Recommendation ITU-T G.709/Y.1331 defines the requirements for the optical transport network (OTN) interface signals of the optical transport network, in terms of:
– OTN hierarchy
– functionality of the overhead in support of multi-wavelength optical networks
– frame structures
– bit rates
– formats for mapping client signals.
Edition 5.0 of this Recommendation includes the text of Amendments 2, 3, 4, Corrigendum 2 and Erratum 1 to Edition 4.0 of this Recommendation, support for frequency and time synchronisation, addition of Beyond 100 Gbit/s OTU, ODU and OPU frame formats, overhead, ODU multiplexing, client mappings and optical layer terminology updates. Edition 5.0 furthermore deleted the OPUk concatenation specifications and the ATM mapping into OPUk specification and changed the TCM ACT and FTFL overhead bytes into EXP overhead bytes.
Amendment 1 contains extensions to the fifth edition (06/2016) of Recommendation ITU-T G.709/Y.1331, related to the:
– Addition of paragraph that describes that ITU-T G.798 complements ITU-T G.709 (1)
– Addition of references to Recommendation ITU-T G.8260 (2)
– Addition of definitions and conventions that have been included in the past in ITU-T G.870 (3, 5)
– Deletion and addition of abbreviations (4)
– Addition of a sentence that describes that 3R regeneration is used on both sides of an interface interconnecting user and provider administrations and two provider administrations (6)
– Corrections to the STU, MOTU, SOTUm and MOTUm descriptions (8.1, 8.2, 8.3, 8.4)
– Addition of a note describing a vendor specific mode in the GCC0 communication channel deployment (15.7.2.2)
– Deletion of OTUCn OSMC (15, 15.7.1, 15.7.2.4, 15.7.2.4.1.2)
– Deletion of reference to concatenation (15.9.2)
– Aligning the OPUk/OPUflex clock performance requirement in case of BMP based client mapping with ITU‑T G.8251 and ITU-T G.798 (17.2, 17.19, 17.12)
– Clarify the 2-bit alignment when mapping 66-bit blocks into the OPUflex payload area (17.11, 17.12)
– Changing the minimum number of FlexE signals in a FlexE aware mapping into an OPUflex (17.12)
– Addition of 25GE client signal (2, 15.9.2.1.1, 17.13, 17.13.1)
– Deletion of ODUCn HAO reference (20.4.3.1).
Corrigendum 1:
– Deletes references to virtual concatenation (7, 15.9.1, 15.9.2.1, 15.9.2.2)
– Adds a note informing that OSC signals designed prior to Edition 5.0 may not support the added OTSiA trail and payload overhead (15.1.8)
– Changes the number of OPU3 Tributary Slots necessary to carry an ODUflex(IB DDR) signal from "4" to "5" in Table 7-9 (7-4)
– Changes the second instance of "OCh-FDI-P" to "OTSiA-FDI-P" in the first paragraph of clause 16.3.1
– Adds a new paragraph to clause 16.3.2 that defines the OTSiA-FDI-O signal
– Changes "ODTUC.ts" into "ODTUCn.ts" in the third dash item in clause 20.4.1.1
– Changes "2M-byte word" to "16M-byte word" in the last paragraph of clause 20.4.3.1
– Changes the description of "Inputs = C14, II, DI, CRC" in Figure D.8 into "Inputs = C14, II, and DI for the 14 bit count" plus "Inputs = C10, II, and DI for the 10-bit count". Deletes the text at the bottom of the figure.
Amendment 2:
– Adds the OTN mappings for the IEEE 802.3 200 Gbit/s and 400 Gbit/s Ethernet client signal
– Adds the eSSM message type for the OSMC
– Specifies OTSiG-O transport over the FlexO-LR SOTUm interface
– Adds reference to two FEC options for OTUk signals
– It also provides clarification regarding interfaces where OTUk and OTUCn section monitoring overhead is optional, and elaborates on OCh and OTSiA maintenance signals.
Amendment 3 contains extensions to the fifth edition (06/2016) of Recommendation ITU‑T G.709/Y.1331, related to the:
– Addition of interconnection of Ethernet UNI and FlexE Group UNI in two administrative domains (clause 7.5 of Appendix XIV).
– Addition of 50GBASE-R mapping into ODUflex (clause 17.13.3 of Annex J).
– Update of FlexE terminology and calendar slot descriptions with FlexE 2.0 IA (clauses 17.11 and 17.12).
– Redefine the OP overhead bit in bit 1 of JC6 as a RES overhead (clauses 20.4, 20.4.3.1 and 20.5).
– Replacement of references to IEEE Std. 802.3-2015, 802.3by and 802.3bs by a reference to IEEE Std 802.3-2018 (clauses 17.13.1 and 17.13.2, Annex J and Annex K).
– Addition of ODU4 and ODUflex(25G/50G/200G/400GBASE-R) rows to Table 7-9 (clause 7.4).
– Addition of 25G, 50G, 200G and 400GBASE-R rows to Table IX.1 (Appendix IX).
– Addition of ODUflex(25G/50GGBASE-R, FC-1600/3200) rows to Table X.1 (Appendix X). |
