Hi Joe, see annotations below: Thank you - Fred
From: [email protected] <[email protected]> Sent: Monday, September 30, 2024 8:30 AM To: Templin (US), Fred L <[email protected]> Cc: C. M. Heard <[email protected]>; Brian Carpenter <[email protected]>; Gorry (erg) <[email protected]>; Tim Chown <[email protected]>; Internet Area <[email protected]>; IPv6 List <[email protected]>; tsvwg IETF list <[email protected]> Subject: [EXTERNAL] Re: [tsvwg] UDP options [was IP Parcels and Advanced Jumbos (AJs)] On Sep 30, 2024, at 8:08 AM, Templin (US), Fred L <[email protected]<mailto:[email protected]>> wrote: > Please review the UDP options doc. There is no “end *following* UDP options”; > the options consume the entire surplus space. Yes, so IP parcels and AJs will update the base UDP options spec. For IP parcels and AJs, a 2-octet trailer can then be added beyond the end of the UDP options space. In UDP options for <64K, the IP length field indicates the end of the options space. The UDP length indicates the payload. UDP options consume the difference between the two. >> Yes, the same is true for parcels/AJs < 64K, except that the overall length >> appears in the Parcel Payload Length >> of the HBH option instead of in the IP length field. The same as for >> ordinary packets, though, the UDP length >> indicates the end of the payload and the beginning of the options. The >> difference between these two lengths >> also gives the length of the included options. For parcels, where is that information as distinct from those to items? Further, there are numerous other places where UDP options assume a 64KB limit (e.g., FRAG). All that would need to be worked out in detail to consider whether the two could co-exist, if and when we think we actually need support for beyond 64K. >> For parcels/AJs >= 64K, the overall length appears in the Parcel Payload >> Length of the HBH option and >> the UDP length is set to 0. The IP parcels draft specifies that UDP Length = >> 0 means that there will be >> a trailing 2-octet UDP Option Length field beyond the end of what would be >> considered the UDP options. >> The trailing field is not part of the UDP options, but is used to determine >> the starting offset and length >> of the UDP options. Again, this is only for parcels/AJs >= 64K. Joe
_______________________________________________ Int-area mailing list -- [email protected] To unsubscribe send an email to [email protected]
