In video teleconferencing, pertaining to a family of CCITT (now, ITU-T) Recommendations, where p is a non-zero positive integer indicating the number of 64 kb/s channels. Note: The p × 64 family includes Recommendations H.261, H.221, H.242, H.230, and H.32
0. These Recommendations form the basis for video telecommunications interoperability.

Proxy-Call Session Control Function

Abbreviation for peak-to-average ratio.

Point-to-Multipoint

1. point-to-point,
2. peer-to-peer.

Abbreviation for private automatic branch exchange. See PBX. Note: Use of the term “PBX” is more common than “PABX,” regardless of automation.

1. In data communication, a sequence of binary digits, including data and control signals, that is transmitted and switched as a composite whole. Note: The data, control signals, and possibly error control information, are arranged in a specific format.
2. The fundamental unit of communication on the Internet.

A functional unit that enables data terminal equipment (DTE) not equipped for packet switching to access a packet-switched network.

A packet layer reference event that corresponds to a packet entering a network section (from a circuit section) or a packet entering a DTE (from an access circuit section). [T1.504-1989]

A packet layer reference event that corresponds to a packet exiting a network section (to a circuit section) or a packet exiting a DTE (to an access circuit section). [T1.504-1989]