Subject: [Sipping] Re: mike pierce issue summary (item #2)

From: [email-masked]
Date: Fri, 16 Aug 2002 15:31:49 EDT

In a message dated 8/15/02 5:11:13 PM Eastern Daylight Time, 
[email-masked] writes:

> [MAP] 2. If the SIP user has the ability to send any response code, which 
gets 
> translated to a specific Cause code, they could do harm by misleading the 
> originating network. For example, a Cause code of 25, Exchange routing 
error, 
> could be returned, causing the originating switch to not route to this 
number 
> again or to any with the same routing digits. In the ISDN world, this was 
> prevented since the user could not send this Cause value.
> 

[JP] Can anyone provide some corroboration (a textual reference would be nice)
for that cause code 25 behavior in ITU-T standards?

If there is a good reason to think this is the case, we'll change that
particular mapping so that cause 25 is not sent.

[MAP] Sorry, I did not include more detail for the example I gave.

Q.764 states in Section 2.1.7.1 that "an originating exchange receiving a 
Release message with cause #25 (exchange routing error) shall notify the 
Management system." I believe it is generally understood that the purpose of 
such a notification is to allow the Management system to take action to 
prevent this bad routing from occurring again.

I don't think you should remove the mapping for the cause 25 since it can be 
used in the correct way by trusted gateways or proxies.

Mike Pierce
Artel