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34-418: The MVIP (Multi-Vendor Integration Protocol) is a technology used in the construction of call center equipment utilizing standard PCs. It provides a secondary communications bus within the computer, capable of multiplexing up to 256 full-duplex voice channels, which enables the transfer of voice data between different voice cards. Digital voice, fax, and video data are transmitted over a ribbon cable connected at

68-447: A payload of data over a communications network requires sending more than just the payload itself. It also involves sending various control and signalling data ( TCP ) required to reach the destination. This creates a so-called protocol overhead as the additional data does not contribute to the intrinsic meaning of the message. In telephony , number dialing and call set-up time are overheads. In two-way (but half-duplex ) radios,

102-544: A big financial incentive to do so. Often, even though software providers are well aware of bugs in their products, the payoff of fixing them is not worth the reward, because of the overhead. For example, an implicit data structure or succinct data structure may provide low space overhead, but at the cost of slow performance (space/time tradeoff). Algorithmic complexity is generally specified using Big O notation . This makes no comment on how long something takes to run or how much memory it uses, but how its increase depends on

136-421: A choice of several algorithms , encodings , data types or data structures , each of which have known characteristics. When choosing among them, their respective overhead should also be considered. In software engineering , overhead can influence the decision whether or not to include features in new products, or indeed whether to fix bugs. A feature that has a high overhead may not be included – or needs

170-610: A data or framing pattern that reports the far end is in "red alarm". The alarm is carried differently in SF (D4) and ESF (D5) framing. For SF framed signals, the user bandwidth is manipulated and "bit two in every DS0 channel shall be a zero." The resulting loss of payload data while transmitting a yellow alarm is undesirable, and was resolved in ESF framed signals by using the data link layer . "A repeating 16-bit pattern consisting of eight 'ones' followed by eight 'zeros' shall be transmitted continuously on

204-453: A framing bit (for frame synchronization ) and a maintenance-signaling bit, transmitted over a digital circuit called T1 . T1 's maximum data transmission rate is 1.544 megabits per second. A DS1 telecommunication circuit multiplexes 24 DS0s . The twenty-four DS0s sampled 8,000 times per second (one 8bit PCM sample from each DSO per DS1 frame) consume 1.536 Mbit/s of bandwidth . One framing bit adds 8 kbit/s of overhead, for

238-428: A request for response. Inband T1s are also capable of carrying CID and ANI information if they are configured by the carrier by sending DTMF *ANI*DNIS*. However, PRIs handle this more efficiently. While an inband T1 seemingly has a slight advantage due to 24 lines being available to make calls (as opposed to a PRI that has 23), each channel in an inband T1 must perform its own setup and tear-down of each call. A PRI uses

272-418: A small run-time overhead. Sometimes the compiler can minimize this overhead by inlining some of these function calls . In a CPU cache , the "cache size" (or capacity ) refers to how much data a cache stores. For instance, a "4 KB cache" is a cache that holds 4 KB of data. The "4 KB" in this example excludes overhead bits such as frame, address, and tag information. Reliably sending

306-400: A total of 1.544 Mbit/s, calculated as follows: DS1 is a full-duplex circuit, concurrently transmitting and receiving 1.544 Mbit/s . Frame synchronization is necessary to identify the timeslots within each 24-channel frame. Synchronization takes place by allocating a framing, or 193rd, bit. This results in 8 kbit/s of framing data, for each DS1. Because this 8-kbit/s channel

340-532: Is a T-carrier signaling scheme devised by Bell Labs . DS1 is the primary digital telephone standard used in the United States , Canada and Japan and is able to transmit up to 24 multiplexed voice and data calls over telephone lines. E-carrier is used in place of T-carrier outside the United States, Canada, Japan, and South Korea. DS1 is the logical bit pattern used over a physical T1 line; in practice,

374-742: Is a technology with roots in the 60's and before. The name T1 came from the carrier letter assigned by AT&T to the technology in 1957, when digital systems were first proposed and developed, AT&T decided to skip Q, R, and S, and to use T, for time division . The naming system ended with the letter T, which designated fiber networks. Destined successors of the T1 system of networks, called T1C , T2 , T3 , and T4 , were not commercial successes and disappeared quickly. Signals that would have been carried on these systems, called DS1 , DS2 , DS3 , and DS4 , are now carried on T1 infrastructure. DS-1 means Digital Service – Level 1 and has to do with

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408-709: Is thus similar to overhead in organizations. Computer system overhead shows up as slower processing, less memory, less storage capacity, less network bandwidth, or bigger latency than would be expected from reading the system specifications. It is a special case of engineering overhead . Overhead can be a deciding factor in software design, with regard to structure, error correction, and feature inclusion. Examples of computing overhead may be found in Object Oriented Programming (OOP), functional programming , data transfer, data structures, and file systems on data storage devices. A programmer/software engineer may have

442-571: Is used by the transmitting equipment as overhead , only 1.536 Mbit/s is actually passed on to the user. Two types of framing schemes are superframe (SF) and extended superframe (ESF). A superframe consists of twelve consecutive 193-bit frames, whereas an extended superframe consists of twenty-four consecutive 193-bit frames of data. Due to the unique bit sequences exchanged, the framing schemes are not compatible with each other. These two types of framing (SF, and ESF) use their 8 kbit/s framing channel in different ways. Connectivity refers to

476-429: The 23 actual usable telephone lines (known as B channels for bearer ) but also a 24th line (known as the D channel for data ) that carries line signaling information. This special D channel carries: Caller ID (CID) and automatic number identification (ANI) data, required channel type (usually a B, or bearer, channel), call handle, Dialed Number Identification Service (DNIS) info, requested channel number and

510-447: The 24th channel as a data channel to perform all the overhead operations of the other 23 channels (including CID and ANI). Although an inband T1 has 24 channels, the 23 channel PRI can set up more calls faster due to the dedicated 24th signalling channel (D Channel). Before T1 PRI existed there was T1 CAS. T1 CAS is not common today but it still exists. CAS is Channel Associated Signaling. It is also referred to as Robbed Bit Signaling. CAS

544-436: The 32-bit signed integer 1310447927 , consuming only 4 bytes. Represented as ISO 8601 formatted UTF-8 encoded string 2011-07-12 07:18:47 the date would consume 19 bytes, a size overhead of 375% over the binary integer representation. As XML this date can be written as follows with an overhead of 218 characters, while adding the semantic context that it is a CHANGEDATE with index 1. The 349 bytes, resulting from

578-399: The ESF data link, but may be interrupted for a period not to exceed 100-ms per interruption." Both types of alarms are transmitted for the duration of the alarm condition, but for at least one second. Blue alarm , also known as alarm indication signal (AIS) indicates a disruption in the communication path between the terminal equipment and line repeaters or DCS . If no signal is received by

612-460: The UTF-8 encoded XML, correlates to a size overhead of 8625% over the original integer representation. Besides the files themselves, computer file systems take a portion of the space to store directory names and listings, file names, files' sector locations, attributes such as the date and time of the last modification and creation, how the files are fragmented , written and free parts of the space, and

646-461: The ability of the digital carrier to carry customer data from either end to the other. In some cases, the connectivity may be lost in one direction and maintained in the other. In all cases, the terminal equipment, i.e., the equipment that marks the endpoints of the DS1, defines the connection by the quality of the received framing pattern. Alarms are normally produced by the receiving terminal equipment when

680-437: The adoption of IEEE standards for gigabit Ethernet and 10 Gigabit Ethernet over single-mode fiber. Running Ethernet networks between geographically separated buildings is a practice known as " WAN elimination". DS1C is a digital signal equivalent to two Digital Signal 1 circuits, with extra bits to conform to a signaling standard of 3.152 Mbit/s. Few (if any) of these circuit capacities are still in use today. In

714-524: The alarmed equipment. Simultaneously, the customer data is often coerced to a 0x7F pattern, signifying a zero-voltage condition on voice equipment. Data equipment usually passes whatever data may be present, if any, leaving it to the customer equipment to deal with the condition. Additionally, for voice T1s there are two main types: so-called "plain" or Inband T1s and PRI ( Primary Rate Interface ). While both carry voice telephone calls in similar fashion, PRIs are commonly used in call centers and provide not only

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748-450: The bus, allowing for a flexible routing of calls within the MVIP bus. The MVIP bus was promoted as an alternative to the then-dominant PEB bus by Dialogic Corporation which had much less capacity and was not an open standard. This computer hardware article is a stub . You can help Misplaced Pages by expanding it . Digital Signal 1 Digital Signal 1 ( DS1 , sometimes DS-1 )

782-484: The early days of digital and data transmission, the three-megabit-per-second data rate was used to link mainframe computers together. The physical side of this circuit is called T1C. The T1/E1 protocol is implemented as a "line interface unit" in silicon. The semiconductor chip contains a decoder/encoder, loop backs, jitter attenuators, receivers, and drivers. Additionally, there are usually multiple interfaces and they are labeled as dual, quad, octal, etc., depending upon

816-495: The framing is compromised. There are three defined alarm indication signal states, identified by a legacy color scheme: red, yellow and blue. Red alarm indicates the alarming equipment is unable to recover the framing reliably. Corruption or loss of the signal will produce "red alarm". Connectivity has been lost toward the alarming equipment. There is no knowledge of connectivity toward the far end. Yellow alarm , also known as remote alarm indication (RAI), indicates reception of

850-405: The intermediary equipment, it produces an unframed, all-ones signal. The receiving equipment displays a "red alarm" and sends the signal for "yellow alarm" to the far end because it has no framing, but at intermediary interfaces the equipment will report "AIS" or Alarm Indication Signal . AIS is also called "all ones" because of the data and framing pattern. These alarm states are also lumped under

884-519: The number. The transceiver chip's primary purpose is to retrieve information from the "line", i.e., the conductive line that transverses distance, by receiving the pulses and converting the signal which has been subjected to noise, jitter , and other interference, to a clean digital pulse on the other interface of the chip. Overhead information Overhead in computer systems consists of shared functions that benefit all users or processes but are not directly attributable to any specific task. It

918-411: The rate of 1.544 Mbit/s. The type of line code used is called Alternate Mark Inversion (AMI). Digital Signal Designation is the classification of digital bit rates in the digital multiplex hierarchy used in transport of telephone signals from one location to another. DS-1 is a communications protocol for multiplexing the bitstreams of up to 24 telephone calls, along with two special bits :

952-525: The signal carried—as opposed to the network that delivers it (originally 24 digitized voice channels over a T1). Since the practice of naming networks ended with the letter T , the terms T1 and DS1 have become synonymous and encompass a variety of services including voice, data, and clear-channel pipes . The line speed is always 1.544 Mbit/s, but the payload can vary greatly. Dark fiber : Dark fiber refers to unused fibers available for use. Dark fiber has been, and still is, available for sale on

986-405: The size of the input. Overhead is deliberately not part of this calculation, since it varies from one machine to another, whereas the fundamental running time of an algorithm does not. This should be contrasted with algorithmic efficiency , which takes into account all kinds of resources – a combination (though not a trivial one) of complexity and overhead. Invoking a function introduces

1020-453: The term Carrier Group Alarm (CGA). The meaning of CGA is that connectivity on the digital carrier has failed. The result of the CGA condition varies depending on the equipment function. Voice equipment typically coerces the robbed bits for signaling to a state that will result in the far end properly handling the condition, while applying an often different state to the customer equipment connected to

1054-515: The terms DS1 and T1 are often used interchangeably. T1 refers to the primary digital telephone carrier system used in North America. T1 is one line type of the PCM T-carrier hierarchy. T1 describes the cabling, signal type, and signal regeneration requirements of the carrier system. The signal transmitted on a T1 line, referred to as the DS1 signal, consists of serial bits transmitted at

Multi-Vendor Integration Protocol - Misplaced Pages Continue

1088-413: The top of each ISA or PCI card. MVIP technology allows a PC to function similarly to a small-scale private branch exchange (PBX) system. The protocol accommodated for a variety of expansion boards, including trunk interfaces (usually T1 or ISDN ), voice processing boards equipment speech recognition or fax processing. Each board could optionally provide a switch that could interconnect voice channels on

1122-399: The use of "over" and other signaling needed to avoid collisions is an overhead. Protocol overhead can be expressed as a percentage of non-application bytes (protocol and frame synchronization ) divided by the total number of bytes in the message. The encoding of information and data introduces overhead too. The date and time "2011-07-12 07:18:47" can be expressed as Unix time with

1156-408: The wholesale market for both metro and wide area links, but it may not be available in all markets or city pairs. Dark fiber capacity is typically used by network operators to build SONET and dense wavelength-division multiplexing (DWDM) networks, usually involving meshes of self-healing rings . Now, it is also used by end-user enterprises to expand Ethernet local area networks, especially since

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