service-module versus controller commands

[donlon]

I'm unclear why two commands exist that apparently handle setting framing & linecode types for T1 lines.
On 2600's I've seen the "service-module" command for WICs with an integrated CSU/DSU, yet on larger routers the "controller" command seems to be used.

Can anyone enlighten me why there's two commands and when to use one versus the other?

donlon