I am trying to think why IP (as distinct from TCP / QUIC / ..) would
care about ordering at all. I suppose the corner case of reordered
fragments could be considered relevant to IP. But mostly, this seems to
belong at transport, not IP.
Yours,
Joel
PS: I think the wording in the draft coul
Fragment reassembly is one reason. Another non-transport reason is IPsec
replay. But in both cases, it’s not just ordering that matters; it varies
depending on whether the stream is reordered in isolation or different
reordered streams are concurrent.
- in all cases, reordering matters within i
Hi, Greg,
My point is different; I’m not suggesting getting into the details - the point
is that IP isn’t the only reason L2s try to enforce ordering.
If an L2 needs ordering for other reasons, then that’s just the “cost of using
that L2”, not something that the IP layer should suggest can/shou
Thanks Joe.
Yes, that could be case, but IMO it would be out of scope for the draft to
explore non-IP use cases.
Perhaps the goal of this document could be described as gathering the current
wisdom around the implications, positive and negative, of L2 resequencing on IP.
Greg
On Mar 12, 2025,
Hi Greg,
FWIW, it might be useful to note that some L2s maintain ordering for their own
purposes, e.g., ATM did so to simplify fragmentation and reassembly in its own
protocol layers. Others may rely on in-order delivery for control messages (do
Ethernet BPDUs require this?).
I.e., it’s not al
