I couldn't find whether this module can be used as a central site DSL device(the client function is sure). This is needed to directly connect to Cisco router equipped with HWIC-1ADSL modules. I was using by now two Zyxel modems, but there is a difference between the two models (one of them is especially specified as a cetral side modem).
I will appreciate any answer!
back to back connections are possible only with SDSL SHDSL modules.
All adsl modules are only capable to perform the client side role (ATU-R).
You need two network modules or VWICs for SDSL SHDSL
Hope to help