecture.

Note: More than 40,000 nodes running draft G.8114 OAM have been deployed without any reports of harm to the Internet.

After waiting three years for the IETF to deliver a solution that will meet the needs of its membership SG15 has now voted in favour of solution which conforms to the MPLS architecture and meets the needs of its membership.

Despite all this effort on the part of ITU to collaborate with IETF it is now falsely claiming that ITU reneged on the JWT agreement.

Comparison of MPLS-TP OAM and Ethernet OAM

The figure below illustrates the OAM frame formats for Ethernet and MPLS-TP

In the case of Ethernet the IEEE and ITU mutually agree on the assignment of the OAM OpCode values to differentiate between OAM PDUs defined by the ITU and IEEE. This allows the ITU-T to develop OAM functions targeted at the transport network without any possibility of a clash with IEEE developed protocols.

The Channel Type could offer the same degree of separation if the IETF assigned a channel type for use by the ITU-T for OAM targeted for application in transport networks.

ITU satisfies market demand for carrier class MPLS standard - Network operators given cost-effective management solution

Mon, 28 Feb 2011 09:59:36 GMT

Geneva, 28 February 2011 In a big step towards leveraging existing MPLS (Multiprotocol Label Switching) deployment in transport networks, ITU has agreed first stage approval of a key new standard. The ITU-T standard will give network operators the tools necessary to manage large scale deployments of MPLS-based networks. Network operators will now have a choice of OAM (operations, administration and maintenance) tools to best meet their specific transport network requirements. These OAM tools in the hands of network operators will, in particular, allow quick detection of defects and fault isolation.

MPLS is widely embraced in backbone networks as a way to speed up routers. The OAM tools in the ITU-T standard are based on technology proven in carrier grade Ethernet services and legacy transport networks, making it easier for operators to upgrade. In addition to reducing labour costs, network operators will see significantly reduced capital expenditure (CAPEX) costs given that the standard allows for more efficient allocation of bandwidth.

Operators are increasingly looking to MPLS as an end-to-end technology, given its inherent flexibility and support for IP-based applications. The decision was taken together with first stage approval of another standard providing network architecture for MPLS-TP based networks.

Dr Hamadoun Touré, ITU Secretary-General, said: ITU collaborates and coordinates, in good faith and on the basis of reciprocity, with other relevant organizations in the development of IP networks to ensure maximum benefits to the global community. This is in accordance with the decisions of the 2010 ITU Plenipotentiary Conference. However, this should not lead to a situation where the ITU fails to deliver on its commitments to its own membership. Much effort was made to reach a compromise during last weeks Study Group 15 (SG15) meeting, but the decision was taken very exceptionally by vote, since all attempts at compromise had failed.

ITU-T SG15 began working on transport profiles for MPLS technology suitable for use in the network layer of transport networks more than three years ago. A joint working team (JWT) was set up to allow Internet Engineering Taskforce (IETF) and ITU experts to work together to avoid divergent work streams. Specifically, it was expected that this group would provide the necessary protocol extensions for ITUs specifications to work in an MPLS environment. IETF committed to provide its contribution by the second quarter of 2009. However this crucial technical input was not provided and the IETFs MPLS-TP Interoperability Design Team (MEAD) was unilaterally disbanded by IETF in October 2009.

Malcolm Johnson, Director, Telecommunication Standardization Bureau, ITU: ITU is a consensus based organization and voting is always a last resort. In this case it was clear that a significant part of our membership could not accept any further delay in pursuing a solution that will give them the ability to address a real market need. Given that there are over 100,000 MPLS-TP nodes already in transport networks, it is essential that the corresponding OAM tool.

The Future of Ethernet Transport

Thu, 06 May 2010 13:13:44 GMT

ITU-T and IEEE will hold a joint workshop - The Future of Ethernet Transport - in Geneva, 28 May 2010. The workshop is the fifth in partnership with IEEE and follows two Kaleidoscope events and two workshops in the field of access and transport technologies.

Much work has been done in both organisations to progress Ethernet, developed as an enterprise technology, into a network provider technology or service. The event will focus on opportunities for further collaboration. Long-recognized as the ubiquitous LAN technology, Ethernet is now seeing increased attention as a carrier-grade technology. In part this is due to the convenience of being able to simply provide end-to-end service, but also carriers can realize savings both in terms of capital and operational expenditure.

Ethernet services are becoming popular because they allow carriers to offer considerably improved flexibility to customers through a much simpler and lower cost interface. Ethernet allows users to specify exactly how much bandwidth they want between the 10Mbit/s and emerging 100Gbit/s range currently offered. Further, as a transport technology Ethernet provides reduced operation complexity and improved scalability for carriers. And as operators look to NGN and the use of the Internet Protocol (IP), Ethernet is seen as the best fit, especially given the rise of such services as IP VPNs, VLANs and dedicated Internet access.

This event will review the work areas within ITU-T and IEEE 802.1/802.3 Working Groups on the development of Ethernet and related transport standards. The relevant standards groups are ITU-T Study Group 15 (Questions 6, 9, 10, 11, 12, 13 and 14) on optical transport systems including protection switching and synchronization, and IEEE P802.1Qbf Task Force on protection switching, P802.1AS and P802.3bf Task Forces on Ethernet synchronization, and P802.3ba and P802.3bg Task Forces on 40/100 Gb/s Ethernet.

ITU-T and IEEE works work on Ethernet technology is complementary in areas such as such as ultra high speed transport, network architecture, services, operation and maintenance, protection switching and synchronization. In general ITU-T develops requirements from a network operators viewpoint as well as functional level specifications, while IEEE develops detailed design specifications to allow implementation.

G-PON interop demo: Las Vegas

Wed, 11 Jun 2008 07:26:37 GMT

NXTComm, June 16-19, Las Vegas, USA will see ITU-T members, and guests stage an interoperability showcase for fibre to the premises (FTTP) related standards.

ITU, together with Telcordia, have collaborated to organize a multi-company interoperability demonstration featuring gigabit passive optical network (G-PON) equipment built according to the ITU-T G.984 series of Recommendations (standards) , including the recently consented G-PON reach extender (ITU-T G.984.6). PON technology is used in the local loop environment to cost effectively connect residential and small and medium enterprises (SME) end users premises in an all-fibre network.

The G-PON Pavilion features live demonstrations of G-PON equipment interoperability; with interoperability being a critical enabler to reducing G-PON equipment costs. Triple-play interoperability demonstrations are provided by the following device and equipment manufactures: Cambridge Industries Group, Freescale Semiconductor, Iamba Network, Ikanos Communications, LS Cable, XAVi Technologies, ZTE Corporation. Corning is providing a bend-insensitive fibre (built to ITU-T G.657 specs) based optical distribution network over which the 2488 Mbps/1244 Mbps (downstream/upstream) G-PON systems will be operating.

With PONs, signals are carried by lasers and sent to their destination without the need for active electronics in the outside plant of the telecommunications network. Carriers can realize significant savings with fiber sharing in the local loop, equipment sharing in the central office and by eliminating the dependence on expensive active network elements.

ITU-Ts G.984series Recommendations detail gigabit PONs (G-PON), the latest generation of PON technology. With gigabit capacity today and the ability to transparently support future capacity upgrades through ITU-T G.984.5 compatible overlays, ITU-T G.984-based systems should more than satisfy foreseeable customer demands. G-PON (ITU-T G.984.6) reach extender solutions allow operation over as much as 60 km of fiber, with split ratios as high as 1x128.

ITU-T/IETF interoperability issues addressed

Mon, 21 Apr 2008 13:45:41 GMT

Fears that a set of next-generation network transport specifications developed by ITU-T could cause interoperability problems have been allayed.

The IETF and ITU will work together to extend IETF MPLS functionality to address the needs of the transport network. The work will move forward recognizing that the sole design authority for MPLS resides in the IETF, and the domain of expertise for Transport Network Infrastructure resides in ITU-T SG15.

ITU-T has been developing extensions to Internet Engineering Task Force (IETF) MPLS to address the requirements of the transport network (T-MPLS). However, concerns were raised by the IETF that the approach taken by the ITU-T was incompatible with widely deployed - MPLS - technology. These concerns have been allayed with the agreement that the IETF and ITU-T will work jointly on the development of a transport profile for MPLS technology which will now be referred to as MPLS-TP.

The Joint Working Team (see previous newslog entry) consisting of experts from the IETF and ITU-T has recommended that IETF MPLS technology should be extended to meet the requirements of the transport network. The proposal is based on technical analysis that showed that the IETF MPLS architecture can be extended to provide the functionality required by the transport network as defined by ITU-T's Study Group 15. The ITU-T has accepted this proposal and the IETF will develop a transport profile for MPLS (MPLS-TP) with input from ITU-T to ensure that the requirements of the transport network are fully addressed. Details of the proposal and the technical consideration are available here.

Malcolm Johnson, Director, ITU Telecommunication Standardization Bureau said, "Given the complexity of todays networks it is inevitable that we will, from time-to-time, see divergent approaches. What is important is that we quickly agree on a way forward. The experts in the joint group have worked hard to find a cooperative solution rather than going our separate ways. This is an excellent result and bodes well for the future collaboration between ITU and IETF".

Russ Housley Chair of the IETF, "I am very optimistic about the outcome, and I see this as a significant milestone in the cooperation between the ITU-T and the IETF."

Experts issue energy saving challenge

Fri, 22 Feb 2008 14:59:40 GMT

Senior technical experts have laid down the gauntlet on energy saving in ICTs following a recent meeting in Geneva.

Following tutorials on power saving, at a recent meeting of ITU-Ts Study Group 15 (SG 15), experts agreed to work towards a proposed percentage reduction of power consumption in broadband technologies. The aim is for the agreed figure to form part of a Resolution from the upcoming World Telecommunication Standardization Assembly (WTSA-08). Reduction of power consumption should and can be done without the degradation of services according to experts. Presentations from the tutorials are available here.

The UN Secretary-General, Ban Ki-moon has also underlined ITUs role here saying: "ITU is one of the very important stakeholders in the area of climate change." ITU representatives made a statement at the UN Conference on Climate Change in Bali, Indonesia, illustrating how ICTs are both a cause and a potential cure for climate change.

Speaking during the event attended by over 100 representatives from the ICT industry worldwide for each of its three, hour-long sessions, Deputy Secretary-General of ITU, Houlin Zhao expressed appreciation that the meetings had proven so popular at such an early stage of the work. He pointed out that ICTs are responsible for 2.5 per cent of carbon emissions. This is roughly the equivalent of the airline industry and requires our urgent attention, he said.

The issue of power saving will be discussed within the wider context of climate change at Symposia on ICTs and Climate Change, to be held April 15-16 2008 in Kyoto, Japan, hosted by the Ministry of Internal Affairs and Communications (MIC) and 17-18 June 2008 in London, hosted by BT. The events are part of a new initiative by ITU to better understand how ICTs can help mitigate and adapt to climate change as well as monitoring its impact.

Experts speaking at the SG 15 tutorials pointed to inefficiencies in terms of end-device power consumption level compared to the signal power. The deployment of broadband access networks is of particular concern as operators worldwide rollout this new technology that some predict will massively increase power demands.

Some simple measures, for example specifying power saving modes in network terminations such as: asleep, standby, as well as on and off, were cited by speakers. It was also noted that next-generation networks (NGN) can lower greenhouse gas emissions by reducing network complexity, and introducing equipment that is more tolerant to natural climatic conditions and therefore does not require air conditioning. Smart buildings, energy supply and transport industries must all play their part in achieving greenhouse gas reductions.

A first and completed task of the ITU experts has been to create a power saving checklist for standards authors. Malcolm Johnson, Director of the Telecommunication Standardization Bureau, ITU congratulated SG 15 for responding so quickly to the request to address climate change. He urged all Study Groups to start the process of reviewing their Recommendations (ITUs name for standards) according to the new checklist and assign appropriate metrics regarding reduction of greenhouse gases.

The checklist is intended to ensure that standards are drafted taking into account the most economic and energy-efficient solution. It is essentially, a set of questions relating to energy saving in networks. Experts propose that each new ITU-T Recommendation should contain a clause that identifies its impact on climate change and demonstrates ways that it contributes towards emission reduction, covering both production and the use of the equipment.

In order that this work is completed with the highest degree of efficiency there is broad consensus that ITU action has to be taken in partnership with all other bodies working in the field and that everything is done to avoid duplication of work.

Final Call for Interest: ITU G-PON (G.984) Pavilion at the NXTcomm 2008 (Las Vegas, USA, 16-19 June, 2008)

Fri, 08 Feb 2008 08:38:22 GMT

ITU, together with Telcordia, are again collaborating to organize a multi-company interoperability demonstration featuring gigabit passive optical network (G-PON) equipment built according to the ITU-T G.984 Recommendation. Participating companies are now being finalized, with interested companies being requested to contact Rob Bond (rbond@telcordia.com), G-PON Pavilion Coordinator, by Monday February 25, 2008. Any optical access system, customer premises equipment, or G-PON device vendor with commercial products compliant with G.984 series Recommendations are eligible to participate.

The interoperability demonstration featured in the ITU G-PON (G.984) Pavilion at NXTcomm 2008 may include both traditional FTTP-focused G-PON technology, as well as emerging applications such as G-PON fed xDSL services, Enhancement band operation (G.984.5), and G-PON Reach Extender demonstrations (G.984.re). More information is contained in the ITU G-PON Pavilion fact sheet.

DSL and PON: Energy saving techniques

Fri, 01 Feb 2008 08:27:47 GMT

In the context of ITU-T's efforts to address climate change issues, Study Group 15 will hold three tutorials on energy saving techniques during its February meeting.

A checklist for developers of standards is already under development in SG 15. The technologies considered in the list include optical transport networks and access network transport technologies such as digital subscriber line (DSL) and Gigabit-capable Passive Optical Networks (GPON). Together these technologies represent a significant consumption of energy worldwide. The idea is that the checklist is applied before the work commences, during the work and after the completion of the work. The use of the checklist should ideally be complemented by involving energy efficiency experts and users in the process.

The tutorials to be held 13, 14 and 15 February will look at the checklist as well as topics such as energy efficient Ethernet and opportunities and techniques for power saving in DSL and PON. A general introduction to the issues surrounding ICTs and climate change, (to be addressed in two upcoming ITU Symposia on ICTs and Climate Change), and an update on the outcome of the UN Climate Change Conference in Bali, December 2007, will be included.

2007: A year in review

Mon, 17 Dec 2007 15:38:32 GMT

Click here for a document detailing some ITU-T highlights for 2007.

Being there without going there with Telepresence

Mon, 19 Nov 2007 10:23:00 GMT

Do you remember your last video conference? Blurry faces on tiny screens, with sound that doesnt quite synchronize with the stilted movement of the lips. After the laborious setup of cameras and microphones, you seem to spend more time worrying about technical problems than talking about the topic at hand, with repeated loss of connection. As frustration grows, and attention wanders, it is difficult to avoid the feeling that you should have arranged a face-to-face meeting instead.

A new set of technologies referred to as Telepresence will give users the illusion of sitting on the opposite side of the remote partys conference table. High-definition (HD) video images and audio are transmitted via packed-based Next-Generation Networks (NGN), connecting conference rooms around the world, and covering distances of thousands of miles with zero latency. While the network infrastructure remains transparent to the user, vendors equip conference rooms with high-end displays, cameras, loudspeakers and furniture to enhance the conferencing experience. Telepresence-systems are already available on the market, and involved companies go as far as identifying the technology as a potential billion dollar market, for solution vendors as well as for network service providers (NSP).

A new ITU-T Briefing Report on Telepresence has been released as part of the Technology Watch function, which evaluates the market potential and different fields of application of Telepresence solutions in both, developed and developing countries. The report notes the standardization work currently going on in ITU, including the consideration of migrating currently used multimedia protocols, such as H.323 and SIP into a new generation of multimedia protocols, called H.325 or Advanced Multimedia Systems (AMS), that takes into consideration special aspects of security, flexibility, QoS, and support for mobile devices. This report is the second of a new series of Technology Watch Briefing Reports looking at emerging new technologies.

T-MPLS agreement: ITU-T and IETF

Tue, 16 Oct 2007 08:53:28 GMT

Experts from the standardization sector of ITU (ITU-T) and the Internet Engineering Task Force (IETF) have agreed to recommend progression of Transport-MPLS (T-MPLS) standards work in a way that ensures compatibility, consistency, and coherence of MPLS technology when used in transport networks. The recommended approach, which recognizes and leverages ITU-T and IETF design expertise and authority, is expected to resolve concerns raised regarding usage of common Ethertypes for IETF MPLS and T-MPLS when running over an Ethernet backbone. Broader review and approval of the proposal by the two standards bodies is expected in the coming months.

The experts proposed in a joint statement that "The IETF and ITU-T will work in close collaboration on T-MPLS" and that "a joint working team of experts from the IETF and ITU-T be established to propose how to progress the various aspects of the requirements, solutions, and architecture for the T-MPLS work." The initial goal of the working team will be to examine T-MPLS work, and foster "an agreement on leadership roles and the modifications necessary to develop an architecture that it is compatible, coherent and consistent between both transport and IETF MPLS technologies."

Yoichi Maeda, Chairman of ITU-T's Study Group 15, home of the T-MPLS work said: "This type of agreement is a characteristic of the spirit of cooperation that exists between ITU-T and IETF. Both organizations understand that in order to meet the needs of industry it's imperative to quickly resolve differences and avoid duplication of work."

"Future work," the proposal states, "will be progressed by first analyzing the requirements and desired functionality." Since T-MPLS utilizes MPLS functionality extensively, the experts recommend that, "The IETF Standards Process will be used for extensions or modifications of IETF MPLS Technology." It was clearly noted that there are aspects of the problem space that lie outside the domain of expertise in the IETF or straddle both organizations, e.g., management of transport equipment, and some aspects of OAM and survivability. The working team will be tasked to help identify which of these aspects are best standardized in IETF RFCs and which in ITU-T Recommendations.

T-MPLS has been under development for three years in ITU-T with four specifications published, including an architecture document, a network-to-network interface (NNI), an equipment specification and a protection switching document. T-MPLS draws extensively on IETF MPLS, a foundation of more than 50 RFCs published by the IETF MPLS and PWE3 Working Groups over the last eight years.

ITU speaker at Dallas event

Tue, 25 Sep 2007 15:59:20 GMT

Optical Expo is a Light Reading event 2-3 October in Dallas.

Under the session heading The Drive to 100-GigE, Steve Trowbridge, Vice Chairman of ITU-T Study Group 15, will provide the latest updates on ITU standardization efforts as the industry moves to 40 Gbit/s and ultimately 100-GigE.

Global Carriers Demo ITU-T Standards Interoperability

Wed, 05 Sep 2007 07:39:59 GMT

The Optical Internetworking Forum (OIF) will host the results of an interoperability demonstration at ECOC 2007, Berlin, Germany. The event will show how a suite of ITU-T standards enable on-demand Ethernet services.

Seven global telecommunication carriers taking part will provide test facilities, engineering staff and network connectivity.

The demonstration will highlight dynamic Ethernet services over multiple, control plane-enabled intelligent optical core networks, including:
- Ethernet Private Line service
- Non-disruptive bandwidth modification
- Graceful recovery from control plane or signaling network failures

See the OIFs press release.

Future proof G-PON

Tue, 10 Jul 2007 14:50:49 GMT

At the June 2007 meeting of ITU-T SG15, a Recommendation that helps to future proof gigabit capable passive optical networks (G-PON) was consented.

The Recommendation, G.984.5, defines wavelength ranges which are reserved for additional service signals to be overlaid via wavelength-division multiplexing (WDM) in future gigabit capable passive optical networks (G-PON). The Recommendation also specifies the wavelength blocking filters to be implemented in optical network terminations (ONT). These filters, together with the use of the specified wavelength ranges, will enable network operators to upgrade G-PON systems without a break in service to their customers.

Home networking progress in June

Tue, 10 Jul 2007 14:48:58 GMT

At the June 2007 meeting of ITU-T SG15, work continued on a draft new Recommendation to develop a single international standard for home networking transceivers using any metallic media in the home phoneline wiring, data cable (e.g. CAT5), coaxial cable or powerline wiring.

Household connectivity is growing rapidly with more and more electronic devices and networks within the home distributing and using digital information and media. In addition, remote control of lighting, heating, appliance-use and security systems attached to the home are making the "digital home" a reality.

International standards that enable interoperability and security in the field of home networking are seen as key to bringing value and versatility to consumers, making possible the use of diverse products, services and sources, and therefore accelerating market development.

Work in ITU-T is coordinated by the Joint Coordination Activity on Home Networking (JCA-HN). Topics covered across the 13 different Study Groups of ITU-T include digital rights management (DRM), phone-line networking (including co-ax), IPTV, interactive video, set top box architecture and cable modems.

The work on ITU-T Rec - G.hn - next generation home networking transceivers - has now attracted a critical mass of contributors/participants with nine companies submitting 20 contributions on various topics. It is anticipated that G.hn will be completed in 2008.

Also at the June 2007 meeting of ITU-T SG15, it was agreed to start work on a draft new Recommendation G.hnta on home network transport architecture. The Rec will give a generic architecture based on the NGN functional architecture described in Recommendation Y.2012 Next Generation Networks Frameworks and functional architecture models It will describe a platform for the development of future home network standards. The draft Recommendation G.hnta is complementary to draft Recommendation H.ghna currently under development by SG16.

Standard extends DWDM distance

Mon, 02 Jul 2007 07:36:16 GMT

A second standard in a new group of Recommendations from ITU-T's Study Group 15 extends the distance at which multi-vendor DWDM systems can be deployed from 80 to four or five hundred kilometres.

The first standard in the series gave network operators the ability to deploy multi-vendor dense wavelength division multiplexing (DWDM) systems in a metro environment. The new Recommendation extends this to cover regional environments by taking into account the use of optical amplifiers and their potential to create 'optical noise'.

WDM technology is used by the owners of optical fibres to maximise their capacity. The technology achieves this by simultaneously operating an optical fibre pair at more than one wavelength and uses optical amplification to increase transmission distances as well as optical add/drop multiplexers to increase the flexibility of the network. Since operators wish to maximize their cable plant investments and deploy increasingly bandwidth hungry services in a multi-vendor environment, standards development in this field is seen as crucial.

The Recommendation defines values for single-channel optical interface parameters of physical point-to-point and ring DWDM applications on single-mode optical fibres through the use of the "black-link" approach. The black-links covered by this follow-on Recommendation may contain optical amplifiers.

The transport network of most operators is based on the use of equipment from a variety of different vendors. Previously, for those parts of the network involving DWDM optical transmission, this has been achieved via the use of optical transponders which convert the single channel interfaces like those defined in ITU-T Recs G.957 G.691, G.693, G.959.1 into DWDM wavelengths suitable for the particular vendors proprietary system. With the optical interfaces standardized in new G.698.2 operators can directly connect a wide variety of equipment to the DWDM line system without the need for those additional short reach transmitter and receiver pair per channel (eliminating the transponders) with obvious associated cost savings.

New standard means reduced operating costs

Mon, 18 Jun 2007 08:14:28 GMT

Another step towards all optical networks (AON) has been achieved with the consent of the new Recommendation G.680 by ITU-T's Study Group 15.

The Recommendation will allow operators to take optical add/drop multiplexers (OADMs) and photonic cross-connects (PXCs) from different vendors and integrate them in to an all optical network without having to add expensive optical/electrical/optical conversion (O/E/Os).

This achievement is made possible as the Rec gives operators a way to evaluate the end-to-end quality of a signal where photonic cross-connects (PXC) and optical add/drop multiplexers (OADMs) are deployed. In addition, experts say that the evolution towards an AON could significantly reduce costs for operators by reducing the need for costly optical/electrical/electrical (O/E/O) conversion. As optical transport networks (OTN) evolve, the number of - expensive - O/E/O conversions within their boundaries is coming down.

The two main reasons for the reduction in the number of O/E/O conversions are that DWDM systems are becoming capable of carrying light signals for thousands of kilometers without electrical regeneration and that PXCs and OADMs are becoming available with the capacity, space requirements, power consumption, reliability and cost, suitable for their use in the telecommunication networks. With this evolution experts predict that AONs could extend to all potential routes of the backbone network of a medium size country - optical paths up to around 2,000 km.

The Recommendation defines a "degradation function" of optical network elements (ONEs) such as photonic cross connects (PXCs), optical add-drop multiplexers (OADMs), etc. making up an optical network. It enables the degradation of the signal quality in an all-optical network consisting of ONEs including DWDM line segments to be assessed.

Popular fibre spec upgraded

Mon, 18 Jun 2007 08:10:50 GMT

An upgrade to a widely used specification for fibre optic cables will allow the simpler deployment of Gigabit Ethernet (GbE) in FTTH applications up to 500 m link distance. The original Recommendation ITU-T Rec G.651 provided specifications for multimode fibre which is currently widely deployed for data communications, but not for telecoms.

The work was initiated given two observations; the cost disparity between telecom and data networks, where high speed GbE telecom equipment is often far more expensive than datacom equipment; and the economics of rolling out FTTH into multi-tenant (apartment) buildings where there is a high subscriber density. Ethernet is increasingly seen as an end-to-end technology.

Similar to recently published Rec G.657 on single mode fibre, Recommendation G.651.1 allows for increased cable flexibility. This increased flexibility in a fibre optic cable means that operators can follow tighter corners in buildings and can worry less if cables / fibres are laid with a sharp bend. This all makes installation work more engineer friendly leading also to less re-work. Moreover the closures for fibres can be half the size, important where space is at a premium especially in multi-tenant buildings.

G.651.1 retains many of the key characteristics of its well known predecessor. However manufacturing tolerances and transmission characteristics have been improved significantly. In addition, it has been harmonized fully with relevant IEC standards.

Outside plant group meets, agrees new standards

Tue, 29 May 2007 11:57:25 GMT

The group that looks at outside plant and related indoor installations in ITU-T, Study Group 6, met in Geneva during May. Five new standards (ITU-T Recommendations) will be published as a result. Delegates also looked into a possible restructuring of the group that can be presented to ITU-T's quadrennial World Telecommunication Standardization Assembly (WTSA) to take place in the last quarter of 2008.

In addition, the meeting saw the presentation of the first draft of a guide for developing countries on how to implement its standards. The guide, drawing on the work of the world's key experts in the field, will become an invaluable resource for service providers in developing and, in particular least developed countries. Completion of the first edition is expected for November this year.

As well as the traditional technical discussions within the working groups, a technical tutorial session was held on fibre to the home (FTTH) experiences in China, Spain, US, and Italy. Experts say that this is important for delegates to SG 6 given the fact that FTTH deployments will mean more sophisticated equipment needs to be provisioned outside the central office. A common observation was that the right solutions, in particular for the implementation of the optical fibre infrastructure, need to be cost effective not only in themselves, but in a global view, taking into account the entire product lifecycle, including installation and, above all, maintenance issues.

One new Recommendation reached the final stage of ITU-T approval. ITU-T's L-series Recommendations have long been a reference for owners of optical fibres. The new ITU-T Rec. L.66 gives maintenance criteria for in-service optical cable testing in the outside plant without disrupting normal network operation.

Two Recommendations achieving the first stage of approval - known as Consent - detail safety in high-power optical cables and protection of active electronics in outside plant. Also new in a series of Recommendations for the management of network elements in the outside plant is a document detailing the requirements for personal digital assistants (PDAs) as tools for inventory management. Finally, the Recommendation that defines the marking of optical cables used in shallow water , known as marinized terrestrial cables, has been brought up-to-date given the today's more widespread deployment of fibre.

FTTP demo at NXTComm

Fri, 18 May 2007 14:18:22 GMT

NXTComm, June 18-21, Chicago will see ITU-T members, and guests stage an interoperability showcase for fibre to the premises (FTTP) related standards.

ITU, together with Telcordia, have collaborated to organize a multi-company interoperability demonstration featuring gigabit passive optical network (G-PON) equipment built according to the ITU-T G.984 Recommendation. PON technology is used in the local loop environment to cost effectively connect residential and Small and medium enterprises (SME) end users premises in an all-fibre network.

The G-PON Pavilion features live demonstrations of G-PON equipment interoperability; with interoperability being a critical enabler to reducing G-PON equipment costs. Triple-play interoperability demonstrations are provided by the following device and equipment manufactures: Alphion, Cambridge Industries Group, Hitachi, Huawei, iamba Networks, LS Cable, PMC-Sierra, Tellabs, Terawave Communications, TXP Corporation, XAVi Technologies, ZTE Corporation. Corning is providing the optical distribution network components over which the 2488 Mbps/1244 Mbps (downstream/upstream) G-PON systems will be operating.

With PONs, signals are carried by lasers and sent to their destination without the need for active electronics in the outside plant of the telecommunications network. Carriers can realize significant savings with fiber sharing in the local loop, equipment sharing in the Central Office and by eliminating the dependence on expensive active network elements.

ITU-T Recommendations in the G.984 series detail gigabit PONs (G-PON), the latest generation of PON technology. Increasing capacity to gigabit levels should more than satisfy foreseeable customer demands, offering video applications, high-speed Internet access, multimedia and other high-bandwidth capabilities. G-PON maintains the same optical distribution network, wavelength plan and full-service network design principles of broadband PONs (B-PON) defined in ITU-T Rec G.983. As well as allowing for increased network capacity, the new standard offers more efficient IP and Ethernet handling.

ITU/IEEE Carrier class Ethernet event

Tue, 15 May 2007 13:05:49 GMT

Ethernet services are becoming popular because they allow carriers to offer considerably improved flexibility to customers through a much simpler and lower cost interface. Ethernet allows users to specify exactly how much bandwidth they want between the 10Mbit/s and 1Gbit/s range currently offered. Further, Ethernet provides reduced operation complexity and improved scalability for carriers. And as operators look to NGN and the use of the Internet Protocol (IP), Ethernet is seen as the best fit, especially given the rise of such services as IP VPNs, VLANs and dedicated Internet access.

The event will start with an overview of the standards work from ITU-T and IEEE and will then drill down into detail with sessions focusing on: Ethernet based and Ethernet capable access networks; Ethernet network transport; Ethernet Bridging architecture; Ethernet OAM and management; Ethernet QoS, timing and synchronization. A closing session will bring together reports from all of the session chairs in order to identify the direction of future work.

ITU speaker to present at IEEE Global Standards and Developing Economies Seminar

Mon, 02 Apr 2007 12:56:16 GMT

Reinhard Scholl, Deputy to the Director of the Telecommunication Standardization Bureau, ITU will speak at a seminar titled Global Standards and Developing Economies: Broadband Access and Infrastructure 9-10 May, Tunis, Tunisia.

The event hosted by the IEEE-Standards Association (SA) in collaboration with the Tunisian Ministry of Communication Technologies will bring together leaders from industry, government and international standards organizations to share their insights on how local entities can participate in and optimize global standards and best practices to help close the digital divide.

An in-depth introduction to international standards activities and highlighting of the scope of the IEEE and its relationships with ITU and other standards bodies will be given. Through interactive presentations, the seminar will provide an overview of the issues being faced by todays policy makers and industry leaders and provide real world examples of how standards are making a difference in emerging economies.

In addition to discussion of broadband access and infrastructure standards via presentations and case studies, challenges and opportunities for developing countries regarding intellectual property rights (IPR) and standardization will also be addressed. For further information see here, or call the IEEE-SA Corporate Standards Office at +1 732 562 5342; E-mail cag-conference@ieee.org.

Joint ITU-T/IEEE workshop on Carrier-class Ethernet

Mon, 05 Feb 2007 12:02:41 GMT

ITU and the IEEE will hold a workshop on carrier-class Ethernet, 31 May- 1 June.

Much work has been done in both organisations to progress Ethernet, developed as an enterprise technology, into a carrier service. The event will focus on opportunities for further collaboration.

Long-recognized as the ubiquitous LAN technology, Ethernet is now seeing increased attention as a carrier-grade service. In part this is due to the convenience of being able to simply provide end-to-end service, but also carriers can realize savings both in terms of capital and operational expenditure.

Ethernet services are becoming popular because they allow carriers to offer considerably improved flexibility to customers through a much simpler and lower cost interface. Ethernet allows users to specify exactly how much bandwidth they want between the 10Mbit/s and 1Gbit/s range currently offered. Further, Ethernet provides reduced operation complexity and improved scalability for carriers. And as operators look to NGN and the use of the Internet Protocol (IP), Ethernet is seen as the best fit, especially given the rise of such services as IP VPNs, VLANs and dedicated Internet access.

The event will start with an overview of the standards work from ITU-T and IEEE and will then drill down into detail with sessions focusing on: Ethernet based and Ethernet capable access networks; Ethernet network transport; Ethernet Bridging architecture; Ethernet OAM and management; Ethernet QoS, timing and synchronization. A closing session will bring together reports from all of the session chairs in order to identify the direction of future work.

Article on new fibre optic standard

Thu, 25 Jan 2007 14:59:46 GMT

Lightwave Europe has recently published an article on ITU-T Rec. G.655. The standard extends the use of fibre previously used mainly in core networks to metropolitan or regional networks. Crucially it also has the potential to greatly reduce operating costs for network providers.

See Lightwaves story here.

See ITU-T Newslog entry here.

New Home Networking Spec

Fri, 24 Nov 2006 10:10:49 GMT

ITU-Ts Study Group 15 has consented on a revision to a home networking specification that increases data rates over existing home wiring to 320 Megabits per second.

The original standard (ITU-T Recommendation G.9954) is based on input from the HomePNA alliance. The revision adds home networking over existing coax cables to networking over phone wires. The revision also includes new operating spectrums adding VDSL coexistence to the ADSL, POTS and broadcast TV channel spectrum coexistence provided by the original standard.

G.9954 facilitates interoperability and convergence of all networked IP data in the home by creating open, interoperable standards and best practices for a universal home networking market. Telephone service providers have collaborated with residential gateway, set-top box, bridge, consumer electronics (CE) equipment, and ONT manufacturers, as well as their component providers, to meet consumer demand for bundled multimedia home networking.

Home networking bandwidth requirements will steadily increase as operators deliver multi-stream high-definition content, upgrade last-mile access network technologies, and provision future IP-based services. Leveraging existing home wires, service providers can reduce installation, operational expenses and even end-user costs. Experts say that 320 Mbps can accommodate the future bandwidth requirements of service providers as they enhance their offerings with additional features and capabilities.

Smart network element defined in ITU-T Recommendation

Mon, 13 Nov 2006 14:11:27 GMT

A major step towards dynamic and reconfigurable smart networks has been made with the consent of a new standard.

Operators and manufacturers have pushed the development of the ITU-T Recommendation (G.667) that is the first for adaptive chromatic dispersion compensators.

Chromatic dispersion is a phenomenon that produces pulse broadening in optical fibers, and can limit the overall amount of data transported over them. In some applications, the chromatic dispersion of the optical path varies with time or optical network re-configuration to such an extent that, to avoid signal degradations at the receiver, an adaptive dispersion compensator is used to dynamically compensate the chromatic dispersion change of the optical link.

The automatic management of chromatic dispersion of the optical path, previously not standardized, means that for operators it will be much simpler to change the path of an optical channel in the optical network while maintaining the desired degree of chromatic dispersion. The standard allows for chromatic dispersion compensation to be controlled automatically in real time rather than operators having to manually change physical devices in the network.

The need for chromatic dispersion compensators is increasingly influenced by bit-rate as optical transmission systems are being upgraded from 10 to 40Gbit/s. Distance is also a factor as optical systems ultra long-haul - now extend to thousands of kilometers. In such situations the accumulation of chromatic dispersion variation with time or temperature of the optical path can exceed tolerance and therefore adaptive compensation is necessary. Network operation costs and flexibility should be favorably impacted by the ability to have chromatic dispersion compensation achieved automatically within the network.

New fibre standard simplifies FTTH rollout

Mon, 13 Nov 2006 09:21:17 GMT

ITU-T's Study Group 15 has fast tracked a standard that significantly reduces costs for operators rolling out fibre to the home (FTTH). The new Recommendation G.657 "Characteristics of a Bending Loss Insensitive Single Mode Optical Fibres and Cables for the Access Network" gives fiber optic cable similarly flexible characteristics to copper meaning that it can be much more easily deployed in the street, in the building and in the home.

This increased flexibility in a fibre optic cable means that operators can follow tighter corners in buildings, can employ less-skilled labor in deploying the cable and can worry less if cables / fibres are laid with a sharp bend. This all makes installation work more engineer friendly leading also to less re-work. Moreover the closures for fibres can be half the size, important where space is at a premium for example in an apartment building.

The new standard, which allows optical fibres to flex and bend more than the previous standardized types has achieved consent nearly a year earlier than was expected. This has been due to a push by operators planning the introduction of FTTH. Operators are keen that manufacturers around the world immediately start producing fibres according to the specification with clear advantages in terms of flexibility of deployment and cost reduction.

Many telcos have plans to roll out FTTH. The number of FTTH users in Japan exceeded 6 million as of mid 2006. According to experts the impetus for the work came from Japan , followed by the USA , but there is now much interest from European operators.

Online Event Targets VDSL2

Tue, 07 Nov 2006 08:16:51 GMT

John MacDonald, a member of the ITU team that created the new VDSL 2 standard, will take part in an upcoming Webinar on this topic, Tuesday, November 21. The Webinar, the second on the topic that ITU has contributed to, will outline what VDSL2 is, which are its competitive differentiators and benefits, and how it allows service providers to compete with cable and satellite operators - by enabling the delivery of enhanced voice, video and data services over a standard copper telephone cable.

ADSL (Asymmetric Digital Subscriber Line) is a product of ITU-T, ITUs standardization arm, and is the world's most widely deployed broadband access technology. It has enhanced users' experience of the Internet, provided access to digitized content, and fuelled the delivery of streaming video and the development of online gaming by offering downstream data rates of up to 8 Mbit/s. Today, service providers must ensure their DSL offerings can compete against other market options from cable operators. One way to do so, is by offering services over VDSL2 (ITU-T Recommendation G.993.2) - very high-speed DSL - a new version of DSL, which gives service providers the ability to deliver even higher bandwidth and more enhanced services to consumer and business customers.

Delivering up to 100 Mbit/s both up and downstream, a tenfold increase over ADSL (Asymmetric DSL) VDSL2 provides for so-called fiber-extension, bringing fiber-like bandwidth to premises not directly connected to the fiber optic segment of a telecom companys network. By deploying VDSL2 operators expect to be able to offer services such as high-definition TV (HDTV), video-on-demand, videoconferencing, high-speed Internet access, and advanced voice services. Importantly VDSL 2 offers carriers a solution that is interoperable with the DSL equipment many already have in place. In addition, VDSL 2 will work with both legacy ATM networks and next generation IP-based networks.

Telecom World: GPON Interop Demo

Tue, 31 Oct 2006 14:58:42 GMT

Telecom World, December 4-8, Kong Kong will see ITU-T members, and guests stage an interoperability showcase for fibre to the premises (FTTP) related standards.

On show will be gigabit passive optical network (G-PON) equipment built according to the ITU-T G.984 Recommendation. PON technology is used in the local loop to connect residential and SME end users premises in an all-fibre network.

The G-PON Pavilion features live demonstrations of G-PON equipment interoperability; with interoperability being a critical enabler to reducing G-PON equipment costs. Triple-play interoperability demonstrations are provided by the following device and equipment manufactures: AMCC, Cambridge Industries Group, Ericsson, FlexLight Networks, Fujitsu Network Communications, Hitachi, LS Cable, Mitsubishi Electric, NEC, Terawave Communications, and ZTE.

With PONs, signals are carried by lasers and sent to their destination without the need for active electronics. Carriers can realize significant savings with fiber sharing in the distribution network, equipment sharing in the Central Office and by eliminating the dependence on expensive active network elements.

Service Layer Interoperability for GPON Highlighted

Wed, 13 Sep 2006 08:42:06 GMT

Interoperability between equipment using the ITU-T Recommendation G.984 for passive optical network (G-PON) has been demonstrated at an independent test laboratory, KTL in Santa Clara , California .

PON technology is used in the local loop to connect residential and SME end users premises in an all-fibre network. The event organized by the Full Service Access Network (FSAN) Group demonstrated service level interoperability between several vendors.

ITU-T Recommendation G.984 enables line rates of 2.5 Gbps in the downstream (central office to customer) and 1.2 Gbps in the upstream (customer to central office) to handle the bandwidth requirements for services like HD IPTV, online-gaming, Ethernet services, VoIP and TDM over fibre. In addition it offers more efficient IP and Ethernet handling.

FSAN together with ITU have hosted a series of B-PON and G-PON interoperability events over the years. The recent event, involved voice, data and IPTV testing between the following system vendors: Calix, Cambridge Industries Group, Entrisphere, Fujitsu, Hitachi, Huawei, Iamba Networks, Mitsubishi Electric, NEC, Siemens, Terawave. Shenick provided IPTV and data testing with quality of experience (QoE) and performance assessment. Spirent provided its triple play test solution to verify voice, video, and data service performance and functionality with 'real world' scenarios. Corning provided the complete optical distribution network (ODN) for the event, including the optical fibre, cable, splitters, cabinet, terminal distribution system, and connectorized drop cables.

The multi-vendor G-PON systems were used to transport voice, data and IPTV between the optical networking terminals (ONTs) and the optical line terminals (OLTs). Service provisioning of triple-play services was done via the ONT management and control interface (OMCI). Detailed test cases where used to verify quality and performance of services in a multi-vendor environment.

"We are very pleased with the achievement of VoIP and IPTV as well as other services working across a mix of vendor equipment," said Michael Brusca, Verizon Communications, Chair FSAN Interoperability Task Group. "We have overcome the challenge of OMCI interoperability that built on our previous physical layer testing, within a year after specifying its enhancements. G-PON is now mature and ready for mass deployment."

Don Clarke, 21CN chief access designer for BT Wholesale: "We are actively supporting FSAN and the ITU-T in their endeavor to achieve interoperability for GPON equipment. Interoperability will help drive down costs and leverage innovation in the customer termination space."

A public G-PON Interop Showcase is planned for ITU TELECOM WORLD 2006 this December in Hong Kong .

Vote for the most influential standards work from ITU-T

Mon, 05 Jun 2006 07:05:08 GMT

As part of celebrations for the 50^th anniversary of ITU-T, you are invited to vote for the most influential standards work from ITU-T.

ITU work is behind many of the worlds most prevalent information and communications technologies. Choose here from our shortlist which you think has best shaped the ICT world of today, or feel free to suggest your own idea.

Online Event Examines VDSL 2 Migration

Mon, 20 Mar 2006 09:27:08 GMT

John McDonald, a member of the ITU team that created the new VDSL 2 standard, will take part in an upcoming Webinar on this topic, Monday, April 03. The Webinar hosted by Light Reading will look at this development and explore the significance and implications of the new standard for both operators and the enormous installed base of DSL subscribers.

ITUs new VDSL 2 (Very High-Speed DSL 2) standard (ITU-T Recommendation G.993.2) delivers up to 100 Mbit/s both up and downstream, a tenfold increase over ADSL (Asymmetric DSL). By doing so, it provides for so-called fiber-extension, bringing fiber-like bandwidth to premises not directly connected to the fiber optic segment of a telecom companys network.

VDSL 2 will allow operators to compete with cable and satellite providers by offering services such as high-definition TV (HDTV), video-on-demand, videoconferencing, high-speed Internet access, and advanced voice services, over a standard copper telephone cable.

As well as addressing fast-growing consumer demand for high-speed multimedia services, VDSL 2 offers carriers a solution that is interoperable with the DSL equipment many already have in place, expediting migration of customers to new VDSL 2-based products. In addition, VDSL 2 will work with both legacy ATM networks and next generation IP-based networks.

Ethernet and MPLS Work Progressed

Fri, 03 Mar 2006 11:21:50 GMT

Study Group 15 saw continued progress in its work on standards to support the end-to-end rollout of Ethernet and Multiprotocol Label Switching (MPLS). This work continues the evolution of the use of Ethernet as an enterprise technology into a carrier service, and supports MPLS from a wider network perspective.

Study group experts say that ITU is the only standards body looking to support the choice of either Ethernet or MPLS as an end-to-end network technology. In effect ITU is addressing both technologies as part of one packet transport network, focusing in addition on their seamless interoperability.

Work in the Ethernet field progressed at the February meeting aims to allow per user, service provider, and network operator service level monitoring and assurance; fault isolation to target maintenance and repair and to enable automatic protection switching, network management and the possibility of reuse of SDH management systems.

This work is based on, and enabled by the work recently completed on Ethernet operations, administration and maintenance (OAM) in Study Group 13 with their consent of new Recommendation Y.1731 (see story). The follow-on work in SG 15 includes amendments to the layer network architecture (G.8010/Y.1306) and the Ethernet equipment Recommendations (G.8021/Y.1341), and a new Recommendation on Ethernet protection switching (G.8031/Y.1342), which according to Study Group experts will give operators the opportunity to offer close to 100 per cent availability of Ethernet services for the first time. This is achieved using a system that uses a predefined alternative route if the most direct is broken.

In the field of MPLS a raft of new work aims to allow operators to adopt this technology end-to-end. MPLS is widely embraced in backbone networks as a way to speed up routers. Lately some have advocated its use further downstream in access networks, there have even been suggestions to extend this as far as customer premises. ITUs work seeks to support this, but additionally to allow the seamless interworking between Ethernet and MPLS. This has been progressed in SG 15 through the completion of a new set of Recommendations for Transport MPLS (T-MPLS), a technology which uses a subset of the components defined in the MPLS Layer Network Architecture of Recommendation G.8110 to support packet transport applications that adhere to ITU-T layer network architecture principles. A T-MPLS layer network can operate independently of its clients and its associated control networks (i.e., multi-carrier or single carrier networks (MCN, SCN) and can carry a variety of client traffic types. This independence affords network operators the freedom necessary to design robust packet transport networks for their own use and to transport customer traffic. T-MPLS is designed to behave consistently with existing transport technologies, thus offering the operational characteristics, performance and reliability that network operators require from carrier-class technologies. The new Recommendations for this technology cover the T-MPLS layer network architecture (G.8110.1/Y.1370.1), interfaces for the T-MPLS Hierarchy (G.8112/Y.1371), and T-MPLS Equipment (G.8121/Y.1381).

Amended Fibre Standard Gives Operator Savings

Mon, 27 Feb 2006 16:16:39 GMT

A revision to a commonly used ITU-T Recommendation will extend use of fibre previously used mainly in core networks to metropolitan or regional networks. Crucially it also has the potential to greatly reduce operating costs for network providers.

G.655 for non-zero dispersion-shifted fibre (NZDSF) was originally designed to support DWDM long distance core, it was designed to reduce a phenomenon called four wave mixing (an interaction between wavelengths that generates additional optical channels). The impressive improvement in dispersion profiles afforded by G.655 fibre together with the development of the G.692 standard for optical interfaces for multichannel systems with optical amplifiers led to an explosion in the market for DWDM systems experts say.

Reduced dispersion allows sending signals over greater distances without dispersion compensation, meaning that operators will be able to avoid using a compensator and amplifier as well as the costs associated with this; power, protection, housing and security.

The revision to G.655 (full title, Characteristics of a non-zero dispersion-shifted single-mode optical fibre and cable) deals with chromatic dispersion, a phenomenon which at low levels counteracts distortion, but at high-levels can make a signal unusable. The management of chromatic dispersion is crucial as the number of wavelengths used in WDM systems increases. ITU has a history of providing the specifications that allow operators to most efficiently handle this. The revision allows more efficient use of the properties of chromatic dispersion by more stringently defining its existence. It defines chromatic dispersion in two new categories that can be exploited by systems designers as necessary.

The need for the work stemmed from systems' designers want to better understand dispersion. And a result is that experts saw a use for G.655 cable in metro or regional networks where it had previously only been used in core networks.

End-to-End Visibility In Multi-Carrier Networks

Thu, 23 Feb 2006 07:19:05 GMT

A new Recommendation identifies the needs required to give end-to-end visibility of client services carried across multi-carrier networks. Without this ability carriers have often had to wait for customers to report problems before they can begin to address them.

The Recommendation - G.8601 - identifies the requirements for the next stage of work which will focus on methodologies to address this issue. Study group experts report that contributions to this end have already
been received.

G.8601 defines architectural requirements for the edge-to-edge management of client services transported over various transport network topologies and technologies. The services for which such management capabilities are required are also included.

The requirements for the transference of the management data between the edge points are described along with the requirements for accessibility to management information at some point in the network, other than the end point.

Optical Interface Rec Updated With FEC

Mon, 20 Feb 2006 08:44:25 GMT

G.959.1, the Recommendation that increased the capacity for multi-vendor optical interfaces developed to exploit the demand for high capacity Internet routers (see press release), has been updated to help further reduce costs for operators. The use of forward error correction (FEC) as defined in ITU-T Rec. G.709 will allow operators to transport data more cost-effectively through the use of lower cost electro-optics.

FEC is a method of sending redundant information with the data in one-way communication in order to allow the receiver to reconstruct the data if there was an error in transmission.

Experts say that in the last few years they have seen a shift in demand from operators who are now looking to maximize return on investment rather than increase distance covered etc. The revision of this Recommendation addresses this need.

This work forms part of ITUs ongoing work in optical transport networks (OTN) which encourages a fair market for manufacturers and operators, and ultimately encourages better service for consumers. It has been developed with input from the Optical Interworking Forum (OIF).

New Ethernet Services Made Possible by ITU Standards

Fri, 03 Jun 2005 07:10:54 GMT

A meeting of Study Group 15, the ITU-T group responsible for studies into optical and other transport network technologies, saw consent on a new Recommendation that defines the way for equipment providers to produce systems for Ethernet virtual private line (EVPL) services.

EVPLs offer a way for operators to provide point-to-point connections for carrying data over shared-bandwidth facilities.

The announcement is in line with the current industry trend to offer Ethernet services, and further signals Ethernet's growth in popularity as an enterprise telecom service.

Long-recognized as a ubiquitous LAN technology, Ethernet is now seeing increased attention as a carrier-grade service. In part this is due to the convenience of being able to simply provide end-to-end service, but also carriers can realize savings both in terms of capital and operational expenditure.

In terms of capital expenditure, Ethernet is easy and cost-effective to provision in the network. In terms of operational expenditure, carriers can deploy a single physical connection to the end user, but adapt its data-carrying capacity as end-user requirements dictate over time. This flexibility means a significant saving for the operator and the customer.

This work follows earlier work in the area of Ethernet standards approved last year. See also press release 8 June, 2004 .

The new Recommendation - G.8011.2 - defines the service attributes and parameters for carrying Ethernet characteristic information over shared-bandwidth, point-to-point connections, provided by SDH, ATM, MPLS, PDH, OTH, or ETY server layer networks.

Design Guidelines for Submarine Cable Systems Issued

Wed, 01 Jun 2005 09:39:33 GMT

ITU-T's Study Group 15 has agreed on design guidelines for optical fibre submarine cable systems.

Submarine cable systems form a very important part of the world's ICT network infrastructure with cables linking all the world's continents except Antarctica. And as demand for increased transmission capacity increases, owners of these networks are keen to optimize their investments, because laying new submarine cables is an expensive and difficult business.

The guidelines appear in a supplement to ITU-T Recommendations on the topic of submarine cable systems (Supplement 41, to the G series of ITU-T Recommendations), and allow for the incorporation of traditional technology (e.g. WDM systems, erbium doped fibre amplifiers) as well as new technology including new generation forward error correction (FEC) and Raman amplifiers.

According to the expert authors, the document has been produced with a key objective to detail the main technical issues to be taken into account in order to achieve a link's longest distance, with maximum reliability.

The supplement describes considerations for repeatered, repeaterless and optically amplified systems supporting synchronous digital hierarchy (SDH) and optical transport network (OTN) signals. Repeaterless submarine cable systems are used for terrestrial network extensions in cases where submarine distances up to about 350 km are to be covered. Repeatered submarine systems are used for long haul, large capacity transmission by using submerged optical amplifiers in order to cross distances up to transoceanic lengths.

ITU-T Recommendation Addresses Lightwave Phenomenon

Fri, 27 May 2005 11:54:31 GMT

A new ITU-T Recommendation specifies the characteristics for devices that address a phenomenon known as polarization mode dispersion (PMD) in optical fibres. PMD is caused by a difference of the propagation speed in different polarisations of the light travelling through a fibre. PMD is induced by distortion of the light in optical fibres that occur as a result of the manufacturing process, the way it is laid in the ground, around corners etc.

PMD becomes an increasingly serious problem as the bit rate and the length of optical transmission systems increase. As a result, PMD compensation (PMDC) is an important technology for very high rate long distance systems. For instance at 10Gbit/s PMD is manageable for currently existing long-haul dense wavelength division multiplexing (DWDM) systems but at 40Gbit/s compensation may become necessary.

While there has been knowledge of the phenomenon for some time the PMD-induced penalties such as distance and bit rate limitations have often been considered too difficult or expensive to deal with, and so the telecommunication industry has had to learn to live with the problem. There have been limited efforts to develop solutions which have not evolved into successful commercial products.

In order to address the problem in a more efficient manner and stimulate a market for PMD compensating devices, operators have driven this ITU-T work. By agreeing on a set of characteristics for these devices, operators can look forward to the availability of products that will be more mature and will cost less than developing in-house solutions. It is expected that operators may also see reduced expenditure because it is thought that the use this technology will reduce the need for electro-optical regenerators (devices that break a signal down in order to restore it to its original quality).

Future work of the group that has produced this Recommendation will look at similar devices called adaptive dispersion compensators for another phenomenon called chromatic dispersion that also limits data rates and transmission distances in optical fibres.