Cell Relay Archive

[Thomas Frieling <thomas.frieling@arcormail.de>]

Scott Ferguson schrieb:
> 
> Thomas Frieling <thomas.frieling@arcormail.de> wrote:
> 
> > Usually not. Every time when a new connection is established, a
> > VPI/VCI-couple may be choosen from the pool regardless of the AAL
> > or other connection parameters. I can't imagine a situation where
> > the decribed suggestion with ranges would be helpful.
> > And: for incoming calls the network decides which VPI/VCI is to
> > be used, only for outgoing calls the endsystem may submit a
> > preferred value.
> 
> So I should be looking at the signalling protocols for establishing new
> connections.
> (...)

You asked: "...how do people typically determine which cells are
carrying which AAL?"
The answer is: not at all! Why should they? The endsystem knows
it, because it is configured manually or by signalling.

If you establish new connections manually in your own private
network there is no signalling, you make your own choice. If you
use SVCs instead you need not care about the actual
VPI/VCI-values. The signalling protocol doesn't look at the AAL
when it decides to allocate channel numbers.
If you want to know the terminating VPI/VCI of an SVC anyway and
there is no way to get the info from the endsystem (via SNMP)
then you can trace the signalling process and look for the
Information Element CONNECTION IDENTIFIER in the SETUP message
(called endpoint) or in the CALL PROCEEDING message (calling
endpoint).

Is that what you needed or have I missed the point?

Thomas