Hi Christian, you are right, it is missing in the generated OPTIONS from nathelper. It needs to be added in the respective code part probably.
Cheers, Henning Westerholt -- Henning Westerholt - https://skalatan.de/blog/ Kamailio services - https://gilawa.com > -----Original Message----- > From: Christian Schnell via sr-users <sr-users@lists.kamailio.org> > Sent: Donnerstag, 23. November 2023 13:41 > To: sr-users@lists.kamailio.org > Cc: Christian Schnell <c...@rekoba.de> > Subject: [SR-Users] Max-Forwards header missing in OPTIONS keep-alive > messages > > Hello, > > in RFC 3261 (sec. 8.1.1.6) it states about the Max-Forwards header field: > > > A UAC MUST insert a Max-Forwards header field into each request it > originates with a value that SHOULD be 70. > > > > Source: https://datatracker.ietf.org/doc/html/rfc3261#section-8.1.1.6 > > When Kamailio sends its OPTIONS keep-alive requests (from the nathelper > module I believe), Max-Forwards is missing: > > > OPTIONS sip:al...@example.com:61266 SIP/2.0 > > Via: SIP/2.0/UDP aa.bb.cc.dd:5060;branch=z9hG4bK5124450 > > From: > > sip:pin...@sip.example.com;tag=uloc-6550aa14-7456-2461-6390f173- > 5fdb46 > > 67 > > To: sip:al...@example.com:61266 > > Call-ID: aba25282-2ca72be1-9d1f...@aa.bb.cc.dd > > CSeq: 1 OPTIONS > > Content-Length: 0 > > The user agent library I'm using (libre from baresip) rejects these requests > with > a "400 Bad Request" response, I looked at the sources and it denies these > requests because of the missing Max-Forwards header. > > Of course this suffices for the keep-alive logic because all that's needed is > any > traffic in both directions to keep both (potential) NATs open. However you > might agree that it does look a bit confusing at first, and the RFC is clear > about > that. > > So it's not a bug, but is this behavior intended? > > Thanks, also thanks for all the great work that has been put into Kamailio. > > Christian > > > __________________________________________________________ > Kamailio - Users Mailing List - Non Commercial Discussions To unsubscribe > send an email to sr-users-le...@lists.kamailio.org > Important: keep the mailing list in the recipients, do not reply only to the > sender! > Edit mailing list options or unsubscribe: __________________________________________________________ Kamailio - Users Mailing List - Non Commercial Discussions To unsubscribe send an email to sr-users-le...@lists.kamailio.org Important: keep the mailing list in the recipients, do not reply only to the sender! Edit mailing list options or unsubscribe:
