Hello, An end-to-end ACK should be sent to the Contact in the 200 OK. The actual network and transport-layer destination will differ due to the intermediate Record-Route hops.
In RFC parlance, this is known as the "remote target" of the dialog. The ACK is in substance an in-dialog request, so the routing would be the same as for a reinvite or a BYE: Record-Route hops are converted to Route headers and stripped off by intermediate proxies, but the request URI is set to the remote Contact URI and that is the final hop. -- Alex On Mon, Feb 11, 2019 at 01:48:06PM +1300, David Cunningham wrote: > Hello, > > Could someone please confirm the correct routing of an ACK? > A device receives the following 200 OK. Should the ACK it sends in response > be sent to the first Via address? I believe that sending it to the Contact > address is incorrect? If anyone happens to know the part of the RFC that > specifies this it would be very helpful. > Thank you in advance. > > SIP/2.0 200 OK > Via: SIP/2.0/TLS xx.xx.102.10:5061;rport=51582;branch=z9hG4bK85341894 > Record-Route: <sip:yy.yy.246.146;r2=on;lr=on> > Record-Route: <sip:yy.yy.246.146:5061;transport=tls;r2=on;lr=on> > From: Test <sip:111...@sip.example.com>;tag=Nf5GGRC3g6plN!8si1807E2D3ad0440e > To: <sip:222...@sip.example.com:5061>;tag=as448937d5 > Call-ID: 105176...@xx.xx.102.10 > CSeq: 5295 INVITE > Server: ES8 > Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO, > PUBLISH, MESSAGE > Supported: replaces, timer > Contact: <sip:222...@yy.yy.246.146:5070> > Content-Type: application/sdp > Content-Length: 337 > > -- > David Cunningham, Voisonics Limited > http://voisonics.com/ > USA: +1 213 221 1092 > New Zealand: +64 (0)28 2558 3782 > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors -- 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/ _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
