Re: [Dime] Call for WG adoption: draft-jones-diameter-group-signaling-01

Hi Jouni, Tina and Mark,

I share the Jouni's point of view. If stateful proxies are required in the path, all messages related to the same sessions have to go through the same proxy.

If an implementation allows relying on multiple stateful proxies to manage the same sessions, this implementation needs also to support a mechanism ensuring a consistent management of the session data contexts between proxies. But IMHO, this kind of implementation is and should remain out of scope of any Diameter protocol spec.

Regards,

Lionel

-----Message d'origine-----
De : jouni korhonen [mailto:jouni.nospam@gmail.com] 
Envoyé : jeudi 12 avril 2012 11:03
À : Tina TSOU
Cc : dime@ietf.org; dime-chairs@tools.ietf.org; mark@azu.ca
Objet : Re: [Dime] Call for WG adoption: draft-jones-diameter-group-signaling-01

Tina,

On Apr 5, 2012, at 2:41 AM, Tina TSOU wrote:

> Hi Jouni and Mark,
> The problem statement is valid and the solution can work in basic scenarios. 
> 
> However the solution may have some limit in roaming scenario.
> 
> Consider a network having a WLAN AN (hosting a Diameter Client) requesting some 3G internet resources, visited network proxies and home network server as below:
> 
> Client -------------- <Visited n/w proxy 1> ---------- {Home network server}
>         -------------- <Visited n/w proxy 2> ----------{Home network server}
> 
> The session path can be established through either of the visited n/w proxies. For all the messages of same session, client can ensure that the session path through stateful nodes is maintained. The visited n/w proxies would require that the session path be maintained for offline charging etc.
> In this scenario, if client uses group signalling method to terminate all sessions in a group using GSTR, only the proxy in the GSTR-GSTA path will be aware of session termination. Since there are no follow-up messages, there is no mechanism to let the other proxy know that the sessions are terminated.

How this differentiates from a generic issue where someone
puts a proxy on path that is supposed to stay on path and
at the same time allows by deployment options an alternative
path to take place? Like asking for trouble..

> This problem can be avoided in Server initiated group signalling cases (GRAR & GASR) as the PER_SESSION mode can be used for follow up exchanges.
> Thus the current solution has a limit if client uses group signalling method for session termination in roaming cases.

The problem could also be avoided by not doing such deployment
where this can happen.

- Jouni

> 
> I volunteer to work together with Mark to find a solution for this case.
> 
> I'm NOT aware of any IPR in this area.
> 
> 
> Tina
> 
> 
>> -----Original Message-----
>> From: dime-bounces@ietf.org [mailto:dime-bounces@ietf.org] On Behalf Of
>> jouni korhonen
>> Sent: Sunday, April 01, 2012 12:20 PM
>> To: dime@ietf.org
>> Cc: dime-chairs@tools.ietf.org
>> Subject: [Dime] Call for WG adoption: draft-jones-diameter-group-
>> signaling-01
>> 
>> 
>> Folks,
>> 
>> During the Dime WG meeting in Paris we decided to adopt draft-jones-
>> diameter-group-signaling-01
>> "Diameter Group Signaling" as a working group I-D. The I-D is an input for
>> the charter mile stone 'Protocol extension for bulk and group signaling'.
>> 
>> This mail starts a one week verification for the adoption. If you have
>> strong concerns that the
>> draft-jones-diameter-group-signaling-01 is not appropriate as a _basis_
>> for the solution, then express your concerns on the mailing list by 8th
>> April.
>> 
>> - Jouni & Lionel
>> 
>> 
>> _______________________________________________
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