Subject: Re: [Pana] PAA-2-EP protocol requirements

From: [email-masked]
Date: Mon, 1 Dec 2003 09:21:49 -0800

> below are some other PAA-2-EP functionnalities (open list). should we
   > consider them as also required ? not required at all ? supported
   > elsewhere ? any alternative ?
   >
   > a) Inactive peer detection:
   > The protocol used between PAA and EP should be able to detect inactive
   > peer within an appropriate time period. This can be achieved by having
   > both the EP and remote PAA constantly verify their connection to each
   > other via keep-alive messages: a heartbeat in fact.

   I'm not sure how much "explicit support" we need for this from the
   PAA2EP
   protocol. There can always be ad-hoc solutions to this. For example,
   running
   some request-reply messages between the PAA and EP can be used as a
   keep-alive. I can imagine an implementation resorting to such techniques
   when the protocol does not have a dedicated facility....

Yes, some SMNP implementation can support small value (order of seconds)
for
miminum polling inverval.  This would be sufficient for inactive peer
detection, but
not sufficient for detecting _rebooted_ peer when rebooting can complete
within
SNMP polling interval. Rebooting detection is needed when EP store
PaC information (including accounting information) in volatile memory.

So we might need to define some rebooting counters in SNMP MIB in order to
detect
rebooting peers, or if such a MIB already exists we might just specify the
use of
the MIB for both inactive/rebooted peer detection.

   >
   > b) Stateful approach:
   > The protocol must allow to maintain some states in the PAA in order
   for
   > an EP that went down and came back up, or an EP that is being
   introduced
   > in the network to (re-)synchronize with the PAA.

   We can assume PAA always has the associated state. It'd have a list of
   authorized PaCs and their attributes... I don't think this is something
   for
   PAA2EP protocol to worry about...

   > In general terms, the PAA-EP protocol needs to support the stateful
   > model between the PAA and the EP(s) and some other mechanism for the
   EP
   > to learn the policies currently in effect on that access network.
   >
   > c) Accounting/Feedback from the EPs:
   > The PAA must have an efficient way to to get the accounting
   information
   > of PaC from EP since the PAA may be a client of the AAA backend
   > infrastructure.

   Getting statistics from the EP makes sense. For example, in the case of
   SNMP, if we get the counters from the EP this is good enough. The AAA
   client
   sitting on the PAA can turn these into accoutning records.

I agree.  Should we eliminate the case where EP itself directly sends
accounting records
to the accounting server?  I am asking because AAA clients for
authentication sessions
and accounting sessions can be separated entities in Diameter, as long as
there is a way to
associate an accounting session with an authentication session.

Yoshihiro Ohba

   Alper

   > d) ????
   > thanks,
   > Yacine El Mghazli

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From: [email-masked]
Date: Tue, 02 Dec 2003 11:40:56 +0100

Hi Yoshi and al,

> accounting records to the accounting server?  I am asking because AAA clients for
> authentication sessions and accounting sessions can be separated entities in Diameter, as long as
> there is a way to

I agree. this is an important issue: is polling sufficient for the AA 
purposes ?

FYI, SNMP provides event-based notifications. I'm not sure if an SNMP 
agents (EPs) can send records periodically to the manager (PAA)...

Yacine

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From: [email-masked]
Date: Tue, 02 Dec 2003 11:40:56 +0100

Hi Yoshi and al,

Yacine

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From: [email-masked]
Date: Tue, 02 Dec 2003 11:49:06 +0100

hi Yoshi:

> the MIB for both inactive/rebooted peer detection.

I'm not sure to rightly understand what you mean here, please can you 
elaborate ?

thanks in advance,
Yacine

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From: [email-masked]
Date: Tue, 02 Dec 2003 11:49:06 +0100

hi Yoshi:

thanks in advance,
Yacine