On 9/19/2010 12:38 AM, anand madhab wrote:
> Hi,
>
> No, my query is, I have sent INVITE without m line but with sdp , and i have
> received response 200 ok also with sdp but without m line, so what should
> caller do reject the call or what ? And isn't it like call is on hold
> because there is on media ?
> Or
> Callee should have respond with 415 unsupported media ?
This question is still confusing. IIUC, you are saying that the UAC has
sent an INVITE with SDP without any m-lines.
If so, then it has given the UAS few options.
The UAS can answer with an SDP containing no m-lines, and thus establish
a connection with no media.
OR, the UAS can return an error, such as 415, if it doesn't want to
participate in a call with no media.
I think you will find many/most audio UAs will probably return 415 or
some other error. It would be more forgiving of them to accept the call
and just treat it as if on hold for whatever media they have.
Its really out of the hands of the UAC. It is the one that made the
offer with no media. There is no reason for it to send a BYE when the
UAS responds in the only way it can.
The problem with a connection without any media is: what happens next?
As long as it stays in that state the connection is largely useless. One
side or the other will need to do something - probably send a reINVITE
with a new offer that *does* include one or more m-lines.
But which side should do this? Either side could. I'm thinking that the
UAS, if it didn't already reject the call, would immediately send a
reINVITE with its default offer. If it can't get some media accepted,
then it will probably reject the call.
Of course the UAC could also immediate send another offer with media.
But if it wanted to do that, presumably it would have already done so.
The bottom line is that when you send an initial INVITE, you should
offer all the media you are prepared to use for the call, even ones you
want to start on hold. Or else you should send an INVITE without any
offer. There is no real benefit to hiding media you intend to use.
Thanks,
Paul
> On Fri, Sep 17, 2010 at 10:22 PM, Pavesi, Valdemar (NSN - US/Irving)<
> valdemar.pav...@nsn.com> wrote:
>
>> Do you want put on hold/resume ?
>> Or
>>
>> Do you want send a negative test without sdp-m-parameter. ?
>>
>>
>>
>> -----Original Message-----
>> From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:
>> sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of ext Tom
>> Kristensen
>> Sent: Friday, September 17, 2010 10:18 AM
>> To: anand madhab
>> Cc: Tom Kristensen; Sip-implementors@lists.cs.columbia.edu
>> Subject: Re: [Sip-implementors] sdp missing m line
>>
>> On 17 September 2010 13:46, anand madhab<anandmad...@gmail.com> wrote:
>>> Hi,
>>>
>>> I have a query.
>>> If m line is missing in invite request and 180, 200 response then what
>>> will be senario ?
>>> I dont understand the case, I mean i want to make a call with initially
>>> putting a person in hold ? please explain
>>> does caller need to reject the call
>>
>> I don't understand your case either! Please, elaborate and add more
>> details for us to understand what you mean.
>>
>> -- Tom
>>
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>
>
>
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