public icon indicating copy to clipboard operation
public copied to clipboard

Add support for QSFP56 and QSFP56_DD_TYPE3 form factor identities

Open LeonGWang opened this issue 3 years ago • 9 comments

QSFP56-DD transceiver form-factor encompasses more variants than just type1 (8 optical signals) and type2 (4 optical signals) defined in OpenConfig.

We should either use an umbrella QSFP56-DD identity to encompass all variants, or add an additional identity to represent QSFP-DD 400G-ZR (1 optical signal).

LeonGWang avatar Jan 25 '22 19:01 LeonGWang

Compatibility Report for commit da629ae05b78098adedb16da2664b8e1667b6560: ✅ pyangbind@b1762a3

OpenConfigBot avatar Jan 25 '22 19:01 OpenConfigBot

@ejbrever can you provide any comments?

dplore avatar Jan 26 '22 02:01 dplore

I think there was some desire to specify the types, so keeping with that I'd lean towards adding the Type3 as done here.

Adding an umbrella QSFP56 type might be problematic though because it allows for vendor implementations to choose either a specific type or the generic one, so we will likely have inconsistencies between implementations.

ejbrever avatar Jan 27 '22 20:01 ejbrever

I updated my commit to only keep the backward compatible QSFP56_DD_TYPE3 identity. I also added a QSFP56 identity that is missing in the OpenConfig model.

LeonGWang avatar Jan 29 '22 00:01 LeonGWang

This looks good to me.

@thofmeister @yawei-yin would either you be able to review this as well? Thanks.

ejbrever avatar Jan 31 '22 19:01 ejbrever

We might need an identity QSFP56_DD to cover all the QSFP56-DD types. The count of optical lanes can be identified by ETHERNET_PMD_TYPE. For instance, TYPE2 corresponds to ETH_400GBASE_FR4, ETH_400GBASE_LR4, ETH_400GBASE_DR4, while TYPE1 corresponds to ETH_400GBASE_SR8, ETH_400GBASE_LR8. Therefore, we need to delete QSFP56_DD_TYPE1 and QSFP56_DD_TYPE2.

@ejbrever @yawei-yin @thofmeister Actually, this issue has been addressed by PR#1016. We could revisit it in this public PR, and I will close PR#1016. What do you think?

jqjqlee avatar Feb 02 '22 04:02 jqjqlee

BTW, could we add more peer identities in a single PR, such as QSFP112, and QSFP112_DD which will be soon commercially available. For each generation of form factor, we are facing similar issue to what this PR addressed. That is, each form factor would have multiple variants/types in terms of optical interface standard. In this regards, it is suggested to decouple the form factor identities from optical interface specifications.

jqjqlee avatar Feb 02 '22 04:02 jqjqlee

@ejbrever can you also follow up with @thofmeister offline for us?

dplore avatar Oct 11 '22 18:10 dplore

I think there was some desire to specify the types, so keeping with that I'd lean towards adding the Type3 as done here.

Adding an umbrella QSFP56 type might be problematic though because it allows for vendor implementations to choose either a specific type or the generic one, so we will likely have inconsistencies between implementations.

@ejbrever Eric, if we still maintain multiple identities/types for QSFP56-DD form factor, how could we cope with other form factors? Other form factors have multiple variants/types in implementation as well. This would result in inconsistency among different form factors. In order to reach a consensus, could we keep a generic identity QSFP56_DD in parallel to QSFP56_DD_TYPE1, QSFP56_DD_TYPE2 and the newly-proposed QSFP56_DD_TYPE3? So the vendors can select what they would like to implement.

jqjqlee avatar Oct 11 '22 18:10 jqjqlee

Major YANG version changes in commit da629ae05b78098adedb16da2664b8e1667b6560:

OpenConfigBot avatar Jul 24 '23 09:07 OpenConfigBot

Hi all, this PR is stalled. Could we let this PR merge as a band-aid solution and discuss refactoring and/or backward-incompatible changes to transceiver identities in a separate issue/PR?

Many thanks for considering my request.

LeonGWang avatar Jul 24 '23 09:07 LeonGWang

@dplore Do you have any opinions or suggestions for this PR? This PR is similar to PR #585

Thanks in advance!

LeonGWang avatar Jul 24 '23 22:07 LeonGWang

QSFP56_DD in parallel to QSFP56_DD_TYPE1, QSFP56_DD_TYPE2 and the newly-proposed QSFP56_DD_TYPE3

@ejbrever can you take another look here?

In my opinion we should have a different transceiver form factor type whenever the physical packaging and/or electrical interface changes. Further, it seems useful to only define transceiver form factor types that are a discreet, installable part. A transceiver form factor that aggregates multiple incompatible electrical interfaces (even if backwards compatible) seems like it's not a useful type to define.

dplore avatar Jul 25 '23 01:07 dplore

Gentle bump

LeonGWang avatar Jul 31 '23 19:07 LeonGWang

Hi Leon, after some internal discussion we came to the following recommendation:

Introduce a new identity of "QSFP56_DD". This should be inclusive of type 1,2,3. Please add a reference statement to the MSA for QSFP56_DD.

Change the existing identities of QSFP56_DD_TYPE1 and QSFP56_DD_TYPE2 to be deprecated. (Use the yang status: deprecated statement)

The rationale is that the TYPE 1,2,3 variations are not configuration or state that is reported by the device. Furthermore, it is our understanding that the physical form factor / cage for Type 1,2,3 devices is interchangable. This is based on our understanding on the specifications for QSFP56_DD. Please feel free to provide references if our conclusion is not well informed.

Also, this may be obvious, but for community documentation benefit, I wanted to mention to differentiate link speeds delivered, the PMD is used.

dplore avatar Aug 01 '23 18:08 dplore

Hi Leon, after some internal discussion we came to the following recommendation:

Introduce a new identity of "QSFP56_DD". This should be inclusive of type 1,2,3. Please add a reference statement to the MSA for QSFP56_DD.

Change the existing identities of QSFP56_DD_TYPE1 and QSFP56_DD_TYPE2 to be deprecated. (Use the yang status: deprecated statement)

The rationale is that the TYPE 1,2,3 variations are not configuration or state that is reported by the device. Furthermore, it is our understanding that the physical form factor / cage for Type 1,2,3 devices is interchangable. This is based on our understanding on the specifications for QSFP56_DD. Please feel free to provide references if our conclusion is not well informed.

Also, this may be obvious, but for community documentation benefit, I wanted to mention to differentiate link speeds delivered, the PMD is used.

Finally, the consensus is reached. :-)

jqjqlee avatar Aug 01 '23 18:08 jqjqlee

Thanks for the feedback @dplore and @jqjqlee!

The QSFP56_DD form factor identity has been added instead of a TYPE3 variant. TYPE1/2 identities are also marked as deprecated as per consensus.

I still left the QSFP56 identity as-is, continuing to use the same description language as the existing QSFP28. Let me know if changes are required for that identity.

LeonGWang avatar Aug 03 '23 07:08 LeonGWang