Subject: Re: [Sip] INFO method used for ISUP to SIP IW

From: [email-masked]
Date: Thu, 7 Jul 2005 10:36:08 EDT

In a message dated 7/7/2005 3:13:35 AM Eastern Daylight Time, 
[email-masked] writes:

> Yes. Q.1912.5 says that certain ISUP messages, in certain situations, are 
> encapsulated and carried in SIP 18x responses.
> 

Q.1912.5 doesn't say much about INFO at all. The only reference is explaining 
how "transparent" messages how encapsulated, and it says they are carried in 
the following:

a)  183 Session Progress provisional response if this is sent by the I-IWU in 
the backward direction before a confirmed dialog is established.
b)  INFO message in all other cases. 

This means that INFO is only used after a confirmed dialog, not before, at 
least in the backward direction. Q.1912.5 doesn't really describe the use of 
INFO in the forward direction, but it must be allowed, since it lists ISUP 
messages like Facility Request and User-to-User Information that can go in that 
direction.

Mike Pierce
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---

From: xupeili <[email-masked]>
Date: Fri, 08 Jul 2005 10:19:17 +0800

Hi, 

                This is my understanding of Q.1912.5 principle : 

                 Q.1912.5 will not re-define the general principle of when
INFO can be sent. This should be under the IETF SIP umbrella. 

                 As our discussion these days, INFO should be sent in both
direction after dialog(including early and confirm state ) is established.

                 Q.1912.5 does have rule on how, when and where to
encapsulate ISUP message under the SIP principle.

                 Q.1912.5 just recommend that It is better to facilitate 18x
to encapsulate backward ISUP messages before dialog is confirmed.   

                 All other case may include  (1) forward ISUP messages
before dialog is confirmed  ,(2) other forward or backward messages after
dialog is confirmed.

                 Just as chister mentioned: the final issue may go to
whether to encapsulate backword ISUP message befor dialog is confirmed in
1xx or INFO. 

                 For those messages with match meaning (180-ACM/CPG,
183-ACM/CPG) , the rule is clearly defined in Q.1912.5. 

                 For those ISUP message just need transparently sent and
without meaning-matching messages in SIP like INF/INR. 

                 18x and INFO may both suitable.  From the implementation
point of view, it`s better for SIP-ISUP IWU to support both.

          Best reguards!

          Peili Xu

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
[email-masked]
Sent: Thursday, July 07, 2005 10:36 PM
To: [email-masked]; [email-masked];
[email-masked]; [email-masked]; [email-masked];
[email-masked]
Subject: Re: [Sip] INFO method used for ISUP to SIP IW

Q.1912.5 doesn't say much about INFO at all. The only reference is
explaining how "transparent" messages how encapsulated, and it says they are
carried in the following:

This means that INFO is only used after a confirmed dialog, not before, at
least in the backward direction. Q.1912.5 doesn't really describe the use of
INFO in the forward direction, but it must be allowed, since it lists ISUP
messages like Facility Request and User-to-User Information that can go in
that direction.

Mike Pierce