[Devel] loop detection fix

[Daniel-Constantin Mierla]

On 09/08/06 09:51, Juha Heinanen wrote:
> there is an internet draft on detecting looping forked requests:
>
> draft-ietf-sip-fork-loop-fix-03
>
> that fixes loop detection mechanism of rfc3261.
>
> assuming that openser is configured to accept pre-loaded route header
> only for itself, it would suffice that openser calculates a hash
The issue is with hash value. Somehow should ensure unique values, but 
most algorithms dont. They recommend in draft to use md5 which has low 
probability of collision.

Also, Route set has to be taken in consideration. Not usre if R-URI and 
Routes have to be canonized -- r-uri to username/host/port/proto and 
route to host/port/proto.

Daniel


>  on
> received request uri and appends it to its via branch parameter (for
> example after a dot) for all parallel forked outgoing legs.
>
> when request comes in, openser should inspect all via headers that have
> its own ip address:port and that include the hash and then compare that
> hash to the one calculated from the current request uri.  if hashes
> match, openser would respond with 482 loop detected.
>
> what do you think about implementing this?
>
> -- juha
>
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