Hi, 1. Please note that SIP is not limited to telephony application. For instance, user tries to register SIP address, mail address and phone number as a contact address in one REGISTER message. In addition, it can not be used to register multiple devices, only multiple identities of one device.
2. There are no further messages to be send to UA which is associated with REGISTER. With SUBSCRIBE, that is the not the case. NOTIFY will be send in reference to SUBSCRIBE that created the dialog. 3. Since it is optional and not sent in the REGISTER request, I would like to see registrar to simply return the present bindings. However not surprise for me if it's been rejected with 400 Bad Request and can be seen in many practical implementations. 4. One of our community friend has excellently described here; https://abhishekchattopadhyay.wordpress.com/2010/09/21/why-ack-is-a-separate-transaction-for-invite-with-a-successful-200-ok%C2%A0response%C2%A0/ 5. Will see other to respond on logical reason behind it. Thanks Vivek Batra On Wed, Dec 30, 2015 at 12:02 PM, Karthik.v <karthik...@plintron.com> wrote: > Hi all, > > I have some list of queries on sip , > > > > 1) Please state a real time scenario where multiple contact headers will be > present in a REGISTER request ? > > 2) Why Register does not establish a dialog & subscribe establish a dialog > ? > 3) As per rfc 3261, it has been said that contact header is not mandatory > in > REGISTER request but without contact header in REGISTER request our app is > generating 400 Bad Request, whether it is right or wrong ? > > 4) Why ACK should be considered as a transaction ? > > 5) What's the logical reason behind the "The Contact header field MUST > contain exactly one SIP > > or SIPS URI in any request that can result in the establishment of a > dialog" ? > > > > > > Thanks & Regards, > > Karthik V > > > > > > _______________________________________________ > Sip-implementors mailing list > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > -- Best Regards, Vivek Batra _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
