In purchasing this router, I was told that since we had a “DSL modem” that the Cisco 867W Integrated Services Model was the correct one vs. the 861W model. My question is regarding just the basic setup of the new router to my CenturyTel/Embarq (local phone company’s) modem. The set up in our equipment room is the following: the DSL/telephone line (RJ-11) runs from the wall outlet into the input on the high speed modem; then the output from the modem is an RJ-45 port. (I used to connect the RJ45 over to the Linksys BESFX41 router). The new 867W came with a DSL cable ( I am assuming it to be a RJ12) and when I connect this from the ADSLoPOTS Port into the modem’s RJ45 it “clicks” into place; however I am not confident that this is the correct connection and if this could potentially cause harm to the modem or router? (there is no RJ45/or other WAN connection on this router only an Auxiliary/console RJ45 inlet)
If I cannot continue with using the RJ12 cabling thru to the modem, is there any other connection that I could do to make this router work without compromising connectivity or should I return this router and get a different one? If so, is the 861W which would be the broadband/cable model best choice?
Cisco 867W has an ADSL port so to use it you should connect the RJ-11 cable coming from the provider to it, you cannot connect it downstream to existing modem using the DSL WAN interface, because it is not an ethernet port but an ethernet port.
You may connect a LAN port to the RJ45 port of the modem you should configure it in a different Vlan in order to act as external interface.
However, as you have noted, If you want to keep using the existing modem, you should move to a different router model like C861.
see datasheet with 861 and 867 models
to be noted C867 DSL interface supports ADSL 2/2+ (Annex A) that may improve your DSL performance if your current modem supports only ADSL version 1. But troubles have been reported in UK with ADSL 2+ and some cisco devices (The issue should be UK specific)
Hope to help