PCC

PCC may refer to:

Science and technology

Organizations

3pcc

In the traditional telephony context, third party call control allows one entity (which we call the controller) to set up and manage a communications relationship or telephone call between two or more other parties. Third party call control (referred to as 3pcc) is often used for operator services (where an operator creates a call that connects two participants together) and conferencing.

Similarly, many SIP services are possible through third party call control. These include the traditional ones on the PSTN, but also new ones such as click-to-dial. Click-to-dial allows a user to click on a web page to speak to a customer service representative. The web server then creates a call between the user and a customer service representative. The call can be between two phones, a phone and an IP host, or two IP hosts.

Third party call control is possible using only the mechanisms specified within RFC 3725[1]. Indeed, many different call flows are possible, each of which will work with SIP compliant user agents. However, there are benefits and drawbacks to each of these flows. The usage of third party call control also becomes more complex when aspects of the call utilize SIP extensions or optional features of SIP. In particular, the usage of RFC 3312 [2] (used for coupling of signaling to resource reservation) with third party call control is non-trivial, and is discussed in Section 9 of RFC 3725 [3]. Similarly, the usage of early media (where session data is exchanged before the call is accepted) with third party call control is not trivial; both of them specify the way in which user agents generate and respond to SDP, and it is not clear how to do both at the same time. This is discussed further in Section 8.

Presidents' Conference Committee (Toronto streetcar)

The Presidents' Conference Committee Car was a streetcar used by the Toronto Transportation Commission and the Toronto Transit Commission. The PCC streetcar was designed by the Presidents' Conference Committee, a group of transit operators in the United States and Canada. The TTC version was built in Montreal, Quebec by Canadian Car & Foundry under license from the St. Louis Car Company of St. Louis, Missouri.

Of the 745 PCC streetcars the TTC owned—the largest fleet in North America—only two remain in operation. Cars 4500 and 4549 display their original 1951 fleet numbers, although renumbered 4604 and 4605 for record-keeping purposes after rebuilding in 1989. Classified A-15H (for Historic), the two cars are retained for charter service, although they often operate on summer Sundays on the 509 Harbourfront route.

Most of the PCC streetcars owned by the TTC were purchased new, although 225 were purchased secondhand from other transit companies as their PCC fleets were withdrawn from service. Many of the TTC's retired PCC cars were purchased by other organizations.