Login | Register For Free | Help
Search for: (Advanced)

Mailing List Archive: Cisco: BBA

ATM : VP & VCI

 

 

Cisco bba RSS feed   Index | Next | Previous | View Threaded


raghujindia at gmail

Jan 2, 2009, 6:35 AM

Post #1 of 5 (2782 views)
Permalink
ATM : VP & VCI

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.

Thanks a lot.

Regards
Raghu


merlyn at geeks

Jan 2, 2009, 11:53 AM

Post #2 of 5 (2668 views)
Permalink
Re: ATM : VP & VCI [In reply to]

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
https://puck.nether.net/mailman/listinfo/cisco-bba


raghujindia at gmail

Jan 5, 2009, 6:41 AM

Post #3 of 5 (2644 views)
Permalink
Re: ATM : VP & VCI [In reply to]

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> 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).
>
>


bbc at misn

Jan 5, 2009, 8:28 AM

Post #4 of 5 (2644 views)
Permalink
Re: ATM : VP & VCI [In reply to]

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
> <mailto:merlyn [at] geeks>> 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
> https://puck.nether.net/mailman/listinfo/cisco-bba
_______________________________________________
cisco-bba mailing list
cisco-bba [at] puck
https://puck.nether.net/mailman/listinfo/cisco-bba


raghujindia at gmail

Jan 7, 2009, 9:44 PM

Post #5 of 5 (2635 views)
Permalink
Re: ATM : VP & VCI [In reply to]

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> 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 <mailto:
>> merlyn [at] geeks>> 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
>> https://puck.nether.net/mailman/listinfo/cisco-bba
>>
>

Cisco bba RSS feed   Index | Next | Previous | View Threaded
 
 


Interested in having your list archived? Contact Gossamer Threads
 
  Web Applications & Managed Hosting Powered by Gossamer Threads Inc.