Re: [Agentx] Benefit of multiple sessions per sub-agent connection

"Randy Presuhn" <randy_presuhn@mindspring.com> Thu, 01 July 2010 21:40 UTC

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From: "Randy Presuhn" <randy_presuhn@mindspring.com>
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Subject: Re: [Agentx] Benefit of multiple sessions per sub-agent connection
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Hi -

> From: "Julian Scheid" <julians37@googlemail.com>
> To: <agentx@ietf.org>
> Sent: Thursday, July 01, 2010 6:07 AM
> Subject: [Agentx] Benefit of multiple sessions per sub-agent connection
>
> Could someone give a practical example of when a sub-agent would want
> to open more than one session per connection?

Examples that come to mind are when the subagent is functioning as a
gateway to some other subagent protocol, bridging to a transport
protocol not supported by the master agent implementation, or both.
I suppose it could come in handy with a connectionless subagent transport,
but that seems to me to be a bit of a stretch.  There might be other uses,
but I've been away from this stuff for a long time.
 
> I've written a sub-agent implementation whose code and API would be
> simpler if it would limit users to a single session per connection,

There really isn't much reason to expose session ID in a subagent API.
Assuming you have some kind of constructor that returns a session object,
the session ID would be private data that only the library, and not the
user code, would ever have to llok at.

> and I am wondering what benefits it would deprive them of by doing so.
> As you might guess, I'm hard pressed to come up with use cases myself
> -- I must be missing something.
> I'm not exactly an SNMP expert, my apologies if this is a silly question.
> 
> Thanks in advance.

Not silly at all.  As I recall, this was a "borderline" feature of the protocol,
dating from a time when lots of things other than AgentX were in use,
and the need to be able to build ways to support legacy subagents was
a real concern.

Randy