Basics of Telephony

Inside the Telephone
Quick and simple document detailing how an analog telephone converts speech into electricity and back again.

Nortel's Telephony 101
An excellent primer on how traditional TDM telephony services are delivered in North America.

T1 Service Fundamentals
Thorough and useful document explaining how T1 (and, by extension, all other TDM transmission) works.

Fiber Capacities
Demystifies the difference between DS0, DS1, DS3, OC3, OC96, and so on.

SS7 Tutorial #1
A good overview of how Signaling System 7 works in North America.

SS7 Tutorial #2
Another excellent SS7 primer; this one doesn't go into as much detail as the first document, but it is definitely easier to understand (and also comes with an awesome quiz so you can test yourself).

United States area codes as of 1 October 2003

California Telephone Exchange Areas
This is a beautiful map detailing the various exchange areas of California, which telephone company serves those areas, LATA boundaries, area code boundaries, and associated goodness. Another fine document from the California Public Utilities Commission.

Verizon Wireline Footprint Map (2006)
Verizon Communications' wireline footprint in the continental United States as of January 2006.

Issue 1 - February 2005

Issue 2 - July 2005

Issue 3 - February 2006

Issue 4 - August 2006

How AT&T Wireless Got Disconnected
Analysis of network coverage and market share of Verizon Wireless, Cingular Wireless, and AT&T Wireless just before Cingular's acquisition of AT&T Wireless in 2004.

Verizon Headquarters - 140 West Street
Overview of 140 West Street, New York, New York. This building is legendary and is now the Verizon world headquarters.

DMS-10 500 Series Platform
Explains the new generation (as of 2000) of DMS-10 hardware available from Nortel.

DMS-10 504 Generic Release
Details features of the 504 release of the DMS-10 switch generic (operating system and application software).

DMS-10 505 Generic Release
Details features of the 504 release of the DMS-10 switch generic.

DMS-10 Evolution to VoIP
Basic description of the new 600 series generic for the DMS-10 and simple modifications which make the switch VoIP-capable.

DMS-10 Software Policy
Telephone switches go through constant software upgrade cycles; this document details Nortel's software life cycle policies.

603-050-010 Issue 1 - December 1965
Removing Manhole Covers