Hi
The term channel is used by Infineon in their datasheet. I agree that it can be missunderstood. For them, one channel = one block. One block is made of one line interface, one framer and one HDLC controler.
In the past, I used to use Infineon (Siemens) chips like PEB2235/2236, PEB 2035 and SAB82525. All of these references were grouped in one : the FALC.
At the moment, I use PMC SIERRA chips. I did this choice because of the high level of integration of their solution, up to eight channels (block) in one chip.
In a general maner, I think that the offer of the most popular providers is about the same in term of integration. Only the price per line and the support can be the main differences.
If the price and support are not the major aspects of your choice, start your development with the family (provider) you are familiar with. This will cost you less time in hardware and software (drivers) developement.
On another hand, the availability of line transformers can be a problem. The ones are prefer are PE (h**p://www.pulseeng.com/), MIDCOM (h**p://www.midcom-inc.com/) and VAC (h**p://www.vacuumschmelze.de)
Today, if I would have to start a E1/T1 design from zero, I would have a look at DALLAS/MAXIM, INFINEON, PMC SIERRA and ZARLINK solutions.
Sorry for xDSL, I dont have any reference on the subject.
Regards
Papyaki