[Sip-implementors] m lines after after SDP offer/answer exchange failure

2015-09-15 Thread Andrea Rizzi
Let’sassume a session is in place, established through an offer/answer exchange witha single media stream (i.e. a single m line). Then, theUAC A sends a reINVITE containing an SDP offer having two m lines, and theoffer is rejected by the UAS B (let say with a 488). Thequestion is about the numb

Re: [Sip-implementors] Two provisional responses in one dialog: 180 Ringing and 183 Session Progress

2015-09-01 Thread Andrea Rizzi
Hi all, RFC3960, gateway model, says basically: once you receive a 180 ringing plays a local ringback UNLESS you are actually already receiving a stream. This should mean that in case an RTP stream is flowing, you have to "ignore" the 180 and continue playing the stream. Note that in field scenari

Re: [Sip-implementors] M line ordering in Re-invite SDP for Interdomain fax

2012-05-11 Thread Andrea Rizzi
I basically agree (as almost usually) with Paul. From the protocol compliancy point of view, adding a new m line for the T.38 stream (regardless it is the first or the second one, both options are allowed in my interpretation of RFC3264) is allowed as well as replacing the first one, formerly audio

Re: [Sip-implementors] M line ordering in Re-invite SDP for Interdomain fax

2012-05-11 Thread Andrea Rizzi
I basically agree (as almost usually) with Paul. From the protocol compliancy point of view, adding a new m line for the T.38 stream (regardless it is the first or the second one, both options are allowed in my interpretation of RFC3264) is allowed as well as replacing the first one, formerly audio

Re: [Sip-implementors] T.38 handling in SIP

2009-07-21 Thread Andrea Rizzi
There's no a standard way to renegotiate the T.38 media. Usually it is the called party that issues the reINVITE, but there are implementations where the reINVITE is sent by the calling party once the CNG is detected (of course in the most common scenario where the calling party is the one sending

Re: [Sip-implementors] in-active in answer with sendonly in offer

2009-02-23 Thread Andrea Rizzi
Answering with inactive may also be used to save bandwidth (in addition to DSP resources as already mentioned) in the call hold scenario. Inactive will force the holding party to stop sending media, leaving the held party to generate proper notification to the user (a message, a special hold tone o

Re: [Sip-implementors] T38 FAX flows problem?

2009-02-10 Thread Andrea Rizzi
According to your call flow, it appears Broadsoft server acts in a proprietary way that doesn't fit the usual switchover to T.38. Here my opinions: Problem 1 The parameters you mention (and maybe you expect) are all optional but T38FaxRateManagement, which is the only mandatory parameter. Btw, fro

Re: [Sip-implementors] user=phone usage in SIP trunking gateways

2009-01-21 Thread Andrea Rizzi
Sorry, I reported the wrong RFC number, the right one is 3398 "SIP-ISUP mapping". I beg your pardon Andrea -Original Message- From: Paul Kyzivat [mailto:pkyzi...@cisco.com] Sent: mercoledì 21 gennaio 2009 17.29 To: Andrea Rizzi Cc: sip-implementors@lists.cs.columbia.edu S

[Sip-implementors] user=phone usage in SIP trunking gateways

2009-01-21 Thread Andrea Rizzi
I'm coming back to an old question as it appears to me RFCs says differently about. Quoting an old answers from Paul: "If user=phone is present, then the syntax of the user part must conform with the TEL URI syntax as defined in RFC 3966. That syntax says that the number must start wi

Re: [Sip-implementors] Clarification Question on UPDATE RFC3311

2008-10-31 Thread Andrea Rizzi
Brett, Could you please clarify why an unreliable provisional response doesn't complete an offer/answer? IMO, when a UAC send an offer on the Invite, the SDP included in the first provisional response closes the offer/answer exchange, regardless it is reliable or not. The UAS, of course, cannot be

Re: [Sip-implementors] RFC 2833 Telephone-Event RTP Payload

2008-09-29 Thread Andrea Rizzi
IMO, dynamic payload "negotiation" follows the same rules for the audio codecs. From my point of view, there's no a real negotiation (let say H.323-like) in RFC3264 (i.e. the RFC you would refer to), unless you change some SHOULD or RECOMMENDED in Section 6.1 to MUST. Then, despite suggested, it is

Re: [Sip-implementors] Query on UAC Behaviour for 180 Ringing followed by 183 with SDP

2008-02-28 Thread Andrea Rizzi
The title says the opposite of the mail's contents, btw: RFC3960, gateway model gives guidelines about the, let's say, "correct" behavior. The main rule says more or less "media has always the precedence". About the scenario you mentioned in the text, i.e. 183/SDP and then 180 (no SDP I assume) you

Re: [Sip-implementors] Is valid a "183 Session Progress" with

2008-01-18 Thread Andrea Rizzi
Regarding " The best recommendation I have seen (don't remember where it was written) is that you should render a local ringback if you get a 180 *and* are not receiving media" The behavior is suggested by RFC 3960, gateway model. I basically agree with Paul. Any RFC will say what the client h

Re: [Sip-implementors] Sip-implementors Digest, Vol 56, Issue 28

2007-11-28 Thread Andrea Rizzi
EFER method. Andrea -Original Message- From: Vikram Chhibber [mailto:[EMAIL PROTECTED] Sent: mercoledì 28 novembre 2007 19.42 To: Andrea Rizzi Cc: sip-implementors@lists.cs.columbia.edu; [EMAIL PROTECTED] Subject: Re: [Sip-implementors] Sip-implementors Digest, Vol 56, Issue 28 Andrea, I w

Re: [Sip-implementors] Sip-implementors Digest, Vol 56, Issue 28

2007-11-28 Thread Andrea Rizzi
Sanjay, Below you said: - If user2 disconnects before transfer is complete, user1 can choose not to send final Notify once the outcome of transfer is known. Or even if it does, since user2 does not have sense of the call leg with user1, it will send 481 response to that Notify. - In case

Re: [Sip-implementors] Blind transfer using REFER

2007-11-27 Thread Andrea Rizzi
IMO, when User 2 disconnects after transferring the call, from the user perspective it leaves the former calls, while it is not involved at all in the transferred call. From the signaling perspective, when disconnecting (after REFERring the first call) it sends a BYE closing the first call. The tra

Re: [Sip-implementors] Error in incoming req uri, what to do?

2007-11-15 Thread Andrea Rizzi
Attila, The '*' char shall not be escaped IMO, this is allowed by RFC 2396 in URI syntax. Have you references saying the '*' should be escaped? Andrea -- Message: 3 Date: Wed, 14 Nov 2007 15:11:41 -0600 From: Robert Sparks <[EMAIL PROTECTED]> Subject: Re: [Sip-imple

Re: [Sip-implementors] Call hold and a = inactive

2007-06-27 Thread Andrea Rizzi
Paul, Just a note about your answer . SIP has no mechanism that tells the other party that the HOLD feature has been invoked. The sendonly/recvonly/inactive mechanism can be *used* when HOLD has been invoked locally, to optimize the use of the media path. But the same mechanisms are a

Re: [Sip-implementors] Call hold and a = inactive

2007-06-27 Thread Andrea Rizzi
Just read section 6.1 . Should the attribute be missing in the answer, it implicitly means sendrecv, i.e. it is forbidden! Andrea -Original Message- From: David Benoit [mailto:[EMAIL PROTECTED] Sent: mercoledì 27 giugno 2007 16.21 To: Andrea Rizzi Cc: 'varun'; sip-im

Re: [Sip-implementors] Call hold and a = inactive

2007-06-27 Thread Andrea Rizzi
Option 3 is forbidden by RFC3264! Andrea -Original Message- From: David Benoit [mailto:[EMAIL PROTECTED] Sent: mercoledì 27 giugno 2007 15.20 To: varun Cc: Andrea Rizzi; sip-implementors@lists.cs.columbia.edu Subject: Re: [Sip-implementors] Call hold and a = inactive Hi, The exchange

Re: [Sip-implementors] Call hold and a = inactive

2007-06-27 Thread Andrea Rizzi
There are no violations at all in responding with inactive, and as you mentioned this will suspend any media, as the holding procedure is definitively a new offer/answer exchange. Actually, in my opinion, this would be the preferred way to implement the call hold service, to save bandwidth, of cou