Doug Thanks for the reply.But I couldnt understant what you are saying.<br><br><br><div class="gmail_quote">On Sat, Jan 3, 2009 at 1:23 AM, Doug McIntyre <span dir="ltr"><<a href="mailto:merlyn@geeks.org">merlyn@geeks.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div class="Ih2E3d">On Fri, Jan 02, 2009 at 08:05:35PM +0530, raghuram chary wrote:<br>
> Hi all,I'm unable to understand/imagine the VP and VC concept in ATM<br>
> technology.Can anyone explain the concept in detail?Any website pointers or<br>
> animated videos will also be appreciated.<br>
<br>
</div>Its much like a DLCI in frame relay or a VLAN tag in ethernet networks..<br>
<br>
An identifier to mark this cell/packet/frame/whatever is identified<br>
with this number and we differentiate that from other cells that could<br>
be for other things.<br>
<br>
As to the reason for splitting the identifier into two seperate ones,<br>
ATM allows you to do path switching as well as VPI switching. You can<br>
take everything within the same VPI and push it out a different port<br>
than another.<br>
<br>
You could have all of customers X traffic on VPI 10, and all of<br>
customer Y's traffic on VPI 11. Now, no matter how many VPI's customer<br>
X lights up, your switching setup continues to work without additional<br>
setup on your switching gear.<br>
<br>
There's reserved VCI's so that also comes into play (ie. why the first<br>
PVC may be on 0/32 instead of 0/0 like you'd expect).<br>
<br>
</blockquote></div><br>