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Trunking
In telecommunications, trunking is a technology for providing network access to multiple clients simultaneously by sharing a set of circuits, carriers, channels, or frequencies, instead of providing individual circuits or channels for each client. This is reminiscent to the structure of a tree with one trunk and many branches. Trunking in telecommunication originated in telegraphy, and later in telephone systems where a trunk line is a communications channel between telephone exchanges. Other applications include the trunked radio systems commonly used by police agencies. In the form of link aggregation and VLAN tagging, trunking has been applied in computer networking. Telecommunications A trunk line is a circuit connecting telephone switchboards (or other switching equipment), as distinguished from local loop circuit which extends from telephone exchange switching equipment to individual telephones or information origination/termination equipment. Trunk lines a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port Trunking
In computer networking, link aggregation is the combining ( aggregating) of multiple network connections in parallel by any of several methods, in order to increase throughput beyond what a single connection could sustain, to provide redundancy in case one of the links should fail, or both. A link aggregation group (LAG) is the combined collection of physical ports. Other umbrella terms used to describe the concept include trunking, bundling, bonding, channeling or teaming. Implementation may follow vendor-independent standards such as Link Aggregation Control Protocol (LACP) for Ethernet, defined in IEEE 802.1AX or the previous IEEE 802.3ad, but also proprietary protocols. Motivation Link aggregation increases the bandwidth and resilience of Ethernet connections. Bandwidth requirements do not scale linearly. Ethernet bandwidths historically have increased tenfold each generation: 10 megabit/s, 100 Mbit/s, 1000 Mbit/s, 10,000 Mbit/s. If one started to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Link Aggregation
In computer networking, link aggregation is the combining ( aggregating) of multiple network connections in parallel by any of several methods, in order to increase throughput beyond what a single connection could sustain, to provide redundancy in case one of the links should fail, or both. A link aggregation group (LAG) is the combined collection of physical ports. Other umbrella terms used to describe the concept include trunking, bundling, bonding, channeling or teaming. Implementation may follow vendor-independent standards such as Link Aggregation Control Protocol (LACP) for Ethernet, defined in IEEE 802.1AX or the previous IEEE 802.3ad, but also proprietary protocols. Motivation Link aggregation increases the bandwidth and resilience of Ethernet connections. Bandwidth requirements do not scale linearly. Ethernet bandwidths historically have increased tenfold each generation: 10 megabit/s, 100 Mbit/s, 1000 Mbit/s, 10,000 Mbit/s. If one started to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIP Trunking
SIP trunking is a voice over Internet Protocol (VoIP) technology and streaming media service based on the Session Initiation Protocol (SIP) by which Internet telephony service providers (ITSPs) deliver telephone services and unified communications to customers equipped with SIP-based private branch exchange (IP-PBX) and unified communications facilities. Most unified communications applications provide voice, video, and other streaming media applications such as desktop sharing, web conferencing, and shared whiteboard. Domains The architecture of SIP trunking provides a partitioning of the unified communications network into two different domains of expertise: * Private domain: refers to a part of the network connected to a PBX or unified communications server. * Public domain: refers to the part of the network which allows access into the public switched telephone network (PSTN) or public land mobile network (PLMN). The interconnection between the two domains must occur through a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VLAN
A virtual local area network (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2).IEEE 802.1Q-2011, ''1.4 VLAN aims and benefits'' In this context, virtual, refers to a physical object recreated and altered by additional logic, within the local area network. VLANs work by applying tags to network frames and handling these tags in networking systems – creating the appearance and functionality of network traffic that is physically on a single network but acts as if it is split between separate networks. In this way, VLANs can keep network applications separate despite being connected to the same physical network, and without requiring multiple sets of cabling and networking devices to be deployed. VLANs allow network administrators to group hosts together even if the hosts are not directly connected to the same network switch. Because VLAN membership can be configured through software, this can greatly simp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunked Radio System
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a ''talkgroup'') with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time talking. These systems typically have access to multiple channels, up to 40-60, so multiple groups in the same area can communicate simultaneously. In a conventional (non-trunked) system, channel selection is done manually; before use the group must decide which channel to use, and manually switch all the radios to that channel. This is an inefficient use of scarce radio channel resources because the user group must have exclusive use of their channel regardless of how much or how little they are transmitting. There is also nothing to prevent multiple groups in the same area from choosing the same channel, causing conflicts and 'cross-talk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VLAN Tagging
IEEE 802.1Q, often referred to as Dot1q, is the computer network, networking standard that supports virtual local area networking (VLANs) on an IEEE 802.3 Ethernet network. The standard defines a system of VLAN tagging for Ethernet frames and the accompanying procedures to be used by Network bridge, bridges and Network switch, switches in handling such frames. The standard also contains provisions for a quality of service, quality-of-service prioritization scheme commonly known as IEEE 802.1p and defines the Generic Attribute Registration Protocol. Portions of the network which are VLAN-aware (i.e., IEEE 802.1Q conformant) can include VLAN tags. When a frame enters the VLAN-aware portion of the network, a tag is added to represent the VLAN membership. Each frame must be distinguishable as being within exactly one VLAN. A frame in the VLAN-aware portion of the network that does not contain a VLAN tag is assumed to be flowing on the native VLAN. The standard was developed by IEEE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. Often, a ''central office'' is defined as a building used to house the inside plant equipment of potentially several telephone exchanges, each serving a certain geographical area. Such an area has also been referred to as the exchange or exchange area. In North America, a central office location may also be identified as a ''wire center'', designating a facility to which a telephone is connected and obtains dial tone. For business and billing purposes, telecommunication carriers def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunication Circuit
A telecommunication circuit is a path in a telecommunications network used to transmit information. Circuits have evolved over time from generally being built on physical connections between individual hardware cables, as in an analog phone switch, to virtual circuits established over packet switching networks. Definitions A telecommunication circuit may be defined as follows: * The complete path between two terminals over which one-way or two-way communications may be provided. * An electronic path between two or more points, capable of providing a single or multiple communication channels. * An electronic closed-loop path among two or more points used for signal transfer. In operational terms, a telecommunication circuit may be capable of transmitting information in only one direction (''simplex'' circuit), or it may be bi-directional (''duplex'' circuit). Bi-directional circuits may support half- duplex operation, when only one end of the channel transmits at any one tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long-distance Calling
In telecommunications, a long-distance call (U.S.) or trunk call (also known as a toll call in the U.K. ) is a telephone call made to a location outside a defined local calling area. Long-distance calls are typically charged a higher billing rate than local calls. The term is not necessarily synonymous with placing calls to another telephone area code. Long-distance calls are classified into two categories: national or domestic calls which connect two points within the same country, and international calls which connect two points in different countries. Within the United States there is a further division into long-distance calls within a single state (intrastate) and interstate calls, which are subject to different regulations (counter-intuitively, calls within states are usually more expensive than interstate calls). Not all interstate calls are long-distance calls. Since 1984 there has also been a distinction between intra- local access and transport area (LATA) calls and thos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Call
In telephony, the term local call has the following meanings: # Any call using a single switching center; that is, not traveling to another telephone network; # A call made within a local calling area as defined by the local exchange carrier; # Any call for which an additional charge, ''i.e.'', toll charge, is not billed to the calling or called party, or (depending on the country) for which this charge is reduced because it is a short-distance call (e.g. within a town or local metropolitan area). Typically, local calls have shorter numbers than long-distance calls, as the area code may not be required. However, this is not true in parts of the United States and Canada that are subject to overlay plans or many countries in Europe that require closed dialing plans. Toll free (e.g. "800" numbers in the United States) are not necessarily local calls; despite being free to the caller, any charge due for the distance of the connection is charged to the ''called'' party. Commercial u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow. Switches are made in many different configurations; they may have multiple sets of contacts controlled by the same knob or actuator, and the contacts may operate simultaneously, sequentially, or alternately. A switch may be operated manually, for example, a light switch or a keyboard button, or may function as a sensing element to sense the position of a machine part, liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as the toggle swi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunication
Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field. The transmission media in telecommunication have evolved through numerous stages of technology, from beacons and other visual signals (such as smoke signals, semaphore telegraphs, signal flags, and optical heliographs), to electrical cable and electromagnetic radiation, including light. Such transmission paths are often divided into communication channels, which afford the advantages of multiplexing multiple concurrent communication sessions. ''Telecommunication'' is often used in its plural form. Other examples of pre-modern long-distance communication included audio messages, such as code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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