Subject: RE: [Megaco] Questions about auditing terminations

From: John Stock <[email-masked]>
Date: Fri, 11 Apr 2003 16:49:58 -0700

Anyone?

Thanks.

-----Original Message-----
From: John Stock [mailto:[email-masked]]
Sent: Monday, March 17, 2003 10:00 AM
To: [email-masked]'
Subject: [Megaco] Questions about auditing terminations

Hi,

I have a few questions about auditing terminations.  The case I'm concerned
about is where an MGC wishes to audit individual terminations in the MG.
The MGC may or may not know the state of the termination in a call, i.e.
whether or not it's involved in a context or not.  This may arise out of
these conditions I can think of:

1.  The MGC resets and loses its connection database, and wants to query the
MG to rebuild it.
2.  The MG performs a switchover and loses a connection which it has Replied
to the MGC.  The MGC now has the context/term relationship but the MG does
not.  The MGC may wish to audit the terminations which had recent activity,
based on receipt of ServiceChange with method Disconnected.
3.  Other bad stuff like message loss, software bug, etc.

My questions are:

- In version 2, there's a new mechanism to retrieve a ContextID for a
termination, using AuditValue with a specific TerminationId and a ContextId
of ALL.  However per the spec this applies only to non-NULL contexts.  Why?
The MGC may not know whether or not the termination is involved in a
context, thus it seems inappropriate for the MG to fail the command if the
termination is in the NULL context.  It seems like it would be appropriate
to just return a null ContextId if the termination is not in a call.

- Relating to the previous question, it seems like it would be appropriate
for the MGC to use a value of CHOOSE in this case instead of ALL.  ALL
implies that multiple values may be returned, however since a termination
can only be involved in one context at a time this isn't valid.  I know the
MG isn't creating a new Context here, but it seems like in the AuditValue
case the CHOOSE ContextId could be defined to query an existing ID instead
of creating a new one.

- The spec seems to be quite ambiguous regarding wildcard values, especially
for ContextID.  The text ABNF lists (UNIT32 / "*" / "-" / "$") as valid
values for ContextId, however nowhere in the ABNF, or even elsewhere in the
spec (that I can see - maybe I'm missing it), does it explicitly say what
each of these parameters means, nor does it state in the referenced RFC2234.
The only mention that "$" is used for CHOOSE is in the last sentence in B.1:
"The CHOOSE TerminationID '$' may be used to signal to the MG that it has to
create an ephemeral Termination...", however this seems to be merely a
descriptive paragraph and not a specification, and doesn't even reference
ContextID; it's discussing TerminationID.  I'm actually more concerned about
"*" vs. "-"  -- which one of these is ALL?  I'm sure it's the former, but it
doesn't seem to be specified anywhere.

Thanks.

John Stock
Systems Engineering
Advanced Fibre Communications
[email-masked]
707-792-6249

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---

From: John Stock <[email-masked]>
Date: Fri, 11 Apr 2003 16:49:58 -0700

Anyone?

Thanks.

-----Original Message-----
From: John Stock [mailto:[email-masked]]
Sent: Monday, March 17, 2003 10:00 AM
To: [email-masked]'
Subject: [Megaco] Questions about auditing terminations

Hi,

My questions are:

Thanks.

John Stock
Systems Engineering

---

From: Arnab Sengupta <[email-masked]>
Date: Sat, 12 Apr 2003 11:17:10 -0400

John,

A quick solution to your problem could be to send two Optional AuditValue
commands for the same termination; one on ALL context and the other on NULL
context. That way, the MG would return a positive reply for one and an error
for the other, thereby returning the state information of the termination.
An example transaction could look something like this:

Transaction = 111 {
   Context = * {
                O-AuditValue = TermA {
                     Audit {Media}
                   }    
                  },
   Context = - {
                O-AuditValue = TermA {
                     Audit {Media}
                  }
                }
         }

Regards
Arnab

-----Original Message-----
From: John Stock [mailto:[email-masked]]
Sent: Friday, April 11, 2003 7:50 PM
To: John Stock; [email-masked]'
Subject: RE: [Megaco] Questions about auditing terminations

Anyone?

Thanks.

-----Original Message-----
From: John Stock [mailto:[email-masked]]
Sent: Monday, March 17, 2003 10:00 AM
To: [email-masked]'
Subject: [Megaco] Questions about auditing terminations

Hi,

My questions are:

Thanks.

John Stock
Systems Engineering

---

From: Arnab Sengupta <[email-masked]>
Date: Sat, 12 Apr 2003 11:17:10 -0400

John,

Transaction = 111 {
   Context = * {
                O-AuditValue = TermA {
                     Audit {Media}
                   }    
                  },
   Context = - {
                O-AuditValue = TermA {
                     Audit {Media}
                  }
                }
         }

Regards
Arnab

-----Original Message-----
From: John Stock [mailto:[email-masked]]
Sent: Friday, April 11, 2003 7:50 PM
To: John Stock; [email-masked]'
Subject: RE: [Megaco] Questions about auditing terminations

Anyone?

Thanks.

-----Original Message-----
From: John Stock [mailto:[email-masked]]
Sent: Monday, March 17, 2003 10:00 AM
To: [email-masked]'
Subject: [Megaco] Questions about auditing terminations

Hi,

My questions are:

Thanks.

John Stock
Systems Engineering