T1: A Survival Guide

Assumptions This Book Makes

When writing about telephony, a recurring challenge for authors is deciding what to leave out. No matter how detailed the text, some low-level details must be omitted to keep from inundating the reader with potentially interesting, but pointless, detail. I have left out a great deal of detail from the formal standards, published by ANSI. Appendix F lists a wide variety of relevant documents for interested readers.

This book is about using T1 to transmit data from one point to another. It does not address using T1 as a voice transport, except insofar as to explain why some parts of the T-carrier system evolved the way they did. No material on channel banks is in this book, except in some places to add a historical perspective. Finally, this book steers completely clear of pricing—it is about deploying and technically managing T1 services, not about using T1 for any particular economic reason.

Familiarity with the seven-layer OSI model is assumed. With rare exceptions, this book stays at the first layer (physical) and the second layer (data link). Basic understanding of electronics and the physics of wave propagation is helpful, but not required. Complete descriptions for several of the protocols would take up entire books. SNMP, HDLC, PPP, and frame relay are all discussed as they relate to T1; a relatively solid background is assumed.