[cisco-bba] ATM : VP & VCI

[raghuram chary]

 Bryan.,Thanks for explaining the  vpi/vci concept with a simple phone
number example.  :-)
Now I have got an idea of vp/vc.
Thanks a lot.

On Mon, Jan 5, 2009 at 9:58 PM, Bryan Campbell <bbc at misn.com> wrote:

> Let's make this a bit more simple.
>
> VPI/VCI is kinda like a phone number.
>
> Imagine the phone number 22-333-444-5555.
>
> A call to that number can be switched at country code (22), area code
> (333), exchange (444), or end customer digits (5555).  The only difference
> is that ATM is not native voice traffic.  It is ATM cell traffic.  And, the
> traffic can have switching treatment by VPI, VCI, or both, that is applied
> at layer 2 or layer 3 by the ATM network.
>
> The most comparable data technology is Q-in-Q vlan tagging.
>
> And, if you don't understand VPI-VCI now, you should read "Essentials of
> ATM Networks and Services" by Oliver C. Ibe.
>
> Enjoy!
>
>
>
>
>
> raghuram chary wrote:
>
>> Doug Thanks for the reply.But I couldnt understant what you are saying.
>>
>>
>> On Sat, Jan 3, 2009 at 1:23 AM, Doug McIntyre <merlyn at geeks.org <mailto:
>> merlyn at geeks.org>> wrote:
>>
>>    On Fri, Jan 02, 2009 at 08:05:35PM +0530, raghuram chary wrote:
>>     > Hi all,I'm unable to understand/imagine the VP and VC concept in ATM
>>     > technology.Can anyone explain the concept in detail?Any website
>>    pointers or
>>     > animated videos will also be appreciated.
>>
>>    Its much like a DLCI in frame relay or a VLAN tag in ethernet
>> networks..
>>
>>    An identifier to mark this cell/packet/frame/whatever is identified
>>    with this number and we differentiate that from other cells that could
>>    be for other things.
>>
>>    As to the reason for splitting the identifier into two seperate ones,
>>    ATM allows you to do path switching as well as VPI switching. You can
>>    take everything within the same VPI and push it out a different port
>>    than another.
>>
>>    You could have all of customers X traffic on VPI 10, and all of
>>    customer Y's traffic on VPI 11. Now, no matter how many VPI's customer
>>    X lights up, your switching setup continues to work without additional
>>    setup on your switching gear.
>>
>>    There's reserved VCI's so that also comes into play (ie. why the first
>>    PVC may be on 0/32 instead of 0/0 like you'd expect).
>>
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> cisco-bba mailing list
>> cisco-bba at puck.nether.net
>> https://puck.nether.net/mailman/listinfo/cisco-bba
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://puck.nether.net/pipermail/cisco-bba/attachments/20090108/dc537896/attachment-0001.html>