Subject: [HOKEY] Hokey minutes

From: Tom Taylor <[email-masked]>
Date: Thu, 12 Nov 2009 13:57:15 +0900

I wonder if I could offer an alternative to the meeting notes for my portion of 
the meeting. I am talking about the presentation:

"5.Second presentation – Tom Taylor: Can a Local ERP Server be separated from a 
Diameter Proxy?"

As a preliminary: the first entry under that heading belongs to the previous 
presentation. That is, move the following bullet up:

"- open Questions: additional architecture goals, local Domain Name Discovery, 
ERP capability discovery."

Following is my alternative text for this part of the session, based on 
Dorothy's notes and my own memory.

"5.Second presentation – Tom Taylor: Can a Local ERP Server be separated from a 
Diameter Proxy?

See slides for this presentation at 
http://www.ietf.org/proceedings/09nov/slides/hokey-4.pdf. In summary, these 
slides begin with one showing functional components and potential interfaces to 
the local ERP server. The remaining slides show
  - information flow requirements during the initial authentication phase
  - possible solutions (three alternatives) to achieve this flow
  - information flow requirements during the re-authentication phase
  - possible solutions for this phase.

Qin Wu sought clarification of the point about need for a "correlator", 
mentioned on the first information flow slide. Tom Taylor described this as some 
piece of information that is generated or provided during initial authentication 
and has to appear in re-authentication signalling sent to the local ERP server, 
to allow it to retrieve the DSRK instance applicable to this particular peer.

(Can't remember who) said this was an interesting analysis. It raises the 
thought that it might also be possible to decorrelate the home EAP server from 
Hokey functions.

At the end of the presentation, Qin referred to the various alternatives offered 
for the initial authentication flow and expressed his feeling that an on-path 
solution is to be preferred. Glen Zorn warned that we should not assume that the 
ERP server and Diameter servers or proxies are collocated. Such an assumption 
causes problems with Diameter and routing. With RADIUS the ERP server has to be 
on path. With Diameter, we don’t have to assume this. Gain flexibility in 
deployment and implementations, including fault tolerance. Do need to 
distinguish between ER-Diameter Agent and NAS-ER Server.