packet switch


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Related to packet switch: Packet switched network

packet switch

packet switching

A digital network technology that breaks up a message into smaller chunks (packets) for transmission. Unlike circuit switching in traditional telephone networks, which requires the establishment of a dedicated point-to-point connection, each packet in a packet-switched network contains a destination address. Thus, all packets in a single message do not have to travel the same path. As traffic conditions change, they can be dynamically routed via different paths in the network, and they can even arrive out of order. The destination computer reassembles the packets into their proper sequence.

Data, Voice and Video
Packet switching always excelled at handling messages of different lengths, as well as different priorities, providing the attributes for quality of service (QoS) were included in the design of the network. However, packet switching was originally created for data. Today, using the global standard IP protocol (see TCP/IP), packet networks have become the norm for voice and video as well (see IP on Everything).

The First Packet Switches
The first international standard for wide area packet switching networks was X.25, which was defined at a time when circuits were analog and very susceptible to noise. Subsequent packet technologies, such as frame relay, were designed for almost-error-free digital lines.

ATM uses a cell-switching technology that provides the bandwidth-sharing efficiency of packet switching with the guaranteed bandwidth of circuit switching. See X.25, frame relay and ATM. Contrast with circuit switching.


From FDM to TDM to IP
IP-based packet switching has become the transport for nearly everything, including voice and video. For voice conversations especially, analog and digital-based circuit switching waste as much as 75% of the bandwidth due to pauses in speech and one person listening while the other talks.
References in periodicals archive ?
The new packet switches replace existing technology known as circuit switches.
The Packet Switched Streaming Activity Group was formed by the IMTC in order to perform interoperability tests for Packet-Switched Streaming according to 3GPP Technical Specifications 26.233 and 26.234, for delivering/streaming multimedia content over wireless networks.
A packet switched network is made using optical fibre, over copper cables that circuit switched networks use.
Our Service Assured Networking solutions include best-of-breed tools for cyber security and mission-critical communications, as well as for seamless migration to modern packet switched networks and applications.
Once accomplished, voice calls can, in theory, traverse a packet switched network.
Traditionally, voice quality was always tested using large panels of human users to derive a "mean opinion." These measures were later dropped and, in the mid-1990s, standards were developed to automate the testing and measurement of end-to-end voice quality on both circuit and packet switched networks.
In order to prepare for this change, telecommunications networks should upgrade their circuit switches to packet switches, which can more effectively handle high-speed data, Technology Futures advises.
An X.25 packet switched network that supports the Open Systems Interconnection Standard, the New Network provides telecommunications service to nearly 14,000 OCLC-participating libraries in 46 countries.
Over the long term, all kinds of circuit and packet switched data will be carried over Sonet at DS4 speeds.
The SDN facility at University of Essex comprises packet switches and application servers that can be dynamically connected by optical lightpaths.
They cover the architecture of the present and future Internet, IP address lookup, packet classification (including geometric algorithms), traffic management (including differentiated service and packet scheduling), basics of packet switching, shared-memory switches, input-buffered switches, Banyan-based switches, knockout-based switches, the abacus switch, crosspoint-buffered switches, CLOS-network switches, multi-plane buffered switches, load-balanced switches, optical packet switches, and the high-speed router chip set.
As part of the agreement, Nokia will deliver a WCDMA 3G radio network including the Nokia High Speed Downlink Packet Access (HSDPA) solution, a 3G upgrade to the existing circuit and packet switched networks, and related services.