Subject: [AAA-WG]: Msg Header Identifiers??

From: "Martin Julien (ECE)" <[email-masked]>
Date: Thu, 19 Apr 2001 16:43:10 +0200

Hi,

Should messages received with an un-expected Hop-by-Hop 
or End-to-End Identifier in the header be discarded?, 
or should a DSI or MRI be sent? I think it SHOULD be locally
logged, and MUST be discarded. What do you think?

Should duplicates be also discarded? I would assume that
a duplicate message detected based on the Hop-By-Hop Identifier
should be discarded, while a duplicate message detected based
on the End-to-End Identifier is not so obvious to me.

The introduction of the End-to-End Identifier was to detect
when a Diameter client was re-sending a pending request, since
it was impatient. Now that we have the DSI-Event "STILL_WORKING",
and the Max-Wait-Time AVP, do we still need the End-to-End 
Identifier? 

Anyway, the thing is that if a duplicate detected based on the 
End-to-End Identifier is received in the Home server while it is still 
processing the previous request, should the Home server send an
MRI with a new Result-Code to "Duplicate Message-Still Working"?
That would make sure that the Diameter nodes on the way to the Home
server do not retry to re-send once more the duplicate message
as well. The "Duplicate Message-Still Working" would be an End-to-End
error of type Permanent.

/Martin

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From: Patrice Calhoun <[email-masked]>
Date: Thu, 26 Apr 2001 11:02:39 -0700 (PDT)

> logged, and MUST be discarded. What do you think?

I presume you mean messages of type Response or Answer, and I believe you are
correct. 

> on the End-to-End Identifier is not so obvious to me.

For Request, Query or Indication messages, I don't think so. Perhaps there is
a problem in the proxy chain that caused a message to take two paths. For
responses or answer, yes it can be discarded.

> and the Max-Wait-Time AVP, do we still need the End-to-End 

A home server may want to minimize processing unnecessary packets, and the E2E
ID would allow it to queue recently sent responses. Of course, the
Record-Route AVPs and Proxy-State (now Proxy-Info) should have to change.

> MRI with a new Result-Code to "Duplicate Message-Still Working"?
see above on home servers being able to queue recent responses.

> as well. The "Duplicate Message-Still Working" would be an End-to-End
I am not sure that we can guarantee that a dup message will never occur, and
we need to handle such cases when failures in the network occur.

PatC