Packet Switching
05 Jun 2006
A means of economically sending and receiving data over alternate, multiple network channels. The premise for packet switching is the packet, a small bundle of information containing the payload and routing information. Packet switching takes data, breaks it down into packets, transmits the packets and does the reverse on the other end. Packets can be sent in order and then be received in a different order - only to be put back in the correct order in seconds. There are slow packet switching networks, like the old SNA networks - and there are fast packet networks based on Frame Relay and ATM. Although traditionally used for data, packet networks, especially well-managed ones, are becoming suitable for real-time transmission of voice and video.
PBX (Private Branch Exchange) Or PABX (Private Automatic Branch Exchange)
05 Jun 2006
In telephony, a PBX system behaves as a customer's premises over trunk lines (thus the term "branch"). At first, PBXs mimicked a small telephone company switchboard. Users would use an operator to take and make telephone calls to and from the PSTN (Public Switched Telephone Network). Over time, users were able to dial directly, without the use of an operator. Today, computer telephony platforms such as automated attendants are able to route incoming calls automatically, too.
POP (Point of Presence)
05 Jun 2006
Equivalent of a local phone company's central office. The place your long distance carrier terminates your long distance lines just before those lines are connected to your local phone company's lines, or to your own direct hookup.
Alternate Definition: Post Office Protocol. An Internet standard for the storage and retrieval of email messages.
POTS (Plain Old Telephone System)
05 Jun 2006
The standard telephone service that most homes use.
PSTN (Public Switched Telephone Network)
05 Jun 2006
The international telephone system based on copper wires carrying analog voice data.
QOS (Quality of Service)
05 Jun 2006
A networking term that specifies a guaranteed throughput level.
RJ-11
05 Jun 2006
The designation for connecting a tip and ring circuit to a standard, modular, six-position jack. The green and red wires go in the middle (only) pair, and the outside positions of the connector are unused.
RJ-45
05 Jun 2006
Eight-position modular connector used for data transmission over standard twisted or flat pairs.
Router
05 Jun 2006
A device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISPs network. Routers are located at gateways, the places where two or more networks connect. They can be either hardware-based e.g. Netgear, Linksys or software-based e.g. ipcop, smoothwall.
RTP (Real-Time Transport Protocol)
05 Jun 2006
Commonly used with IP networks. RTP is designed to provide end-to-end network transport functions for applications transmitting real-time data, such as audio, video, or simulation data, over multicast or unicast network services. RTP provides such services as payload type identification, sequence numbering, time stamping, and delivery monitoring to real-time applications.