Subject: Destination Status Unknown Message

From: "Vats, Umesh" <[email-masked]>
Date: Wed, 12 Dec 2001 09:50:26 -0800

Hi  

In section 3.8.1 (Error messages) in the draft 10 of M3UA,
following paragraph exists :

 The "Destination Status Unknown" Error MAY be sent if a DAUD is 
received at an SG enquiring of the availability/congestion status of 
a destination, and the SG does not wish to provide the status (e.g., 
the sender is not authorized to know the status).  For this error, the 
invalid or unauthorized Point Code(s) MUST be included along with the 
Network Appearance and/or Routing Context associated with the Point 
Code(s).

My query is, when will the sender be not authorised to know the pointcode
status ? Is this a realistic case ?

If the answer to above question is yes, then if the same unauthorise sender
sends a regular DATA message, then should SGP drop it or route it ?
If SGP is routing the DATA message properly, then destination status may
become indirectly known to the unauthorised user. 

thanks
Umesh

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From: "Brian F. G. Bidulock" <[email-masked]>
Date: Wed, 12 Dec 2001 15:18:54 -0600

Umesh,

Vats, Umesh wrote:                            (Wed, 12 Dec 2001 09:50:26)
> status ? Is this a realistic case ?

Yes.  It supports gateway screening at the SG.

> become indirectly known to the unauthorised user. 

Normally an SG performing screening would silently discard the message.  As
the SG has never sent a DAVA to the AS, the choices are silent discard or
responsive DUNA.  The DUNA sent responsively does not indicate the status
of the remote destination: it indicates that the destination is unavailable
from the concerned AS.

--brian

> 
> thanks
> Umesh
> 
> 
> 
> 
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-- 
Brian F. G. Bidulock
[email-masked]
http://www.openss7.org/

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