Subject: [Megaco] MG's redundant configuration?

From: [email-masked]
Date: Thu, 23 May 2002 14:58:27 +0900

Hi, list.

In Section 11.3, Megaco 1.0 with correction,

"Allowing the MGC to send duplicate messages to both MGs accommodates pairs
of MGs that are
capable of redundant failover of one of the MGs. Only the Working MG shall
accept or reject transactions.
Upon failover, the Primary MG sends a ServiceChange command with a
"Failover" method and
 a "MG Impending Failure" reason. The MGC then uses the secondary MG as the
active MG. 
When the error condition is repaired, the Working MG can send a
"ServiceChange" with a "Restart" method."

I can't understand very well above paragraphs.
Let me draw some pictures.

                 Primary MG          Secondary MG               MGC
                     
                   active                       standby
                 fail detected
                        ----------------------------------------------------
------->
                                  servicechange(failover)

                        <---------------------------------------------------
-------
                                  servicechange reply

                    stanby                      active
 
At this point, if error condition is repaired. then which MG can send
ServiceChange with a "Restart" method?
And what is the effect of doing that? I mean "Restart"

And another question. 
1) In case of Failover because of MG failure. If failed MG have no chance
to Send ServiceChange with "failover".
   what is  the Standby MG supposed to do?
          - Should it issue ServiceChange with "failover"?
          - Should it issue ServiceChange with "disconnected" as described
in draft-hss-megaco-control-association-
            state-machine-00.txt"?

 - In draft-hss-megaco-control-association-state-machine-00.txt.
   Under Configuration of redundant MGs, MGs should have same mId.
   Everyone agreed to that? that's gonna be explicitly specifyed in megaco
specification?

  Thanks in advance.