Re: [Detnet] The new d-ACH format

"Yangfan(Fan,IP Standards)" <> Wed, 17 November 2021 10:26 UTC

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From: "Yangfan(Fan,IP Standards)" <>
To: Greg Mirsky <>, DetNet WG <>
CC: DetNet Chairs <>
Thread-Topic: [Detnet] The new d-ACH format
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Date: Wed, 17 Nov 2021 10:26:13 +0000
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Subject: Re: [Detnet] The new d-ACH format
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Hi Greg,

Regarding the new d-ACH format, I have a few questions to share, hopefully trigger more discussions.

1)       I feel we need more specifications of Node ID.  Using 20 bits to indicate a Node in MPLS data plane, can I deduce it is an MPLS label? In any MPLS data planes except SR-MPLS, there is no definition to use a label to identify a node. If we want a format generic for all MPLS data planes, I wonder whether node id is a good indicator? Whether 20 bits is enough?

2)       I also noticed there is a session ID, but is only 4 bit length, which I believe is way too short. Moreover, whether originator node ID and session ID are duplicated here to identify an OAM session. To dig deeper, DetNet OAM should be stateless or stateful?

3)       if we plans to take advantages of CFM y.1731 mechanisms,  level and flags are necessary but the length also needs further considerations.

Looking forward to further discussions.


From: detnet [] On Behalf Of Greg Mirsky
Sent: Wednesday, November 17, 2021 4:55 AM
To: DetNet WG <>
Cc: DetNet Chairs <>
Subject: Re: [Detnet] The new d-ACH format

Dear All,
I hope you've recovered from the IETF-112 (timing on the West Coast was brutal).
Please share your thoughts, comments, and questions about the proposed new format of d-ACH and whether you support including it and updating draft-ietf-detnet-mpls-oam.


On Wed, Nov 10, 2021 at 5:14 AM Greg Mirsky <<>> wrote:
Dear All,
Bala'zs has presented the new d-ACH (DetNet Associated Channel Header) format at the DetNet WG meeting. Earlier this week, the new d-ACH format was presented at joint PALS, MPLS, and DetNet meeting and received several positive comments. At the DetNet WG meeting, it was proposed to integrate the technical part, the new format of d-ACH<> into the draft-ietf-detnet-mpls-oam<>.
Please, respond with the indication of your support or no support for the proposed update of the WG document.

Greg (as the Editor of draft-ietf-detnet-mpls-oam)