Re: [tsvwg] SCTP RANDOM parameter in case of INIT collision

[Michael Tuexen <[e-mail]>]

> On 1. Mar 2019, at 14:05, Proshin, Maksim <[e-mail]> wrote:
> 
> Hi Michael, tsvwg,
>  
> I have a doubt about the RANDOM parameter from RFC 4895 which was caused by interoperability tests with different SCTP implementations.
> RFC 4895 has the following text in Section 6.1:
>    In case
>    of INIT collision, the rules governing the handling of this Random
>    Number follow the same pattern as those for the Verification Tag, as
>    explained in Section 5.2.4 of RFC 2960 [5].  Therefore, each endpoint
>    knows its own Random Number and the peer's Random Number after the
>    association has been established.
>  
> and RFC 4960 which obsoletes RFC 2960 has the following statement in Section 5.2.1:
>  
>    Upon receipt of an INIT in the COOKIE-WAIT state, an endpoint MUST
>    respond with an INIT ACK using the same parameters it sent in its
>    original INIT chunk (including its Initiate Tag, unchanged).
>  
> Based on those 2 statements I assume that SCTP must always respond with the same Random Number when it sends INIT ACK in response to INIT received in the COOKIE-WAIT state. Is my understanding correct?    
Yes, I would say so.

Is an open source implementation not following these rules?

Best regards
Michael
>  
> BR, Maxim