Re: Number of streams in SCTP Association

Thanks Chris, Thanks Padmalochan.

Would the M2PA also use more than 2 streams, or is there a restriction
there?

Regards,
Aditi

On Tue, Jun 21, 2011 at 2:48 AM, Chris Benson <[email protected]> wrote:

> Aditi,
>
> The first sentence in your email content is correct.
> The number of streams in an SCTP association is determined
> (negotiated) by the two end-point SCTP users.  A specific
> implementation of SCTP may restrict the maximum number of
> streams that it can support, but that number will typically
> be MUCH greater than 2 streams in each direction.
>
> One example SCTP-user is M3UA, and its RFC 4666 states in
> Section 1.4.7. SCTP Stream Mapping:
>   1. The DATA message MUST NOT be sent on stream 0.
>   2. The ASPSM, MGMT, RKM classes SHOULD be sent on stream 0
>      (other than BEAT, BEAT ACK and NTFY messages).
>   3. The SSNM, ASPTM classes and BEAT, BEAT ACK and NTFY
>      messages can be sent on any stream.
>
> The existence of the MUST NOT words in point 1. means that
> M3UA requires SCTP to support two streams in each direction,
> and it would like quite a few more.
>
> Note that in my example the "user" that decides and negotiates
> the number of streams is M3UA (the user of SCTP), and not a
> human user.
>
> Typically, SCTP-user protocols might expect that considerably
> more than two SCTP streams will be available if requested.
>
> With thanks, from Chris Benson.
>
> On Mon, 20 Jun 2011, aditi someshwar wrote:
>
> >>  Date: Mon, 20 Jun 2011 19:00:52 +0530
> >>  From: aditi someshwar <[email protected]>
> >>  To:  <[email protected]>
> >>  Subject: [Sigtran] Number of streams in SCTP Association
> >>
> >>  Dear all,
> >>
> >>
> >>  Need one clarification please:
> >>
> >>
> >>  NUMBER OF STREAMS WITHIN AN SCTP ASSOCIATION - In quite a few RFCs, it
> is
> >>  mentioned that the NUMBER OF STREAMS within one SCTP Association can be
> USER
> >>  DEFINED, & that the two end-nodes NEGOTIATE these at the time
> "Association
> >>  Set Up". However, REPEATEDLY, these RFCs also suggest that STREAM 0
> shall be
> >>  used for interchange of CONTROL MESSAGES while STREAM 1 (Note: They
> call it
> >>  STREAM-1, & NOT "other than Stream 0") carries Data.
> >>
> >>  It is NOT very clear if the RFCs THEMSELVES are specifying / suggesting
> that
> >>  AT MAX, there should be ONLY TWO STREAMs OR is it more a DEFAULT by
> most
> >>  PRODUCT MANUFACTURERS who have (to keep matters less complex) decided
> to
> >>  IMPLEMENT only TWO STREAMS.
> >>
> >>
> >>  Thanks and Regards,
> >>
> >>  Aditi
> >>
>

_______________________________________________
Sigtran mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/sigtran