two-factor authentication, via T1?

[dgonzalez () merituspayment com]

Hello list, 

Does anyone have or has had experience with two-factor authentication via a T1 link?

Here is the issue I have. 
I have a Co-Lo housing all server systems. The office I work from is connected to the Co-Lo via T1 link. We have 4 
network segments (for PCI purposes) and to access the server segment, I need to implement two-factor authentication. I 
use remote desktop to access servers, but this is not enough. I am having trouble since I am connected to the Co-Lo via 
T1 on how I could implement this two-factor authentication.

Thank you in advanced.

dgonzalez