Subject: FW: [midcom] Out-of-path agents

From: "Cedric Aoun" <[email-masked]>
Date: Thu, 28 Jun 2001 23:50:33 +0100

Melinda, 

I prefer that we don't close the door to any deployment scenarios.

How about putting a small paragraph on :

Location of the MIDCOM Agent:
The MIDCOM agent could be co-hosted with an application client or server
already part of the application, or could be co-hosted with several
client/server applications that are completely invisible to the application
end parties.

-The first MIDCOM Agent type, the In Path Agent, requires to add the MIDCOM
agent on to existing hosts thus requiring upgrade of the host (neither S/W
or H/W), additional processing power (that might require the processor
upgrade) and implicitly an additional cost required per application.

-The second case, describing the Out Of Path agent, leaves the end parties
completely unaware of any MIDCOM interaction, there is no upgrade
requirements (software or H/W) in some cases this solution could be applied.
However there are some drawbacks to the invisibility of the MIDCOM Agent,
when encrypted application signaling is sent the agent can not determine the
used encryption key since it did not participate to any key exchange.

In addition the OOP agent requires packet diversion capabilities on the
Middle Box, these might be achieved by the following procedure:
-Create a relation between an application (identified by a source or
destination IANA assigned port) and a MIDCOM agent
-Establish a tunnel between the Middle Box and the required MIDCOM agent
-Hijack the application traffic type (identified by IANA port numbers or
protocol port depending on application type) and route it to the tunnel
interface
-Load Sharing policies between MIDCOM agent are required (for obvious
scalability reasons several MIDCOM Agents might be required)

The OOP MIDCOM agent will require to have load monitoring notification
messages (which is optional) Middle Box to choose between the MIDCOM agents.
--------------
We all agreed that the framework is around providing a mean for application
aware entities to request from intermediate network elements certain
parameters to allow the application traversal.
Within the framework we should cover the different types of MIDCOM agents,
even if they do not require any additional requirements within the MIDCOM
protocol it is still necessary to high-light the 2 different types.

Thanks
Cedric

-----Original Message-----
From: Melinda Shore [mailto:[email-masked]]
Sent: Wednesday, June 27, 2001 9:28 PM
To: midcom
Subject: [midcom] Out-of-path agents

Thumbs down - let's make text related to out-of-path agents and
packet diversion disappear from the deliverables.

Thanks,

Melinda

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---

From: "Melinda Shore" <[email-masked]>
Date: Fri, 29 Jun 2001 08:33:58 -0400

> Middle Box, these might be achieved by the following procedure:

Really, we can't do this.  It's being regarded as an expansion of
scope, and we don't have the work that's in scope completed yet.

Melinda