A new standard is in progress for just this question: <https://datatracker.ietf.org/doc/draft-ietf-ecrit-psap-callback/>
It uses the Priority header to mark callbacks: Priority: psap-callback On Oct 25, 2013, at 12:21 PM, Manolis Katsidoniotis <mano...@gmail.com> wrote: > Hi > many thanks for the answer :) > > Any idea as to how I can get the Callback indication in there? > > Does the sip URI in that last one signify that it is a call back to an > emergency call performed a few seconds earlier? > > Route: <sip:+49xxxxxxxxxx@172.24.0.3:5060;user=phone;lr> > > ... or is perhaps Emcy Callback shown some other way in the INVITE? > > thanks > Manolis > > > On Fri, Oct 25, 2013 at 3:27 AM, Despina Kitsou <kalist...@hotmail.com>wrote: > >> Hello, >> >> >> A typical Route header will look like this: >> >> >> From RFC3261: >> >> Route= "Route" >> HCOLON<http://www.in2eps.com/fo-abnf/tk-fo-abnf-siprules.html#hcolon> >> route-param >> *(COMMA<http://www.in2eps.com/fo-abnf/tk-fo-abnf-siprules.html#delim> >> route-param) >> >> ; example: >> ; Route: <sip:ss1.atlanta.example.com;lr>, >> ; <sip:ss2.biloxi.example.com;lr> >> >> Other examples: >> >> Route: <sip:scscf1.ims.m-online.net:5090;lr;> >> >> Route: <sip:scscf1.ims.m-online.net:5090;lr>, >> <sip:scscf2.ims.m-online.net:5090;lr> >> >> Route: <sip:+49xxxxxxxxxx@172.24.0.3:5060;user=phone;lr> >> >> Also here defined the sip parameters: >> http://www.iana.org/assignments/sip-parameters/sip-parameters.xhtml >> >> br, >> Despina >> >> >> >>> Date: Fri, 25 Oct 2013 00:16:37 -0500 >>> From: mano...@gmail.com >>> To: sip-implementors@lists.cs.columbia.edu >>> Subject: [Sip-implementors] CallBack to emergency call >> >>> >>> Hello folks >>> >>> I have an IMS case where a terminating point for emergency calls (PSAP) >> is >>> performing callback to the user that placed the original emergency call. >>> >>> It appears that the top most Route header in CallBack INVITE needs to >> have >>> a Callback timer indication. >>> >>> Does anyone happen to have an example of how the Route header should look >>> like? >>> >>> (the flow below is just a quick indication, several packets are missing) >>> >>> UE1 IMS SBC <==> PSAP >>> | --------> | | >>> | INVITE 911 | | >>> | | | >>> | | --------> | >>> | | INVITE 911 | >>> | | | >>> | | <-------- | >>> | | 200OK | >>> | | | >>> | <-------- | | >>> | 200OK | | >>> | | | >>> | --------> | | >>> | BYE | | >>> | | --------> | >>> | | BYE | >>> | | <-------- | >>> | | 200OK | >>> | <-------- | | >>> | 200OK | | >>> | | | >>> ====================================== >>> Callback >>> ====================================== >>> | | | >>> | | <-------- | >>> | | INVITE | >>> | | (CallBack) | >>> | | | >>> | <-------- | | >>> | INVITE | | >>> | (CallBack) | | >>> | | | >>> | --------> | | >>> | 200OK | | >>> | | | >>> | | --------> | >>> | | 200OK | >>> | | | >>> | --------> | | >>> | BYE | | >>> | | | >>> | | --------> | >>> | | BYE | >>> | | | >>> | | <-------- | >>> | | 200OK | >>> | | | >>> | <-------- | | >>> | 200OK | | >>> >>> thanks in advance >>> Manolis >>> _______________________________________________ >>> Sip-implementors mailing list >>> Sip-implementors@lists.cs.columbia.edu >>> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
