[c-nsp] High Density T1 aggregation device - migrating to MPLS

[Jeremy Bresley]

On 12/3/2010 12:16 PM, Rick Martin wrote:
>
>   We are in the planning stages for a conversion to an MPLS infrastructure, we have about 3,000 connections on this statewide network which spans 3 major carriers territory. We expect we will wind up with one vendor at the core. Assuming vendor A wins the core we expect we will have to provide hardware to aggregate connections from vendor B and C's territory and pass those connections on to the core via Ethernet.
>
>   Our expectation is that we will have 2 types of last mile connections to our customers - Ethernet and MPPP via T1's. Of course our preference would be Ethernet for all of the WAN links but at this time that is not possible due to the rural nature of portions of our state. We expect perhaps 50 - 100 T1's at a given aggregation point.
>
>   I am in need of advice on what products are available for high density aggregation of the T1's. I am currently researching Cisco products but do not want to limit my scope to Cisco only. I would welcome any suggestions or advice on this.
>
> Thanks in advance for your suggestions
> rick
>
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Biggest question with aggregating T1s would be whether to get an 
external MUX to aggregate T1s into DS3/OC3s, or whether your carrier(s) 
can do this and hand off DS3/OC3s to you.

If you can get DS3s or OC3s handed to you, a channelized DS3 or 
channelized OC3 card in a 7200 or ASR should be able to handle this 
easily.  If you have discrete T1s coming in, you're probably looking at 
several routers to handle 100 T1s.  Most of the T1 cards only scale to 8 
ports.  100 T1s would be able to be handled by 4 channelized DS3 cards.

If your carriers can't hand you off DS3/OC3, one option would be to feed 
the T1s into one or more M13 MUXes (Adtran MX2800 series is one example 
of these.)

One thing to double check on the channelized cards is that there are no 
known issues with running MLPPP across them, and verify if all the T1s 
would be on the same DS3, and running MLPPP across multiple cards was 
problematic with the 7200 cards.

Jeremy