On 04 Feb 2014, at 18:58, Alex Balashov <abalas...@evaristesys.com> wrote:
> On 02/04/2014 12:54 PM, Olle E. Johansson wrote: > >> And you assume a lot of things - that your invites are sent to the same >> server, which may not be the case. DNS lookups and load balancing/failover >> is done on a per transaction basis. > > In fairness, RFC 3578 does offer a fair bit of commentary on this caveat: > > However, having subsequent INVITEs routed in different ways brings > some problems as well. The first INVITE, for instance, might be > routed to a particular gateway, and a subsequent INVITE, to another. > The result is that both gateways generate an IAM. Since one of the > IAMs (or both) has an incomplete number, it would fail, having > already consumed PSTN resources. > > [...] > > Routing in SIP can be controlled by the administrator of the network. > Therefore, a gateway can be configured to generate SIP overlap > signalling in the way described below only if the SIP routing > infrastructure ensures that INVITEs will only reach one gateway. > When the routing infrastructure is not under the control of the > administrator of the gateway, the procedures of Section 2 have to be > used instead. > > And, while I agree that this is ridiculous and is in conflict with the basic > spirit of SIP, somehow 3578 did become an RFC... I am as puzzled by that as > you may be. :-) That's applying a strict route. IMS has some similar overrides too... Ouch. Regardless, it doesn't talk about overlapping INVITE transactions, just a series of INVITE transactions. /O _______________________________________________ SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
