Is it possible to connect between two routers using their E%M interfaces and ping through the routers between two PCs (the ethernet interfaces do have ip addresses)?
E&M is a form of analog telephone circuit used for PBX trunks. Not suitable for packet-based data communication. With the proper wiring you could use two E&M circuits back-to-back as a voice link for telephony.
Not suitable for IP, however.
I overlooked PC to PC communications.
Not possible Danny.
In short, no.
The E&M interfaces allow for analog telephony connectivity and does not support digital layer 3, or layer 2 addressing so pushing digital packets through them can not work.
An E&M interface connects the cisco device to a telephony trunk with analog signaling for communication to a connected analog interface such as that in a PBX or telco.
The links mentioned in the above post will clearly explain what E&M can do and pushing packets is not possible.
Never tried this but looks like you can do this.
Here's what mentioned in one of the cisco document -
"The Cisco analog E&M interface functions as the signaling unit side and it expects the other side to be a trunk circuit. When you use E&M interface models Type II and Type V, two signaling unit sides can be connected back to back by the appropriate crossing of the signaling leads. When you use E&M Type I interfaces, two signaling unit sides cannot be connected back to back." -
This link talks about the wiring -
Goold luck mate.