[Detnet] About the E2E latency of C-SCORE

peng.shaofu@zte.com.cn Fri, 22 March 2024 07:35 UTC

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Subject: [Detnet] About the E2E latency of C-SCORE
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Hi Jinoo,

Thank you for patiently explaining the latency of C-SCORE during the meeting. 
I just check the E2E latency equation provided in draft-joung-detnet-stateless-fair-queuing-02, it is:
    Dh(p) <= (B-L)/r + SL0 + SL1 + ... + SLh,     (5)

Now I realize that we are talking about different things.
The PBOO (pay bursts only once) you mentioned is actually (B-L)/r, right ?
But I (and maybe there are other people who also pay more attention to the worst-case latency per-hop), am more concerned about SL0 + SL1 + ... + SLh, that is actually an evaluation formula based on the worst-case latency per-hop multiplied by the number of hops.

IMO, (B-L)/r is negligible, especially when the flow is policing on the network entrance node and B = L.
That is, the worst-case per-hop latency SLi on each node i is the dominator factor.

Please correct me if I have any misunderstanding.

Regards,
PSF