Cell Relay Archive

[Afroz Lateef <afroz.lateef@fnc.fujitsu.com>]

An SVC has signalling from the source CPE to the destination CPE (a la
telephones, where you pick the phone and dial the number, then the call gets
routed and connected to the other phone).
An SPVC has a permanent connection between the CPEs and the ATM switches.
Between these ATM switches is SVC (signalling) => SPVC = PVC + SVC.
So in case of trunk failures, since PVC between the CPE and the switch is not
affected, the SVC part of the call gets re-routed and re-established. Whereas
for SVC, the call simply gets dropped and has to re-initiated via setup
messages.

Afroz Lateef


hal@blackfoot.net wrote:

> By SPVC, do you actually mean SVC (switched virtual circuit)?  I am
> not familiar with SPVC.  An SVC is simply a dynamic circuit which is
> built and torn down by ATM switches using an NNI interface.  This
> functionality exists so that you don't have to manually build VC's
> through multiple switches in a large ATM network.
>
> For more info on this and the rest, the best book I have seen on an
> ATM backgrounder is ATM Networks by Handel, Huber, and Schroder.
> Addison-Wesley pub., ISBN 0-201-17817-6.
>
> On Thu, 3 Aug 2000 22:57:17 -0400, "Shahin M. Ansari" <sansari@uu.net>
> wrote:
>
> >Geetings-
> >   Please make sure you reply to my email as well.  I know ATM is related
> >to ISDN, and its precursors are from the LAN environment.  I am trying to
> >understand the difference between SPVC and PVC if you will.  Can anyone
> >explain the differences and similirities between a digital circuit, T1
> >technology, ISDN, atm, Frame Relay.. and any other ones you think might
> >help me understand differene between a PVC and SPVC?
> >
> >Sincerely,
> >  Sean
> >
>
> Hal Dorsman
> Data Network Engineer
> Blackfoot Telephone Cooperative
> Missoula, Montana, USA
> hal@blackfoot.net
> (406) 541-5106