Subject: Question on MEGACO parsing

From: Steven Weisz <[email-masked]>
Date: Mon, 23 Apr 2001 11:01:50 -0400

Hi List,

From my analysis of the MEGACO protocol I am under the impression that when
parsing transactions an attempt is made to process as many commands as
possible. In other words, if we were only unable to determine the end of a
transaction (i.e. the closing "}" is missing) we still process all the
action.

Section 8.2.2 TransactionReply, paragraph 8 protocol states:

  "If the end of a transaction can not be reliably determined and one or
   more Actions can be parsed, it will process them and then return 403
   Syntax Error in Transaction as the last action reply for the
   transaction.  If no Actions can be parsed, it will return 403 Syntax
   Error in Transaction as the only reply."

However, what is not clear to me is what is the course of action when we
have many valid (error free)
commands when the end of an Action cannot be reliably determined.

In paragraph 7 the it states:

  "If the receiver encounters an error such that it cannot determine a
   legal Action, it will return a TransactionReply consisting of the
   TransactionID and a single error descriptor, 422 Syntax Error in
   Action. If the end of an action cannot be reliably determined but one
   or more Actions can be parsed, it will process them and then send 422
   Syntax Error in Action as the last action for the transaction."

My question is, when the end of an Action cannot be reliably determined but
the commands within the action can be, do we process said commands and place
the error descriptor, 422 Syntax Error in Action, at the end? Or is the
entire Action rejected?
 
Steven Weisz

---

From: "Madhu Babu Brahmanapally" <[email-masked]>
Date: Mon, 23 Apr 2001 11:38:35 -0400

Hi Steve,
This is a good input. Maybe in the next version we can discuss and introduce
a new error code "Syntax Error in Command", thus allowing processing of
commands that are correctly decoded. Thus providing more granularity in
identifying the error, and allow MG process what ever has been received
correctly.

In the "Syntax Error in Action" error code, IMO the MG shouldn't attempt to
process the commands in that Action. This way the MGC is completely aware of
what commands/actions were processed at MG and what are not processed.

Regards
Madhubabu

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Steven Weisz
Sent: Monday, April 23, 2001 11:02 AM
To: Megaco Mailing List (E-mail)
Subject: Question on MEGACO parsing

Hi List,

Steven Weisz