[Spce-user] 483 Too Many Hops

Andreas Granig agranig at sipwise.com
Sun Mar 24 12:43:18 EDT 2013


Hi,

On 03/24/2013 05:25 PM, Lorenzo Mangani wrote:
> As you can see from your trace, the call is never completely
> established, as the 200 OK's ACK never makes it back to the user-agent.
> After a brief look this seems to be caused by the gateway always using
> the contact header to respond instead of the from header, as for the BYE
> message also being rejected for the same reason - just my 2 cents, might
> be wrong - maybe someone else on the list will have different input,
>

The Contact handling is as expected, but the 208.73.198.12 doesn't 
convert the Record-Route headers added by the SPCE in the 200-OK (packet 
#14) into Route headers of the ACK (packet #15), so the proxy has no 
information where to relay the ACK to (note that ACKs to 200 are relayed 
end-to-end, so all Route information must be preserved).

The sender of the ACK *must* take the Record-Route headers of the 
previous 200-OK, convert them to Routes and add them to the message in 
reverse order, and send the request to the URI found in the top-most Route.

Andreas




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