Page 622 - Cloud computing: From paradigm to operation

3 XaaS

vFW virtual Firewall

vRouter virtual Router
VDI Virtual Desktop Infrastructure

VM Virtual Machine
VoIP Voice over IP

VPLS Virtual Private LAN Service
VPN Virtual Private Network
VRF Virtual Routing and Forwarding

WAN Wide Area Network

5 Conventions
The keywords "is required to" indicate a requirement which must be strictly followed and from which no
deviation is permitted if conformance to this Recommendation is to be claimed.
The keywords "is recommended" indicate a requirement which is recommended but which is not absolutely
required. Thus this requirement need not be present to claim conformance.
The keywords "can optionally" indicate an optional requirement which is permissible, without implying any
sense of being recommended. This term is not intended to imply that the vendor's implementation must
provide the option and the feature can be optionally enabled by the network operator/service provider.
Rather, it means the vendor may optionally provide the feature and still claim conformance with the
specification.
In the body of this Recommendation and its annexes, the words shall, shall not, should, and may sometimes
appear, in which case they are to be interpreted, respectively, as is required to, is prohibited from, is
recommended, and can optionally. The appearance of such phrases or keywords in an appendix or in material
explicitly marked as informative is to be interpreted as having no normative intent.

6 General description

6.1 Networking challenges in cloud computing
There are several challenges to build an efficient and reliable network application and infrastructure to
provide cloud services. Having both compute, storage and network capabilities may face the following
challenges:

• Coordination of compute and storage virtualization with network capabilities
Compute and storage performance challenges in cloud computing systems are successfully solved
using virtualization as a core technique. Server virtualization introduced virtual machines' (VMs)
dynamic and static migration, which imposes demands on the networking environments. Network
is expected to provide suitable and flexible support for highly variable cloud applications, when they
run inside complex and diverse system architecture. In such system it is possible to provide the
compute and storage resources, but it is also expected to dynamically provide the necessary
networking support required to assure overall system performance, reliability and quality of service
(QoS) demands.

• Harmonized control of heterogeneous network technologies
Due to the increasing geographical distribution of cloud computing systems several network
technologies can be utilised to assure end-to-end connectivity. It is expected that support of
efficient control mechanisms for heterogeneous network technologies be provided.

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