IEEE Std 802.3cc-2017 pdf download – IEEE Standard for Ethernet Amendment 1 1 : Physical Layer and Management Parameters for Serial 25 Gb/s Ethernet Operation Over Single-Mode Fiber.
105. Introduction to 25 Gb/s networks 105.1 Overview 105.1.1 Scope Change the first paragraph of 105.1.1 (as inserted by IEEE Std 802.3by-2016 and modified by IEEE Std 802.3bq-2016) as follows: 25 Gigabit Ethernet uses the IEEE 802.3 MAC sublayer, connected through a 25 Gigabit Media Independent Interface (25GMII) to Physical Layer entities such as 25GBASE-CR, 25GBASE-CR-S, 25GBASE-KR, 25GBASE-KR-S, 25GBASE-SR, and 25GBASE-T, 25GBASE-LR, and 25GBASE-ER. 105.1.2 Relationship of 25 Gigabit Ethernet to the ISO OSI reference model Change item c) of 105.1.2 (as inserted by IEEE Std 802.3by-2016) as follows: a) The Media Dependent Interface (MDI) as specified in Clause 110 for 25GBASE-CR and 25GBASE-CR-S, in Clause 111 for 25GBASE-KR and 25GBASE-KR-S, or in Clause 112 for 25GBASE-SR, or in Clause 114 for 25GBASE-LR and 25GBASE-ER uses a single-lane data path. 105.1.3 Nomenclature Change the second paragraph of 105.1.3 (as inserted by IEEE Std 802.3by-2016) as follows: The term 25GBASE-R refers to a specific family of Physical Layer implementations based upon the 64B/66B data coding method specified in Clause 107. The 25GBASE-R family is composed of 25GBASE-CR, 25GBASE-CR-S, 25GBASE-KR, 25GBASE-KR-S, and 25GBASE-SR, 25GBASE-LR, and 25GBASE-ER.
108. Reed-Solomon Forward Error Correction (RS-FEC) sublayer for 25GBASE-R PHYs 108.5 Functions within the 25GBASE-R RS-FEC sublayer 108.5.3 Receive function 108.5.3.2 Reed-Solomon decoder Change the third paragraph of 108.5.3.2 (as added by IEEE Std 802.3by-2016) as follows: The Reed-Solomon decoder may provide the option to perform error detection without error correction to reduce the delay contributed by the 25GBASE-R RS-FEC sublayer. The presence of this option is indicated by the assertion of the FEC_bypass_correction_ability variable (see 108.6.4). When the option is provided, it is enabled by the assertion of the FEC_bypass_correction_enable variable (see 108.6.1). This option shall not be used when the 25GBASE-R RS-FEC sublayer is used to form part of a 25GBASE-SR, 25GBASE-LR, or 25GBASE-ER PHY.