Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [802.3_DWDM] Link degrade - Comment #246

Leon,

 

I made some updates in the attached.

 

I think basically the FEC degrade signaling should be identical to that for 400GbE as described in Clause 116, 118 and 119, with the following exceptions:

 

  • PCS (local degrade) : am_sf<1>  is replaced by STAT<7>
  • PCS (remote degrade): am_sf<2> is replaced by STAT<6>

 

I split your slide 2 into two new slides (slide 3 and 4 in the attached) to separate the local and remote degrade signaling as was done in Clause 116 (see Figure 116-7 and Figure 116-8)

 

I also cc’ed Dave and Jeff who were heavily involved with the definition of FEC degrade signaling in 3bs,  to make sure I didn’t miss something !

 

Gary

 

 

From: Leon Bruckman <0000177f9242b9c8-dmarc-request@xxxxxxxxxxxxxxxxx>
Sent: Monday, June 5, 2023 2:54 AM
To: STDS-802-3-DWDM@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_DWDM] Link degrade - Comment #246

 

Hi,

 

Attached are a couple of slides that show how the degrade indications flow according to my proposal below.

 

Best regards,

Leon

 

From: Leon Bruckman <0000177f9242b9c8-dmarc-request@xxxxxxxxxxxxxxxxx>
Sent: יום א 04 יוני 2023 11:56
To: STDS-802-3-DWDM@xxxxxxxxxxxxxxxxx
Subject: [802.3_DWDM] Link degrade - Comment #246

 

Hi,

 

Regarding the local and remote degrade issue, related with comment #246 from Eric.

 

Note that the draft does include a FEC_degraded_SER indication (see Table 155–9—MDIO/PCS and PMA status variable mapping).

 

My updated proposed resolution:

 

  • Transmit STAT
    • Actual text in 155.2.5.5.2:

 

If there is an adjacent PHY 400GXS sublayer then the value of remote degrade in STAT<6> is equal to the value of rx_am_sf<2> from the 400GXS sublayer, and local degrade in STAT<7> is equal to the value of rx_am_sf<1> from the 400GXS sublayer.

 

If there is no adjacent PHY 400GXS sublayer, meaning that the 400GBASE-ZR PCS is directly connected to a MAC-RS, then the value of remote degrade in STAT<6> is set to the value of local degrade in STAT<6> of the received status octet in the receive direction of the 400GBASE-ZR PCS, and the value of local degrade in STAT<7> in the transmit direction is set to 0.

 

    • Change to:

 

If there is an adjacent PHY 400GXS sublayer then the value of remote degrade in STAT<6> is set to 1 if rx_am_sf<2> from the 400GXS sublayer is set to 1 or FEC_degraded_SER is set, and to 0 otherwise, and the value of local degrade in STAT<7> is set to the value of rx_am_sf<1> from the 400GXS sublayer.

 

If there is no adjacent PHY 400GXS sublayer, meaning that the 400GBASE-ZR PCS is directly connected to a MAC-RS, then the value of remote degrade in STAT<6> is set to one if STAT<7> of the received status octet in the receive direction of the 400GBASE-ZR PCS is set to 1 or FEC_degraded_SER is set, and to 0 otherwise, and the value of local degrade in STAT<7> is set to 0.

 

  • Receive STAT
    • Actual text in 155.2.6.7.2:

 

If there is an adjacent PHY 400GXS sublayer, then the value of remote degrade in the received STAT<6> is passed to tx_am_sf<2> in the transmit direction of the 400GXS sublayer, and local degrade in STAT<7> is passed to tx_am_sf<1> in the transmit direction of the 400GXS sublayer.

 

If there is no adjacent PHY 400GXS sublayer, meaning that the 400GBASE-ZR PCS is connected to a MAC-RS, then the value of remote degrade in STAT<6> is passed to the DTE management entity to indicate a remote degrade event, and local degrade in the received STAT<7> is passed to the remote degrade bit in STAT<7> in the transmit direction of the 400GBASE-ZR PCS.

 

    • Change to:

 

If there is an adjacent PHY 400GXS sublayer, then the value of remote degrade in the received STAT<6> is passed to tx_am_sf<2> in the transmit direction of the 400GXS sublayer, and tx_am_sf<1> in the transmit direction of the 400GXS sublayer is set to one if local degrade in STAT<7> is set to 1 or FEC_degraded_SER is set, and to 0 otherwise.

 

If there is no adjacent PHY 400GXS sublayer, meaning that the 400GBASE-ZR PCS is connected to a MAC-RS, then the value of remote degrade in STAT<6> is passed to the DTE management entity to indicate a remote degrade event, and local degrade in the received STAT<7> is passed to the transmit direction of the 400GBASE-ZR PCS.

 

Please let us now your opinion

 

Leon

To unsubscribe from the STDS-802-3-DWDM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-DWDM&A=1

To unsubscribe from the STDS-802-3-DWDM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-DWDM&A=1

To unsubscribe from the STDS-802-3-DWDM list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-DWDM&A=1

Attachment: bruckman_3cw_01_010623)_gary_comments.pptx
Description: bruckman_3cw_01_010623)_gary_comments.pptx