Please Help, Don’t know what to do with dual DSL.

Hello, i have a two DSL connection in the internet cafe and we have 50 units on it. The owner want to have a dual DSL connection, 25 units for DSL #1 and another 25 for DSL #2. Now the problem is we have different IP address in our router and he want that the two different router must see each other for our lan connection..

I don’t know what to do enable to achive a dual DSL connection with the same IP address.