DS3 migration Strategy

[uchaudhry]

Head end router(3845) is connected to five remote sites via individual T1s. Customer wants to move all the T1 connections from the remote sites to a DS3 cloud and move the head end router to a DS3 so that the Head end router would have a single DS3 connection out the cloud.The head end router is connected to different internet ISP as well. Remote sites will be partially meshed togther via T1s as well during the migration.

I am wondering what are the key parameters that I would have to worry about for this migration interms of routing. Would there be a one major interface and all the connections out to remote sites would be via subinterfaces with T1 bandwith statements on them.

[spilkinton]

I am assuming your DS3 connection will be Frame Relay?

At any rate, if you are using sub interfaces in a hub and spoke configuration (with connections between some sites), you still have the same number of IP addressed interfaces as you did with individual physical T1 connections. Thus, your routing design won't change.

In a migration scenario: you would bring up your sub interface on your ds3 at the Head End and also bring up the new circuit at the remote site. When the connection establishes and your verify everything is good; Switching connections would just mean adding the new sub-interface into your routing protocol. Assuming the router sees the new connection as a smaller distance/metric traffic should switch over to the new connection - which would allow you to then shut down the old T1 connection.

Scott

[jbrunner007]

what I dont understand, is why the dont just go with DMVPN? You can do a lot more for scalability and flexibility with connections into the headend, without the headend being tied to a private network...

You could conver the sites T-1s to internet T-1's and the DS-3 to an internet DS-3. Now you can add sites, and have the headend DS-3 for internet traffic... qos will govern the network...

[uchaudhry]

Client is has some heavy voice traffic going across the WAN. if qos marking for voice could be guranteed over the internet then it might be worth a shot.

[uchaudhry]

client cann not seem to provide me with much detail - i think it is going to be a clear channel - that is going to be channlized to the remote sites.

how would that work