Cell Relay Archive

[Syam Madanapalli <syam.Madanapalli@axa100.am.ericsson.se>]

Title: Re: I have a question of the VPI/VCI assignment scheme of ATM switch

Hi,
     I think it is better not to use the recently used VCI/VPI values, because
the other end might not have released the same immediately.

Regards
Syam

> Some devices only go up to a certain VCI/VPI range and then loop and start
> incrementing again. One vendor out there only goes up to 500 then loops. You
> may want to check these limits if using different devices / vendors.
>
> Paul Koning <pkoning@xedia.com> wrote in message
> 376E7D7C.E8BFD091@xedia.com" TARGET="_blank">news:376E7D7C.E8BFD091@xedia.com...
> Meng-Hsi Chiu wrote:
> >
> >     Becaue the ATM forum recommendations, VCI range from 0 to 31 must
> > reserve for
> >
> > special usage. So the user's VCI is ranging from 32 to 65535 in theory.
> > My question
> >
> > is:
> >
> >     How the ATM switch will assign the VCI range? Is it assigned from
> > VCI=32, then
> >
> > VCI=33, then VCI=34, then VCI=35? If the first connection(its VCI=32)
> > release
> >
> > connection now, what VCI number will be assigned for next call setup,
> > whether it is
> >
> > 32 or 36?  It is important to us, please answer me.
>
> It depends on the switch.  I don't know any specific rules used;
> certainly the standards have nothing to say about it.
>
> Why is it important?  Or rather, if it's important in your system
> you probably have a bad design decision somewhere, because nothing
> in your design should depend on a particular assignment rule.
>
> paul

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