cruzccl
commented
6 years ago Hi @ralonsom,
SIP routing defined in RFC 3261 is quite complex, but related to the Record-Route/Route headers, it could be summarized (and simplified) as:
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Initial request from UAC do not normally contain any of them.
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Traversed proxies may add Record-Route if the want to stay on the signalling path until the end of the dialog.
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Destination UAS must include all the Record-Route in replies so that both UAC and UAS have the same route set for next transations.
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Next in-dialog transaction must add as many Route headers as Record-Routes on the initial route sets, so that messages can be loose routed and traverse all the wanted proxies.
Although UAC behaviour described in 8.1 even recommends adding a Route in some initial requests, discarding this Routes is considered a good practise to avoid being used as an open relay (read this). In fact, removing them it is included in Kamailio's default configuration file.
But opensips doesn't remove them, it exits (see here).
You could try modifying that logic and removing Routes instead of exiting (as Kamailio's default config file does).
Regards,
Some models of phones or PBXs launch the first registration with "Route:". if the route is Route:domain , sbc answers "403 Preload Route denied". if the route is Route:IP the registry works correctly.