Subject: Re: [tsvwg] DCCP Multipath Sequence Number

From: <[email-masked]>
Date: Mon, 1 Mar 2021 13:06:39 +0000

Dear Somsak,

yes indeed, we use two separate sequencing spaces. One belonging to the individual DCCP flows within the multipath connection as specified in RFC4340. The other, where you refer to, is belonging to the multipath connection (MP-DCCP connection) across the multiple DCCP flows and is newly introduced with the MP_SEQ option.

We see a benefit on having this separated for adjustable in-order delivery. More information you can found in a separate document under https://tools.ietf.org/html/draft-amend-iccrg-multipath-reordering-02#section-5 and in particular https://tools.ietf.org/html/draft-amend-iccrg-multipath-reordering-02#section-5.6.

But maybe we should make this clearer in the next revision of the draft. Thanks for raising this lack of clarity.

(I copy this conversation to [email-masked] with the approval from Somsak. For some technical reasons it did not work for him.)

Br

Markus

> From: Somsak Vanit-anunchai <[email-masked]> 
> Sent: Montag, 1. März 2021 09:11
> To: Amend, Markus <[email-masked]>
> Subject: DCCP Multipath Sequence Number
>
>
> Dear Markus
> I am currently reading  "draft-amend-tsvwg-multipath-dccp-04" .  On page 13, item 3.2.5  MP_SEQ shows 32 bits Multipath Sequence Number.
> However DCCP sequence number is either 48 or 24 bits.  
> Is the   Multipath Sequence Number the  same thing as  DCCP sequence number?
>
> Best regards,
> Somsak Vanit-Anunchai