How many ways can you get multiple T-1s?

Nutter helps a reader negotiate T-1 options

My company is in the process of renegotiating our Internet service contract. We currently have two T-1s, and it looks like we can get three for the price of two. We’re being offered a DS-3 for transport, individual T-1s like we have now and a N+T-1 offering. What’s the best way to have the connection installed?

– Via the Internet

For the carrier to mention a DS-3, this tells me it’s looking to run a fiber connection to you. This means you might have to pay for some or all of the costs of a fiber installation. Just as important, you will have to have some type of fiber interface card for your router (one of Cisco’s offerings in this area is a T-3 card that you should be able to use – I checked with Cisco on this). There are two flavors of the card you can go with, a T-3 and a T-3+. The T-3 is cheaper but can only be used to connect to another Cisco router. The T-3+ can be a little expensive as it provides more flexibility on what it can connect to at the other end. See if the carrier pitching this option can put you on a SONET ring or some type of redundant connection to help prevent a fiber break from taking you down.

A N+T1 offering will involve running separate T-1s to your location and in most cases using Cisco’s CEF (Cisco Express Forwarding) protocol to handle load balancing between the T-1s. While this is doable, be advised that all of your T-1s will need to run to the same POP, which means if the POP goes down, you’ll be dependent on the carrier restoring service quickly to get you back up and running. If you want redundancy, see about having at least one of the T-1s homed to a different POP, but this will probably mean you will need to look at implementing Border Gateway Protocol and adding memory to the router to handle the routing tables that can be downloaded. This is a thumbnail sketch of what you’re looking at based on the information you gave me. I would strongly suggest a call to Cisco and see if one of its field engineers can stop by and give you an independent view of your connectivity options. If you’re not using Cisco routers, check with your vendor’s tech support group to see what it can help you with.