The 881 does not support T1. I do not believe that any router in the 800 series supports T1.
In terms of options you might consider obtaining a previously owned router that supports T1. Something like the 1841 comes to mind as a router that supported T1 and should be easy to find. There were routers like the older 1721 that might do. Bear in mind that with the older routers and the older code that they run there may be issues with security vulnerabilities present in that code.
In terms of current product line you probably want to look at one of the ISR routers like the 1921.
HTH
Rick
HTH
Rick
