Well, I can through some light on these. Basically IPLC is a pipe. We push in data at one end and get the same thing at the other end.
Say, We’ve a T1 line at US and connected to a TollFree. The telco forwards all the calls coming to the tollfree to our T1 and we’ll have a MUX at that end. The Mux in tun will have two interfaces, one for T1 (input)and an IPLC termination coneected thru a modem can be V.35 interface. The Mux compresses the T1 line for about 1:8 ratio (usind CELP or AD-CELP techniqies). The it goes to the IPLC provider AT&T, MCI or whatever it is.
On the other end, say India we’ll get the same v.35 interface with modem. we’ll terminate that at the MUX and we’ll take decompressed T1, as out put.
We use telnet to configure the MUX, on both the sides. The IPLC line problem is taken care by the Telcos, we’ll have to bug the guys at the both end VSNL and ATT or MCT. And telneting mux, requires the ip and login, these details will usually be with MUX guys.