Hello, This stateless call flow is smooth in 5.1 branch, at least 5.1.7 but in 5.2.1 already broken IIRC. Some time ago I wrote about this very same issue
10.02.2020, 18:39, "Daniel-Constantin Mierla" <[email protected]>: > In such case, because the proxy is doing stateless forwarding, there is > no transaction. I guess the solution right now is to use tm for relaying > - is any concern of doing that? > > If someone wants to look at generating same via branch, I am fine with > it, eventually controlled by a parameter if the code change is > significant, to be able to switch to current mode if unexpected side > effects pop up. > > One more note in this case: I expect it would be required to generate > different tag for 200ok ACK, so it is matched as different transaction > by next hop, not sure if there is any easy way to discover the type of > ACK in a stateless proxy. > > I am not sure I remember correctly, but in some discussions I think it > was suggested to just reuse the branch value of incoming top Via when > doing stateless forwarding. > > Cheers, > Daniel > > On 10.02.20 16:26, Sebastian Damm wrote: >> We use 5.2 on the affected systems. >> >> On Mon, Feb 10, 2020 at 4:15 PM Serge S. Yuriev <[email protected]> wrote: >>> Hi >>> >>> I believe you are using 5.2 or 5.3 series? This tend to work properly on >>> 5.1 series >>> >>> 10.02.2020, 18:10, "Sebastian Damm" <[email protected]>: >>>> Hi, >>>> >>>> actually, our only problem is handling negative replies. The ACK >>>> belongs to the same transaction and therefore has to carry the same >>>> Via branch ID. >>>> >>>> Sebastian >>>> >>>> On Mon, Feb 10, 2020 at 3:50 PM Yuriy Gorlichenko <[email protected]> >>>> wrote: >>>>> ACK for successull response is a new transaction. It has to be >>>>> different. May be it is better to point provider to this? >>>>> >>>>> On Mon, 10 Feb 2020, 14:26 Sebastian Damm, <[email protected]> wrote: >>>>>> Hi, >>>>>> >>>>>> I stumbled upon an interop problem with a carrier. We have the >>>>>> following scenario: >>>>>> >>>>>> Gateway --> Loadbalancer --> Carrier >>>>>> >>>>>> The loadbalancer generates a Via header for each request. But since it >>>>>> is stateless, the Via tag is generated for each request. As a >>>>>> consequence, the Via tag in the ACK differs from the one in the >>>>>> INVITE. And one carrier doesn't handle those ACKs if the Via tag >>>>>> differs. >>>>>> >>>>>> Is there a way to force the creation of a "deterministic" Via branch >>>>>> tag? For example, building it from a hash over call-id and from-tag or >>>>>> something like that? -- wbr, Serge _______________________________________________ Kamailio (SER) - Users Mailing List [email protected] https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
