[SIPForum-discussion] LOOP CALL

[vijay kant gupta]

There are two case in sip.
first is loopback that is an error. In this Scenario. the A party send to
proxy now proxy has to fwded B party but proxy fwded itself without change
in via method.
Second is Spiral method in A party  fwd to proxy but proxy change in via
method  to itself.
spiral is not an error.

On Wed, Aug 20, 2008 at 11:01 AM, Mishra2, Abhishek (NSN - IN/Bangalore) <
abhishek.mishra2 at nsn.com> wrote:

> Hi Nitin
>
>  The  Requests that arrive at a proxy, is forwarded  and later arrives
> back at the same proxy are treated as loop requests provided:
> (a) Via header branch parameter value matches to previous requests by
> the proxy
>
> SIP provides following mechanism for loop detection and prevention:
> MAX-Forwards
> ========
> (i) Counter decremented by 1 on every hop
> (II) Discard request when it is zero
>
> VIA
> ===
> (i)  Every proxy inserts an address
> (ii) Check for my address (proxy address) when the request comes
>
>
> Loop requests are errors
>
> Hope that this helps
>
> Bye
> Abhishek
>
> -----Original Message-----
> From: discussion-bounces at sipforum.org
> [mailto:discussion-bounces at sipforum.org] On Behalf Of ext nitin kapoor
> Sent: Wednesday, August 20, 2008 3:44 AM
> To: discussion at sipforum.com
> Subject: [SIPForum-discussion] LOOP CALL
>
> Hello Everyone
>
> I just wants to know  about the LOOP CALL. what does it mean. Why we are
> using this.
>
> Please let me know because i wants to know ASAP.
>
> Regards
> Nitin Kapoor
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