Subject: [Megaco] Ambiguous digit map match in Megaco and MGCP

From: Raphael Tryster <[email-masked]>
Date: Mon, 10 Nov 2003 17:11:04 +0200

If I interpret the standards correctly, Megaco and MGCP seem to require
different behaviour on an ambiguous digit map match.  For example (using
MGCP syntax:

D: (0|[1-9]xxx|9|[*,#]xx[*,#]|*#xx[*,#]|[2-4]x#|[2-9]#|[2-4]xT|[2-9]T) 

Suppose the subscriber dials 9.  In Megaco, the MG waits for a few seconds
to see if the 9 will be followed by 3 digits or # or timeout.  In MGCP, the
MG is expected to NTFY the digit 9 immediately, and the alternatives of
9xxx, 9# and 9T are meaningless.

Am I correct about this difference between the protocols, and if so, why
does MGCP allow impossible alternatives?

Raphael Tryster

---

From: "Kevin Boyle" <[email-masked]>
Date: Mon, 10 Nov 2003 10:36:20 -0500

When writing digitmaps, some attention must be paid to whether the digitmap
will be operating on a shortest possible match, or longest possible match.
This will certainly have impact upon how the digitmap should look.
 
I, personally, have problems with the longest possible match idea, because
it leads to unnecessary delay for shorter digit patterns, and requires more
complexity in the digitmap.  H.248.16 outlines digit collection packages
that allow shortest possible match behavior, as well as some other key
functionality for digit collection.
 
Kevin

  _____  

From: Raphael Tryster [mailto:[email-masked]] 
Sent: Monday, November 10, 2003 10:11 AM
To: 'MGCP Discussion List'; [email-masked]
Subject: [Megaco] Ambiguous digit map match in Megaco and MGCP

Raphael Tryster 

_______________________________________________
Megaco mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/megaco

---

From: "Kevin Boyle" <[email-masked]>
Date: Mon, 10 Nov 2003 10:36:20 -0500

Kevin

  _____  

Raphael Tryster