Voice over IP Cisco - SIP disposition after 488 to T.38

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Author SIP disposition after 488 to T.38
roy

2007-06-28, 1:11 am

Hi List,

Here's a setup and packet capture flow:

SIP box Cisco
[a@b.com] [x@y.com]
INVITE x@y.com --------->
<--------- 100 TRYING
<--------- 183 Session Progress
<--------- 200 OK
ACK x@y.com --------->
<--------- re-INVITE a@b.com to t.38
488 --------->
<--------- ACK
....
....

Given that only available codec of g.729 at Asterisk side, what messages
are to be expected after the T.38 re-invite has been made and was
rejected with 488?

Thanks,

Roy
Fedorov, Konstantin

2007-06-28, 1:11 pm

Hi,

Can you provide full capture of SIP signaling.
Because now its difficult to say what is the reason jf 488 message.

488 message mean - Not applicable here. So SIP box doesn't like
re-invite

-----------------------
Sincerely Yours,
Konstantin Fedorov
-----Original Message-----
From: cisco-voip-bounces@puck.nether.net
[mailto:cisco-voip-bounces@puck.nether.net] On Behalf Of roy
Sent: Thursday, June 28, 2007 8:36 AM
To: cisco-voip
Subject: [cisco-voip] SIP disposition after 488 to T.38

Hi List,

Here's a setup and packet capture flow:

SIP box Cisco
[a@b.com] [x@y.com]
INVITE x@y.com --------->
<--------- 100 TRYING
<--------- 183 Session Progress
<--------- 200 OK
ACK x@y.com --------->
<--------- re-INVITE a@b.com to t.38
488 --------->
<--------- ACK
....
....

Given that only available codec of g.729 at Asterisk side, what messages
are to be expected after the T.38 re-invite has been made and was
rejected with 488?

Thanks,

Roy

________________________________________
_______
cisco-voip mailing list
cisco-voip@puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-voip
roy

2007-06-29, 1:11 am

Hi Konstantin,

When a call from the sip box hits an IVR/fax, the cisco box detects the
SIT and tries to negotiate t38. 488 has been sent since the SIP box has
disabled t38. There would have been a fall-back if g711 is available,
but, due to some constraints, 711 isn't available. Hope I'm not missing
something here.

Thanks,

Roy

On Thu, 2007-06-28 at 18:20 +0400, Fedorov, Konstantin wrote:
> Hi,
>
> Can you provide full capture of SIP signaling.
> Because now its difficult to say what is the reason jf 488 message.
>
> 488 message mean - Not applicable here. So SIP box doesn't like
> re-invite
>
> -----------------------
> Sincerely Yours,
> Konstantin Fedorov
> -----Original Message-----
> From: cisco-voip-bounces@puck.nether.net
> [mailto:cisco-voip-bounces@puck.nether.net] On Behalf Of roy
> Sent: Thursday, June 28, 2007 8:36 AM
> To: cisco-voip
> Subject: [cisco-voip] SIP disposition after 488 to T.38
>
> Hi List,
>
> Here's a setup and packet capture flow:
>
> SIP box Cisco
> [a@b.com] [x@y.com]
> INVITE x@y.com --------->
> <--------- 100 TRYING
> <--------- 183 Session Progress
> <--------- 200 OK
> ACK x@y.com --------->
> <--------- re-INVITE a@b.com to t.38
> 488 --------->
> <--------- ACK
> ...
> ...
>
> Given that only available codec of g.729 at Asterisk side, what messages
> are to be expected after the T.38 re-invite has been made and was
> rejected with 488?
>
> Thanks,
>
> Roy
>
> ________________________________________
_______
> cisco-voip mailing list
> cisco-voip@puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-voip
>
>

Fedorov, Konstantin

2007-06-29, 7:11 am

Hi Roy,

Ok, I understand.

I think its depends, which method of fax sending you use.

1/ If fax machine auto answer call, then after no more sip messages can
be.

2/ If before fax sending you open voice stream, I mean you talk with
person
Which must receive fax, then after fail attempt its possible to send
again re-invite.

-----------------------
Sincerely Yours,
Konstantin Fedorov

-----Original Message-----
From: roy [mailto:bandwidth.user@gmail.com]
Sent: Friday, June 29, 2007 6:55 AM
To: Fedorov, Konstantin
Cc: cisco-voip
Subject: RE: [cisco-voip] SIP disposition after 488 to T.38

Hi Konstantin,

When a call from the sip box hits an IVR/fax, the cisco box detects the
SIT and tries to negotiate t38. 488 has been sent since the SIP box has
disabled t38. There would have been a fall-back if g711 is available,
but, due to some constraints, 711 isn't available. Hope I'm not missing
something here.

Thanks,

Roy

On Thu, 2007-06-28 at 18:20 +0400, Fedorov, Konstantin wrote:
> Hi,
>
> Can you provide full capture of SIP signaling.
> Because now its difficult to say what is the reason jf 488 message.
>
> 488 message mean - Not applicable here. So SIP box doesn't like
> re-invite
>
> -----------------------
> Sincerely Yours,
> Konstantin Fedorov
> -----Original Message-----
> From: cisco-voip-bounces@puck.nether.net
> [mailto:cisco-voip-bounces@puck.nether.net] On Behalf Of roy
> Sent: Thursday, June 28, 2007 8:36 AM
> To: cisco-voip
> Subject: [cisco-voip] SIP disposition after 488 to T.38
>
> Hi List,
>
> Here's a setup and packet capture flow:
>
> SIP box Cisco
> [a@b.com] [x@y.com]
> INVITE x@y.com --------->
> <--------- 100 TRYING
> <--------- 183 Session Progress
> <--------- 200 OK
> ACK x@y.com --------->
> <--------- re-INVITE a@b.com to t.38
> 488 --------->
> <--------- ACK
> ...
> ...
>
> Given that only available codec of g.729 at Asterisk side, what

messages
> are to be expected after the T.38 re-invite has been made and was
> rejected with 488?
>
> Thanks,
>
> Roy
>
> ________________________________________
_______
> cisco-voip mailing list
> cisco-voip@puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-voip
>
>

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