Subject: Uni-directional PVC connections in ATM-MIB

From: "Marek Malowidzki" <[email-masked]>
Date: Wed, 10 Sep 2003 11:46:13 +0200

Dear list members,

we have a quite basic question about appropriate (standard-compliant)
handling of uni-directional ATM PVC connections in ATM-MIB. RFC-2515 states
that:

"VCCs are bi-directional by definition.  However, the traffic parameters in
the two directions of a connection can be symmetric or asymmetric,
i.e., the two directions can have the same or different traffic
flows.  A uni-directional traffic flow across a VCC is achieved by
assigning a zero bandwidth in one direction."

The question is: how exactly one-way VCCs should be handled? Does it mean
that, for such connections, appropriate traffic descriptor index (e.g.,
atmVclReceiveTrafficDescrIndex) should be set to 0? (Another possibility
would be, theoretically, setting PCR in a traffic descriptor to 0, and
supplying such a TD as atmVclReceiveTrafficDescrIndex). I believe that the
first possibility applies (and this is why the AtmTrafficDescrParamIndex
TEXTUAL-CONVENTION allows the value of 0 while atmTrafficDescrParamTable
does not).

Thus, we guess that enabling traffic flow for such a direction should be
done through setting these TD indexes to non-zero values. Is this correct?

[if this issue has been discussed already, than excuse me for asking - there
is no search engine for the list archives; and it is hard to find anything.
The only thread I found was "Support for "split" unidirectional flows in
ATM-MIBs" from January 1999 with no reponse. Besides, the archive is
terribly spammed]

Regards,

Marek Malowidzki