adventures of a VoIP / SIP / IMS trainer & contractor|


Rotary phone – Kellogg K-500 decomposed

For the past few months, I’ve been regularly lecturing on the architecture of the IP Multimedia Subsystem, and VoLTE access. Therefore, I thought it fitting to take a step back and explore some classic telephony.

Western Electric produced the WE 500 in 1949, a design that was Bell’s standard issue deskphone from 1950 to 1984 (when the Bell divestiture into ‘Baby Bells took place’).

The following is a decomposed view of the a Kellogg 500 (K-500) from 1958, which was produced by Kellogg / International Telephone and Telegraph (ITT) under licensed permission from Western Electric. The K-500 is identical to the […]

Star Trek : The Star Codes Generation

CLASS codes, Vertical Service Codes (VSCs), or the ‘Star Codes’, were all names for a list of codes developed in the late 60’s and early 70’s by AT&T Bell Labs. These codes began with an ‘ * ‘, and allowed PSTN customers to mail their phone companies large amounts of money. In exchange, users were able to enable fancy PBX features on a per-call basis. All of these codes preempted the dialing process, and were usually 2 or 3 digits in length (although each telephone provider may have their ‘own’ unique list).

By the way, the name VSCs harkens back […]