[SR-Users] Last negative 5XX reply not getting relayed

Alex Balashov abalashov at evaristesys.com
Tue May 15 09:51:22 CEST 2018

On Tue, May 15, 2018 at 09:48:11AM +0200, Federico Cabiddu wrote:

> Hi,
> rfc 3261 (the one and only) states at section16.7
> "
>          A proxy which receives a 503 (Service Unavailable) response
>          SHOULD NOT forward it upstream unless it can determine that any
>          subsequent requests it might proxy will also generate a 503.
>          In other words, forwarding a 503 means that the proxy knows it
>          cannot service any requests, not just the one for the Request-
>          URI in the request which generated the 503.  If the only
>          response that was received is a 503, the proxy SHOULD generate
>          a 500 response and forward that upstream.
> "
> So Kamailio behavior is absolutely legitimate. If you want to change it you
> have to use the following tm parameter: http://www.
> kamailio.org/docs/modules/devel/modules/tm.html#remap_503_500.

Oh yeah. How about that! (Re)learn something new every day. Cheers
Federico! :-)

Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) 
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

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