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[802.3_ITSA] regarding comment #251 in P802.3cx/D2.1

P802.3cx Task Force members:

From the last meeting, the following action remained for comment #251:

·                     For comment 251 there were concerns about the proposed resolution. It was stated that Clause 82.2.6 uses the wording “multiple PCS lanes”, we may use similar terminology. The resolution of comment 251 was deferred to the next meeting.”


I searched through some clauses of 802.3 that I know used the mechanism that we had called “multi-PCS lanes”.  I found that it consistently used the term “PCS lane(s)”, but not “multi-PCS lanes”.  See examples are shown below:

·                     From 82.2.6 (40GBASE-R and 100GBASE-R)

      • “Once the data is encoded and scrambled, it is distributed to multiple PCS lanes, 66-bit blocks at a time in a round robin distribution from the lowest to the highest numbered PCS lanes. This allows the PCS to support multiple physical lanes in the PMD and XLAUI or CAUI-n interfaces (see Annex 83A, Annex 83B, Annex 83D, and Annex 83E). The 40GBASE-R PCS distributes the 66-bit blocks to 4 PCS lanes, and the 100GBASE-R PCS distributes the blocks to 20 PCS lanes. The distribution process is shown in Figure 82–6.

·                     From 119.2.1 (200GBASE-R and 400GBASE-R)

      • “When communicating with the PMA, the 200GBASE-R PCS uses 8 encoded bit streams (also known as PCS lanes) and the 400GBASE-R PCS uses 16 encoded bit streams.”
      • The two FEC codewords are then interleaved before data is distributed to individual PCS lanes.”
      • It attains alignment marker lock based on the common marker (CM) portion that is periodically transmitted on every PCS lane. After alignment markers are found on all PCS lanes, the individual PCS lanes are identified using the unique marker portion (UM) and then reordered and deskewed. Note that a particular transmit PCS lane can be received on any receive lane of the service interface due to the skew and multiplexing that occurs in the path


Given this, I believe we should simply change “multi-PCS lanes” to “multiple PCS lanes”.


Also, there is single instance of “multi-FEC lane”.  For this, we should change “…multi-FEC lane distribution/merging operation” to “…multiple FEC lane distribution/merging operation”.  However, comment #7 suggests removing the sentence with this instance.  If this comment is accepted, then this problem is already resolved. 




Richard Tse

Sr Technical Staff Engineer – Architect

Microchip Technology

8555 Baxter Place

Burnaby, BC


V5A 4V7

Phone:  +1-604-415-6015

Email:  Richard.Tse@xxxxxxxxxxxxx



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