[asterisk-users] Use of "603 Declined"

[Alex Balashov]

Kristian,

Unfortunately, 603 Declined is frequently misused this way by service 
providers and SIP stacks.  It seems to be a catch-all epithet for some 
sort of miscellaneous call completion failure that cannot be categorised 
any other way, much like 503 Service Unavailable.

I agree 100% with this statement, and have taken this position for a 
long time:

On 01/28/2010 04:17 PM, Kristian Kielhofner wrote:

> "returned only if the client (Asterisk) knows that no other end point
> will answer the request"
>
>    That's a little presumptive of the Asterisk system, don't you think?
> ;)  While I don't have any better alternative responses I'm just
> bothered by the "global" nature of 6xx failures in the first place.

It's also problematic because a 3261-compliant SIP proxy or UAC is not 
going to attempt to reach the destination by alternate means (serial 
forking in the case of the proxy, or a new call leg in the case of the 
UA) because of this precise implication of 6xx-class final replies.

-- Alex

-- 
Alex Balashov - Principal
Evariste Systems LLC

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