usable T1 bandwidth

How much of the 1.544 Mbits/second of a T1 are available to IP? I know some bits are taken for framing and such. I think I remember it is around 1.3 something.

It's 1.536 Mbps. This is 64000 x 24. The other 8k goes to framing overhead. It's full-duplex. Can we stop the flames now? Daniel Minoli has put out some good books that cover the low-layer telecom transports, check with your local bookstore. -- Shields, CrossLink.