Subject: FW: [Sigtran] M2PA Last Call Comment

From: Schwarzbauer Hanns Juergen <[email-masked]>
Date: Mon, 14 Jul 2003 10:31:54 +0200

resend, because "sigtran list" wasn't included

-----Original Message-----
From: Schwarzbauer Hanns Juergen 
Sent: Monday, July 14, 2003 8:46 AM
To: [email-masked]'
Subject: RE: [Sigtran] M2PA Last Call Comment

Brian,

I don't understand your second point. There is an MTP L3 between the TDM and the IP side, so both sides are decoupled. Thus I can't agree with this point.

greetings

HannsJuergen

> -----Original Message-----
> From: Brian F. G. Bidulock [mailto:[email-masked]]
> Sent: Saturday, July 12, 2003 7:04 AM
> To: [email-masked]'
> Subject: [Sigtran] M2PA Last Call Comment
> 
> 
>   The proving period MAY be omitted if this is allowed by the 
> applicable
>   MTP2 standard (e. g., [Q.2210]).
> 
> The reference should be Q.2140.
> 
> It should also be noted that the same approach MUST be 
> followed on both sides
> the link.  Otherwise, one side following Q.703 will have T3 
> timer expire
> waiting for PROVING-NORMAL from the side foregoing proving.
> 
> --brian
> 
> -- 
> Brian F. G. Bidulock
> [email-masked]
> http://www.openss7.org/
> 
> _______________________________________________
> Sigtran mailing list
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---

From: "Brian F. G. Bidulock" <[email-masked]>
Date: Mon, 14 Jul 2003 03:40:15 -0600

Hanns Juergen,

Consider that one side follows Q.703 and requires proving while the
other side follows Q.2140 and foregoes proving.  The following will
occur:

    ___________________________________________________________________
   |                                                                   |
   |                Q.2140                      Q.703                  |
   |                                                                   |
   |        OUT-OF-SERVICE  ----------------->                         |
   |                        <-----------------  OUT-OF-SERVICE         |
   |                :start                                             |
   |             ALIGNMENT  ----------------->                         |
   |                                            :start                 |
   |                        <-----------------  ALIGNMENT              |
   |                 READY  ----------------->                         |
   |                        <-----------------  PROVING-NORMAL         |
   |                              !                                    |
   |                              !  T3         1.0 <= T3 <= 1.5       |
   |                              !                                    |
   |                        <-----------------  OUT-OF-SERVICE         |
   |                                                                   |
   |___________________________________________________________________|

Note that the Q.703 side must ignore the READY and await a
PROVING-NORMAL or PROVING-EMERGENCY (See Q.781 test case 2.3) and will
time out (See Q.781 test case 1.3).

Therefore unless both sides follow the Q.2140 procedures it will be
impossible to forego proving and successfuly align the link.

The issue has little to do with MTP Level 3.  It is solely an MTP Level
2 compatibility issue, speaks to interoperability, and the keyword MUST
should be used.  So,

  The proving period MAY be ommitted if this is allowed by the
  applicable standard (e.g., [Q.2140]); however, the same standard MUST
  be followed on both sides of the M2PA link.

Does that clear things up for you?

--brian

Schwarzbauer Hanns Juergen wrote:                   (Mon, 14 Jul 2003 10:31:54)
> I don't understand your second point. There is an MTP L3 between the TDM and
> the IP side, so both sides are decoupled. Thus I can't agree with this
> point.
> 
> greetings
> 
> HannsJuergen
> 

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

---

From: Tom George <[email-masked]>
Date: Thu, 17 Jul 2003 17:16:54 -0500

Brian,

In the non-IP realm, is it possible for a Q.703 to talk to a Q.2140? 
What would be done in the scenario you described?

tomG.

> other side follows Q.2140 and foregoes proving.  The following will
   [...]

-- 
* Tom George       PB7-24001 (near B-21)      [email-masked]  *
* 972-519-3168   Intranet:  http://www.ssd.usa.alcatel.com/~tgeorge/  *
* Alcatel;  3400 West Plano Pkwy,  MS PB7-SWPRO;  Plano, Texas 75075  *
*   I actively disclaim speaking for Alcatel.  I do not purport to    *
*   advertise or represent its position, operations, or activities.   *

---

From: "Brian F. G. Bidulock" <[email-masked]>
Date: Thu, 17 Jul 2003 17:54:56 -0600

Tom,

Q.703 does not give the option to talk to a Q.2140 link.  But it
appears that M2PA allows a Q.703-state-machine-based M2PA link to
talk to a Q.2140-state-machine-based M2PA link.  That is were the
problem ensues.

--brian

Tom George wrote:                                                                      (Thu, 17 Jul 2003 17:16:54)

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

---

From: Tom George <[email-masked]>
Date: Thu, 24 Jul 2003 15:28:29 -0500

That does not seem like a good situation. I see the point now. Instead 
of your suggested text:

would it be better to make a more general statement, in order to avoid 
this kind of problem that might exist in other procedures? Maybe I could 
  add to the 2nd paragraph in section 4:

=====
Except as modified in this document, M2PA SHOULD follow the
requirements of the applicable MTP2 specification. These may include
[Q.703] or [T1.111]. The same standard MUST be followed on both ends of 
the M2PA link.
=====

tomG.

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