Digital Hierarchy

Committee T1 :

- Sponsored by the Alliance for Telecommunications Industry Solutions and accredited by ANSI for interoperability standards.
DCB's T1 Info :

- All you wanted to know about T1's but were afraid to ask.
EverythingT1.com :

- Offering T-1/T-3 information, glossary, FAQs, reference, Technical reports, news, messageboard, ISP lists and links.
SONET/SDH Technical Summary :

- Defines SONET and SDH, and provides references to appropriate standards organizations.
T-1 Carrier :

- Webopedia definition and links about T1.
T1 T-extender :

- DCB's T1 repeater for customer-owned cable.