Re: [Sip-implementors] Question on Offer/Answer Model with SIP

2018-12-19 Thread Paul Kyzivat
Amarnath, Take a look at RFC6337 for an in-depth treatment of offer/answer issues and best practices. More below, consistent with what is in that rfc. On 12/19/18 12:28 AM, Amarnath Kanchivanam wrote: Hi, I have below call flow and would like to know the correct behavior. UAC

Re: [Sip-implementors] Appropriate back-off response for overly frequent registrations

2018-12-19 Thread Philipp Schöning
> There are a lot of good reasons of not using STUN but there are no good > reasons of not using STUN for UDP keep-alive. STUN keep-alive is extremely > easy to implement. It is possible to verify packet validity and it can be > used to detect local IP change. Do you know any implementation

Re: [Sip-implementors] Question on Offer/Answer Model with SIP

2018-12-19 Thread Richard Phernambucq
You can find an example for Call Hold in RFC5359 chapter 2.1. To take a call off hold the UA has to send a message with attribute a=sendrecv. In message F16 this attribute is omitted, so the default value of sendrecv is assumed (RFC4566 chapter 6). If the offer contains a=recvonly, as in your

Re: [Sip-implementors] Question on Offer/Answer Model with SIP

2018-12-19 Thread Amarnath Kanchivanam
Thanks All for your response. I did try to send Ack with "sendrecv" attribute, but still it doesn't work. Do we have any RFC describing call flow for various scenarios? Regards, Amarnath On Wed, Dec 19, 2018 at 2:08 PM Olle E. Johansson wrote: > > > > On 19 Dec 2018, at 09:28, Richard

Re: [Sip-implementors] Question on Offer/Answer Model with SIP

2018-12-19 Thread Olle E. Johansson
> On 19 Dec 2018, at 09:28, Richard Phernambucq > wrote: > > Hi Amarnath, > > A Re-Invite without SDP is called a late offer and isn't the same as resuming > a call that was placed on hold. > > If 'UAS' wanted to resume the call it should have sent an SDP body with > sendrecv attribute. I

Re: [Sip-implementors] Question on Offer/Answer Model with SIP

2018-12-19 Thread Richard Phernambucq
Hi Amarnath, A Re-Invite without SDP is called a late offer and isn't the same as resuming a call that was placed on hold. If 'UAS' wanted to resume the call it should have sent an SDP body with sendrecv attribute. Best regards, Richard On 19-12-2018 06:28, Amarnath Kanchivanam wrote: