Computer networks

Main article: Link aggregation

In computer networking, trunking defines using multiple network cables or ports in parallel to increase the link speed beyond the limits of any one single cable or port. This is called port trunking or link aggregation. Trunks may be used to interconnect switches, such as major, minor, public and private switches, to form networks. Link aggregation is a computer networking term which describes using multiple Ethernet network cables/ports in parallel to increase the link speed beyond the limits of any one single cable or port. ... This article or section is in need of attention from an expert on the subject. ... This article or section does not adequately cite its references or sources. ... Ports on the Apple iBook (Early 2003) In computer hardware, a port serves as an interface between the computer and other computers or devices in the form of an electrically wired outlet on a piece of equipment into which a plug or cable connects. ... Link aggregation is a computer networking term which describes using multiple Ethernet network cables/ports in parallel to increase the link speed beyond the limits of any one single cable or port. ...

VLANs

In the context of VLANs, the term "trunk" denotes a network link carrying multiple VLANs which are identified by labels (or "tags") inserted into their packets. Trunking protocols like ISL and IEEE 802.1Q are needed to carry the data through the trunk. A virtual LAN, commonly known as a VLAN, is a logically segmented network mapped over physical hardware. ... Cisco Inter-Switch Link (ISL) is a Cisco Systems proprietary protocol that maintains VLAN information as traffic flows between switches and routers, or switches and switches. ... IEEE 802. ...

Telecommunications

In telecommunications, a trunk is one of^[1]: Telecommunication involves the transmission of signals over a distance for the purpose of communication. ...

• In a communications network, a single transmission channel between two points, which are the switching centers or nodes or both. See Trunked radio system.
• A circuit between telephone switchboards or other switching equipment, as distinguished from circuits which extend from telephone exchange switching equipment to individual telephones or information origination/termination equipment.

A telecommunications network is a network of telecommunications links arranged so that messages may be passed from one part of the network to another over multiple links. ... In telecommunications, transmission is the act of transmitting electrical messages (and the associated phenomena of radiant energy that passes through media). ... Channel, in communications (sometimes called communications channel), refers to the medium used to convey information from a sender (or transmitter) to a receiver. ... A switching center is a node in a telecommunications Circuit switching network which is connected to either another switching center and/or to end user devices. ... A trunked radio system is a radio system used to maximize available capacity in a two-way radio system, usually UHF. Groups of users are given a logical talkgroup to share for their communications, rather than a dedicated radio frequency. ... This article or section does not adequately cite its references or sources. ... Telephone switchboard, 1974 A switchboard (also called a manual branch exchange) is a device used to manually connect a group of telephones from one to another or to an outside connection. ... A telephone operator manually connecting calls with patch cables at a telephone switchboard. ... A telephone handset A touch-tone telephone dial Telephone The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device that transmits speech by means of electric signals. ...

Trunk line

When dealing with a PBX, trunk lines are the phone lines coming into the PBX from the telephone provider ^[2]. This differentiates these incoming lines from extension lines that leave the PBX and usually lead to individual phone sets. Trunking saves cost, because there are usually fewer trunk lines than extension lines, since it is unusual in most offices to have all extension lines in use for external calls at once. Trunk lines transmit voice and data in formats such as analog, T1, E1, ISDN or PRI. See illustration here PBX redirects here. ... A telephone extension is an internal telephone line attached to a PBX or Centrex system. ... Digital signal 1 (DS1, also known as T1, sometimes DS-1) is a T-carrier signaling scheme devised by Bell Labs. ... Digital signal 1 (DS1, also known as T1, sometimes DS-1) is a T-carrier signaling scheme devised by Bell Labs. ... ISDN is also short for isosorbide dinitrate Integrated Services Digital Network (ISDN) is a type of circuit switched telephone network system, designed to allow digital (as opposed to analog) transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds, than available with analog... The primary rate interface (PRI) is a telecommunications standard for carrying multiple DS0 voice and data transmissions between two physical locations. ...

Trunk call

In the UK and the Commonwealth countries, a trunk call was a long distance one as opposed to a local call. See Subscriber trunk dialling and Trunk vs Toll. Subscriber trunk dialling (STD) (also known as subscriber toll dialling) is a term for the UK telephone system allowing subscribers to dial trunk calls without operator assistance. ... In the US, under the purview of the Bell System, local telephone calls were free except in a few big cities, and the term toll was adopted for long distance calls because they were subject to a toll. ...

Telephone exchange

Trunking also refers to the connection of switches and circuits within a telephone exchange.^[3] Trunking is closely related to the concept of Grading. Trunking allows a group of inlet switches at the same time. Thus the service provider can provide a lesser number of circuits than might otherwise be required, allowing many users to "share" a smaller number of connections and achieve capacity savings.^[4][5] Electrical switches. ... A telecommunication circuit is defined as follows: The complete path between two terminals over which one-way or two-way communications may be provided. ... A telephone operator manually connecting calls with patch cables at a telephone switchboard. ... // Introduction In telecommunication, the quality of voice service is specified by two measures: The GOS (grade of service) and the QoS (quality of service). ... Lulworth Cove in Dorset, England (Great Britain) A fjord (Lysefjorden) in Norway An inlet is a body of water, usually seawater, which has characteristics of one or more of the following: a bay a cove an estuary a firth a fjord a geo a sea loch a sea lough a... A service provider is an entity that provides services to other entities. ...

Derivation

In the middle 19th century the principal road of India was named Grand Trunk Road. The Grand Trunk Railway in Canada was named in 1852, long before any telephone cable. From an early stage in the development of telephony, the need was found for thick cables (up to around 10 cm diameter) containing many pairs of wires. These were usually covered in lead. Thus, both in colour and size they resembled an elephant's trunk. Also, since telephone trunks, trunk railways, and trunk roads connect branch offices or branch roads, they act much like the trunk of a tree. The Grand Trunk Road (abbreviated to GT Road in common usage) is one of South Asias oldest and longest major roads. ... 1885 map The Grand Trunk Railway (GTR) was a historic railway system which operated in the Canadian provinces of Quebec and Ontario, as well as the American states of Maine, New Hampshire, and Vermont. ... Genera and Species Loxodonta Loxodonta cyclotis Loxodonta africana Elephas Elephas maximus Elephas antiquus † Elephas beyeri † Elephas celebensis † Elephas cypriotes † Elephas ekorensis † Elephas falconeri † Elephas iolensis † Elephas planifrons † Elephas platycephalus † Elephas recki † Stegodon † Mammuthus † Elephantidae (the elephants) is a family of pachyderm, and the only remaining family in the order Proboscidea... A Private Branch eXchange (PBX) is a telephone exchange that serves a particular business or office, as opposed to one that a common carrier or telephone company operates for many businesses or for the general public. ... Trunk may be: Look up trunk in Wiktionary, the free dictionary. ... The coniferous Coast Redwood, the tallest tree species on earth. ...

References

1. ^ From the Federal Standard 1037C and from MIL-STD-188 and from the Code of Federal Regulations, Telecommunications Parts 0-199
2. ^ Versadial, Call recording encyclopedia, last accessed 18 Apr 2007
3. ^ Flood, J.E., Telecommunications Switching, Traffic and Networks Chapter 4: Telecommunications Traffic. New York: Prentice-Hall, 1998.
4. ^ Motorola, Trunking Communications Overview, last accessed 13 February 2005.
5. ^ The Genesis Group, Trunking Basics, last accessed 13 February 2005.