ISDN - Knowledge

606:' seminal work on digital encoding of voice led to the use of 64 kbit/s as a standard for voice lines (or 56 kbit/s in some systems). In 1962, Robert Aaron of Bell introduced the T1 system, which carried 1.544 Mbit/s of data on a pair of twisted pair lines over a distance of about one mile. This was used in the Bell network to carry traffic between local switch offices, with 24 voice lines at 64 kbit/s and a separate 8 kbit/s line for signaling commands like connecting or hanging up a call. This could be extended over long distances using repeaters in the lines. T1 used a very simple encoding scheme, 1015: 4420: 1550: 4430: 864:, and one D channel with a bandwidth of 16 kbit/s. Together these three channels can be designated as 2B+D. Primary Rate Interface (PRI), also called primary rate access (PRA) in Europe — contains a greater number of B channels and a D channel with a bandwidth of 64 kbit/s. The number of B channels for PRI varies according to the nation: in North America and Japan it is 23B+1D, with an aggregate bit rate of 1.544 4409: 1760:, ranging up from 64 kbit/s up to 1.0 Mbit/s, the 2006 OECD report is typical by defining broadband as having download data transfer rates equal to or faster than 256 kbit/s, while the United States FCC, as of 2008, defines broadband as anything above 768 kbit/s. Once the term "broadband" came to be associated with data rates incoming to the customer at 256 kbit/s or more, and alternatives like 499: 4440: 656:, but at the much higher bandwidth of the new concept, this would not be so simple. A debate broke out between teams worldwide about the best solution to this problem; some promoted newer versions of echo cancellation, while others preferred the "ping pong" concept where the direction of data would rapidly switch the line from send to receive at such a high rate it would not be noticeable to the user. 532:"Red Book". By the time the standard was released, newer networking systems with much greater speeds were available, and ISDN saw relatively little uptake in the wider market. One estimate suggests ISDN use peaked at a worldwide total of 25 million subscribers at a time when 1.3 billion analog lines were in use. ISDN has largely been replaced with 1006:(CPE) and must be maintained by the customer, thus, the U interface is provided to the customer. In other locations, the NT1 device is maintained by the telco, and the S/T interface is provided to the customer. In India, service providers provide U interface and an NT1 may be supplied by Service provider as part of service offering. 626:" was increasingly seen as the next problem that needed to be solved. However, these connections now represented over 99% of the total telephony network, as the upstream links had increasingly been aggregated into a smaller number of much higher performance systems, especially after the introduction of 1627:

are the largest communication service providers, and offer both ISDN BRI and PRI services across the country. Reliance Communications and Bharti Airtel uses the DLC technology for providing these services. With the introduction of broadband technology, the load on bandwidth is being absorbed by ADSL.

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offers ISDN services under their product name Numeris (2 B+D), of which a professional Duo and home Itoo version is available. ISDN is generally known as RNIS in France and has widespread availability. The introduction of ADSL is reducing ISDN use for data transfer and Internet access, although it is

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were normally 300 bit/s and 1200 bit/s would not become common until the early 1980s and the 2400 bit/s standard would not be completed until 1984. In this market, 16 kbit/s represented a significant advance in performance in addition to being a separate channel that coexists with

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Since approximately 2010, most German operators have offered more and more VoIP on top of DSL lines and ceased offering ISDN lines. New ISDN lines have been no longer available in Germany since 2018, existing ISDN lines were phased out from 2016 onwards and existing customers were encouraged to move

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provides the business customer with the ISDN services. There are five types of ISDN services which are ISDN2, ISDN2 Enhanced, ISDN10, ISDN20 and ISDN30. Telstra changed the minimum monthly charge for voice and data calls. In general, there are two group of ISDN service types; The Basic Rate services

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Meanwhile, the debate over the encoding scheme itself was also ongoing. As the new standard was to be international, this was even more contentious as several regional digital standards had emerged in the 1960s and 70s and merging them was not going to be easy. To further confuse issues, in 1984 the

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or by providing a T1 on the customer's location. What became ISDN started as an effort to digitize the last mile, originally under the name "Public Switched Digital Capacity" (PSDC). This would allow call routing to be completed in an all-digital system, while also offering a separate data line. The

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Although ISDN was successful in a few countries such as Germany, on a global scale the system was largely ignored and garnered the industry nickname "innovation subscribers didn't need." It found a use for a time for small-office digital connection, using the voice lines for data at 64 kbit/s,

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ISDN-BRI never gained popularity as a general use telephone access technology in Canada and the US, and remains a niche product. The service was seen as "a solution in search of a problem", and the extensive array of options and features were difficult for customers to understand and use. ISDN has

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can be carried over the B or D channels of a BRI line, and over the B channels of a PRI line. X.25 over the D channel is used at many point-of-sale (credit card) terminals because it eliminates the modem setup, and because it connects to the central system over a B channel, thereby eliminating the

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broke out, but in 1991 Lechleider's 1.6 Mbit/s "High-Speed Digital Subscriber Line" eventually won this process as well, after Starr drove it through the ANSI T1E1.4 group. A similar standard emerged in Europe to replace their E1 lines, increasing the sampling range from 80 to 100 kHz to

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With digital-quality voice made possible by ISDN, offering two separate lines and continuous data connectivity, there was an initial global expectation of high customer demand for such systems in both the home and office environments. This expectation was met with varying degrees of success across

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were often bundled on the same line, mainly because the combination of DSL with an analog line had no cost advantage over a combined ISDN-DSL line. This practice turned into an issue for the operators when vendors of ISDN technology stopped manufacturing it and spare parts became hard to come by.

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provided performance around 10 Mbit/s which had become the baseline for inter-computer connections in offices. ISDN offered no real advantages in the voice role and was far from competitive in data. Additionally, modems had continued improving, introducing 9600 bit/s systems in the late

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hardware can bond up to 8 B-channels together (using a BRI circuit for every 2 channels) to provide digital, circuit-switched video connections to almost anywhere in the world. This is very expensive, and is being replaced by IP-based conferencing, but where cost concern is less of an issue than

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had recently demonstrated echo cancellation would work at these speeds, and further suggested that they should consider moving directly to 1.5 Mbit/s performance using this concept. The suggestion was literally laughed off the table (His boss told him to "sit down and shut up") but the echo

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encoding technique, call data is transmitted over the data (B) channels, with the signaling (D) channels used for call setup and management. Once a call is set up, there is a simple 64 kbit/s synchronous bidirectional data channel (actually implemented as two simplex channels, one in each

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began one such effort to develop a last-mile solution. They studied a number of derivatives of the T1's AMI concept and concluded that a customer-side line could reliably carry about 160 kbit/s of data over a distance of 4 to 5 miles (6.4 to 8.0 km). That would be enough to carry two

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known as "NEXT", for "near-end crosstalk". This made longer connections on customer lines difficult. Lechleider noted that NEXT only occurred when similar frequencies were being used, and could be diminished if one of the directions used a different carrier rate, but doing so would reduce the

1521:– ISDN 2 or ISDN 2 Enhanced. Another group of types are the Primary Rate services, ISDN 10/20/30. Telstra announced that the new sales of ISDN product would be unavailable as of 31 January 2018. The final exit date of ISDN service and migration to the new service would be confirmed by 2022. 685:. This standard used an 80 kHz base frequency and encoded two bits per baud to produce the 160 kbit/s base rate. Ultimately Japan selected a different standard, and Germany selected one with three levels instead of four, but all of these could interchange with the ANSI standard. 744:

Conversely, in Europe, ISDN found fertile ground for deployment, driven by regulatory support, infrastructural needs, and the absence of comparable high-speed communication technologies at the time. The technology was widely embraced for its ability to digitalize the "last mile" of

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algorithm is used with a single 64 kbit/s B channel to send much lower latency mono audio at the expense of audio quality. Where very high quality audio is required multiple ISDN BRIs can be used in parallel to provide a higher bandwidth circuit switched connection.

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A key problem was that the customer might only have a single twisted pair line to the location of the handset, so the solution used in T1 with separate upstream and downstream connections was not universally available. With analog connections, the solution was to use

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copper line has been installed for telephone use worldwide, with well over a billion individual connections installed by the year 2000. Over the first half of the 20th century, the connection of these lines to form calls was increasingly automated, culminating in the

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Previously, in April 1985, Japanese digital telephone exchange hardware made by Fujitsu was used to experimentally deploy the world's first I interface ISDN. The I interface, unlike the older and incompatible Y interface, is what modern ISDN services use today.

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having given up on it and not providing Internet access using it. However, AT&T in most states (especially the former SBC/SWB territory) will still install an ISDN BRI line anywhere a normal analog line can be placed and the monthly charge is roughly $ 55.

782:, who jumped on ADSL while many other companies were still devoted to ISDN. Krish Prabu stated that "Alcatel will have to invest one billion dollars in ADSL before it makes a profit, but it is worth it." They introduced the first DSL Access Multiplexers ( 1824:, but the director and producer are in a studio at another location. The ISDN protocol delivers channelized, not-over-the-Internet service, powerful call setup and routing features, faster setup and tear down, superior audio fidelity as compared to 727:

In the United States, many changes in the market led to the introduction of ISDN being tepid. During the lengthy standardization process, new concepts rendered the system largely superfluous. In the office, multi-line digital switches like the

1561:, ISDN was very popular with an installed base of 25 million channels (29% of all subscriber lines in Germany as of 2003 and 20% of all ISDN channels worldwide). Due to the success of ISDN, the number of installed analog lines was decreasing. 793:

ADSL quickly replaced ISDN as the customer-facing solution for last-mile connectivity. ISDN has largely disappeared on the customer side, remaining in use only in niche roles like dedicated teleconferencing systems and similar legacy systems.

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to provide a total duplex bandwidth of 128 kbit/s. This precludes use of the line for voice calls while the internet connection is in use. The B channels of several BRIs can be bonded, a typical use is a 384K videoconferencing channel.

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was also part of an ISDN protocol called "Always On/Dynamic ISDN", or AO/DI. This allowed a user to have a constant multi-link PPP connection to the internet over X.25 on the D channel, and brought up one or two B channels as needed.

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In many countries, such as the UK and Australia, ISDN has displaced the older technology of equalised analogue landlines, with these circuits being phased out by telecommunications providers. Use of IP-based streaming codecs such as

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standard was designed around its 64 kbit/s data rate. The underlying ISDN concepts found wider use as a replacement for the T1/E1 lines it was originally intended to extend, roughly doubling the performance of those lines.

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By the late 1970s, T1 lines and their faster counterparts, along with all-digital switching systems, had replaced the earlier analog systems for most of the western world, leaving only the customer's equipment and their local

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potential bandwidth of that channel. Lechleider suggested that most consumer use would be asymmetric anyway, and that providing a high-speed channel towards the user and a lower speed return would be suitable for many uses.

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sockets for direct computer access. Home Highway was bought by many home users, usually for Internet connection, although not as fast as ADSL, because it was available before ADSL and in places where ADSL does not reach.

1565:(DTAG) offered both BRI and PRI. Competing phone companies often offered ISDN only and no analog lines. However, these operators generally offered free hardware that also allows the use of POTS equipment, such as NTBAs (" 1389:

using MPEG or various manufacturers' proprietary algorithms, an ISDN BRI can be used to send stereo bi-directional audio coded at 128 kbit/s with 20 Hz – 20 kHz audio bandwidth, although commonly the

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field, where even small improvements in data rates are useful, but more importantly, its direct end-to-end connection offers lower latency and better reliability than packet-switched networks of the 1990s. The

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began offering nationwide ISDN services trademarked INS Net 64, and INS Net 1500, a fruition of NTT's independent research and trial from the 1970s of what it referred to the INS (Information Network System).

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Meanwhile, Lechleider had proposed using ISDN's echo cancellation and 2B1Q encoding on existing T1 connections so that the distance between repeaters could be doubled to about 2 miles (3.2 km). Another

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H.263 is similar to, but more complex than H.261. It is currently the most widely used international video compression standard for video telephony on ISDN (Integrated Services Digital Network) telephone

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direction) between the end parties, lasting until the call is terminated. There can be as many calls as there are bearer channels, to the same or different end-points. Bearer channels may also be

1768:, BRI has a greater limit and can use repeaters. As such, BRI may be acceptable for customers who are too remote for ADSL. Widespread use of BRI is further stymied by some small North American 908:

into what may be considered single, higher-bandwidth channels via a process called B channel BONDING, or via use of Multi-Link PPP "bundling" or by using an H0, H11, or H12 channel on a PRI.

2118: 817:. Multiple devices can be attached to the line, and used as needed. That means an ISDN line can take care of what were expected to be most people's complete communications needs (apart from 630:

lines. If the system was to become all-digital, a new standard would be needed that was appropriate for the existing customer lines, which might be miles long and of widely varying quality.

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to DSL-based VoIP products. Deutsche Telekom intended to phase-out by 2018 but postponed the date to 2020, other providers like Vodafone estimate to have their phase-out completed by 2022.

1608:. Following the launch of ADSL in 2003, the importance of ISDN for data transfer began to decrease and is today limited to niche business applications with point-to-point requirements. 766:

Lechleider also believed this higher-speed standard would be much more attractive to customers than ISDN had proven. Unfortunately, at these speeds, the systems suffered from a type of

2388: 2923: 564:, or BRI, is the standard last-mile connection in the ISDN system, offering two 64 kbit/s "bearer" lines and a single 16 kbit/s "data" channel for commands and data. 2354: 1399:

commonly makes use of three ISDN BRIs to carry 320 kbit/s audio stream for live outside broadcasts. ISDN BRI services are used to link remote studios, sports grounds and

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ISDN is used heavily by the broadcast industry as a reliable way of switching low-latency, high-quality, long-distance audio circuits. In conjunction with an appropriate

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grew in popularity, the consumer market for BRI did not develop. Its only remaining advantage is that, while ADSL has a functional distance limitation and can use

1407:. ISDN via satellite is used by field reporters around the world. It is also common to use ISDN for the return audio links to remote satellite broadcast vehicles. 825:) at a much higher transmission rate, without forcing the purchase of multiple analog phone lines. It also refers to integrated switching and transmission in that 1716:, which were BRI ISDN-based services that offered integrated analogue connectivity as well as ISDN. Later versions of the Highway products also included built-in 1316:(PSTN) by giving users direct access to end-to-end circuit-switched digital services and as a backup or failsafe circuit solution for critical use data circuits. 982: 860:

There are two ISDN implementations. Basic Rate Interface (BRI), also called basic rate access (BRA) — consists of two B channels, each with bandwidth of 64

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In North America, PRI service is delivered via T1 carriers with only one data channel, often referred to as 23B+D, and a total data rate of 1544 kbit/s.

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is a four-wire bus that ISDN consumer devices plug into; the S & T reference points are commonly implemented as a single interface labeled 'S/T' on a

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Most NT-1 devices can perform the functions of the NT2 as well, and so the S and T reference points are generally collapsed into the S/T reference point.

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tones to encode the destination number. ISDN is much better because messages can be sent much more quickly than by trying to encode numbers as long (100

17: 1808:(CLID) in both directions so that the telephone number of an extension, rather than a company's main number, can be sent. It is still commonly used in 2693: 2325: 1566: 485: 2126: 1250:

can be thought of as a collection of wires strung between switching systems. The common electrical specification for the signals on these wires is

555:". At the time, the network was viewed as a way to transport voice, with some special services available for data using additional equipment like 4474: 2945: 2874: 2746: 1683:

from around 2020 to around 2025. For this migration, ISDN services will be retired, and fiber optic services are recommended as an alternative.

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telecommunications, significantly enhancing the quality and efficiency of voice, data, and video transmission over traditional analog systems.

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A study of the Germany's Federal Ministry of Education and Research shows the following share of ISDN-channels per 1,000 inhabitants in 2005:

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service delivered over a pair of standard telephone copper wires. The 144 kbit/s overall payload rate is divided into two 64 kbit/s

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sometimes "bonded" to 128 kbit/s, but the introduction of 56 kbit/s modems undercut its value in many roles. It also found use in

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per digit) tone sequences. This results in faster call setup times. Also, a greater number of features are available and fraud is reduced.

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to refer to the lower-bandwidth BRI circuit, in North America BRI is relatively uncommon whilst PRI circuits serving PBXs are commonplace.

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BRI-ISDN is very popular in Europe but is much less common in North America. It is also common in Japan — where it is known as INS64.

245: 880:(BISDN) is another ISDN implementation and it is able to manage different types of services at the same time. It is primarily used within 602:

As telephone use surged in the post-WWII era, the problem of connecting the massive number of lines became an area of significant study.

2647: 2178: 3127: 2358: 786:), the large multi-modem systems used at the telephony offices, and later introduced customer ADSL modems under the Thomson brand. 2915: 2297: 4386: 2516: 916: 4381: 4371: 4351: 4153: 2834: 2812: 2778: 2239: 1922: 1100:

defines the point between a non-ISDN device and a terminal adapter (TA) which provides translation to and from such a device.

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ISDN continues to be an important backup network for point-to-point leased line customers such as banks, e-Seva Centers,

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Robin, G; Treves, S (July 1979). "Pragmatic Introduction of Digital Switching and Transmission in Existing Networks".

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Providing a backup line for business's inter-office and internet connectivity was a popular use of the technology.

715:(the European Telecommunications Standards Institute) was created by CEPT in 1988 and would develop the framework. 471: 402: 195: 2410: 4138: 2963:

You may not obtain Internet services over ISDN lines (BRI or PRI), dedicated circuits or special service circuits

1124:(E1) with 32 channels in most other countries. Each channel provides transmission at a 64 kbit/s data rate. 2626: 805:

refers to ISDN's ability to deliver at minimum two simultaneous connections, in any combination of data, voice,

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1980s and 14.4 kbit/s in 1991, which significantly eroded ISDN's value proposition for the home customer.

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The Call Center Dictionary: The Complete Guide to Call Center & Customer Support Technology Solutions

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is becoming more widespread in the broadcast sector, using broadband internet to connect remote studios.

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for telephony, also in an effort to reduce their costs by operating separate data & voice networks.

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encoding. B-channels can also be used to carry data, since they are nothing more than digital channels.

4282: 4204: 4143: 3850: 3329: 3225: 1858: 1836: 1712:(BT) provides ISDN2e (BRI) as well as ISDN30 (PRI). Until April 2006, they also offered services named 1180:

The bearer channel (B) is a standard 64 kbit/s voice channel of 8 bits sampled at 8 kHz with

1150:. D-channel backup allows for a second D channel in case the primary fails. NFAS is commonly used on a 885: 666: 643:

voice-quality lines at 64 kbit/s as well as a separate 16 kbit/s line for data. At the time,

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ISDN-BRI is currently primarily used in industries with specialized and very specific needs. High-end

4054: 4015: 3860: 3760: 3689: 3622: 3449: 3334: 3072: 2951: 2884: 2738: 2264: 1873: 1757: 1362: 1271: 818: 1541:. In 2023, Numeris services will enter a phase-out process. They will be replaced by VoIP services. 1341:

was designed with ISDN in mind, and more specifically its 64 kbit/s basic data rate. including

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Another alternative ISDN configuration can be used in which the B channels of an ISDN BRI line are

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gained greater popularity. On November 2, 2010, NTT announced plans to migrate their backend from

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There is not a single ISDN specification, but mere a collection of various incompatible dialects.

1657: 1620: 1534: 1158: 872:); in Europe, India and Australia it is 30B+2D, with an aggregate bit rate of 2.048 Mbit/s ( 533: 457: 447: 240: 155: 139: 124: 110: 4174: 3960: 3775: 3720: 3715: 3528: 3493: 1113: 935: 755: 325: 175: 2802: 2768: 4076: 3880: 3845: 3765: 3745: 3667: 3555: 3476: 3237: 3150: 1801: 1668: 1350: 1259: 1088: 992: 452: 225: 31: 3409: 2223: 1724:

In early 2015, BT announced their intention to retire the UK's ISDN infrastructure by 2025.

1569:": small devices that bridge the two-wire UK0 line to the four-wire S0 bus) with integrated 919:. In practice, X.31 was only commercially implemented in the UK, France, Japan and Germany. 661:

cancellation concept that was taken up by Joe Lechleider eventually came to win the debate.

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of voice, video, data, and other network services over the digitalised circuits of the

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In Japan, the number of ISDN subscribers dwindled as alternative technologies such as

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IEEE WESCANEX 97: communications, power, and computing : conference proceedings

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ISDN is also used as a smart-network technology intended to add new services to the

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need for modems and making much better use of the central system's telephone lines.

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ISDN, incorporating the "FLET's" brand that NTT uses for all of its ISP offerings.

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on the long-distance lines between telephone company offices and analog signals on

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can operate over the D channel of BRIs and PRIs, but it is seldom, if ever, used.

3900: 3755: 3523: 3498: 3486: 3136: 2319: 2029: 1325: 1294: 1290: 1267: 892: 708: 682: 596: 569: 311: 2119:"Verizon: No Longer Taking Orders for ISDN Service in Northeast Starting May 18" 1585:

Since then phone companies started introducing cheaper xDSL-only products using

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in December 1986 for its coordinated introduction within the framework of CEPT.

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Decina, M; Scace, E (May 1986). "CCITT Recommendations on the ISDN: A Review".

1848: 1705: 1604:, the incumbent telecommunications operator, offers ISDN BRI (BRA) services in 1469: 1202:

lines. This was commonplace in the 20th century, but has since become less so.

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still common in more rural and outlying areas, and for applications such as

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transmission are integrated rather than separate as in earlier technology.

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systems, where a direct end-to-end connection is desirable. ISDN uses the

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data packets, and connection to X.25 packet network, this is specified in

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establishing and breaking circuit-switched connections, and for advanced

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ISDN The Integrated Services Digital Network: Concepts, Methods, Systems

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With the E1 carrier, the available channels are divided into 30 bearer (

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are intended for signaling and control (but can also be used for data).

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kbit/s signal, but some were limited to 56K because they traveled over

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concept, which emerged in 1995. An early supporter of the concept was

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led this effort and eventually convinced the ANSI group to select the

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Although various minimum bandwidths have been used in definitions of

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PRI-ISDN is popular throughout the world, especially for connecting

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remained the primary vendor of ADSL systems for well over a decade.

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Prior to ISDN, the telephone system consisted of digital links like

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with the central office switch, replacing older analog two-way and

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systems, where the direct end-to-end connection was desirable. The

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Published recommendations available in English, French and Spanish

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announced it would no longer take orders for ISDN service in the

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Telecompetition: The Free Market Road to the Information Highway

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Around 1978, Ralph Wyndrum, Barry Bossick and Joe Lechleider of

498: 4335: 4295: 3617: 3314: 3185: 3160: 1863: 1605: 1493: 1481: 1439: 1412: 949: – defines the point between non-ISDN terminal equipment, 865: 861: 391: 285: 184: 164: 3066: 1120:(T1) with 24 time slots (channels) in North America, and over 4320: 4257: 3565: 3349: 3344: 3289: 3273: 3250: 2030:"Telecommunications Law and Policy in the European Community" 1499: 1487: 1463: 1416: 1391: 1386: 1374: 1370: 1354: 1346: 1330: 1298: 1282: 1181: 783: 644: 573: 556: 529: 412: 190: 96: 4262: 3180: 1868: 1793: 1761: 1749:, or, from the supposed standpoint of telephone companies, 1676: 1664: 1586: 1581: 1577: 1358: 1217: 1210: 969: – defines the point between ISDN terminal equipment, 912: 900: 775: 712: 678: 380: 375: 345: 295: 215: 180: 128: 1912: 1828:(POTS), lower delay and, at higher densities, lower cost. 1045:

The interface specifies the following network interfaces:

673:(ANSI) T1D1.3 committee. Thomas Starr of the newly formed 1789:-enabled IP does not exist, BRI is the preferred choice. 1717: 1601: 1188: 1042:

or data channel). This is sometimes referred to as 2B+D.

963:(TA) which provides translation to and from such a device 911:

The D channel can also be used for sending and receiving

810: 599:

that had largely replaced earlier concepts by the 1950s.

200: 1691:

On April 19, 1988, Norwegian telecommunications company

1644:

On April 19, 1988, Japanese telecommunications company

1246:

ISDN is a core technology in the telephone industry. A

1072:

is a serial interface between a computing device and a

513:) is a set of communication standards for simultaneous 2509:"Arcor will ab Sommer Fernsehen per Internet anbieten" 2355:"IPDTL, Source-Connect vs Skype for voice over talent" 2324:. University of Manitoba, Winnipeg, Manitoba, Canada: 2057: 2055: 2011: 2009: 1996: 1994: 1992: 1990: 1988: 1986: 1973: 1971: 1969: 2773:(5 ed.). McGraw-Hill Professional. p. 770. 2113: 2111: 2109: 2255:

Aaron, R; Wyndrum, R (March 1986). "Future trends".

1796:

PBXs use ISDN-PRI circuits. These are connected via

1168:

Even though many network professionals use the term

2659:(in Japanese). JP. November 2, 2010. Archived from 2067: 2052: 2006: 1983: 1966: 1656:Since 2000, NTT's ISDN offering have been known as 1055:is a two-wire interface between the exchange and a 774:This work in the early 1990s eventually led to the 754:achieve 2.048 Mbit/s. By the mid-1990s, these 2540: 2106: 1293:for the user. Another usage was the deployment of 692:sought to liberalize and regulate ISDN across the 2801:Bodin, Madeline; Dawson, Keith (3 January 2002). 2326:Institute of Electrical and Electronics Engineers 1281:In common use, ISDN is often limited to usage to 853:are used for data (which may include voice), and 4456: 1940:IEEE Journal on Selected Areas in Communications 2193: 2027: 1266:to indicate on-hook or off-hook conditions and 1002:In North America, the NT1 device is considered 669:and the US center for development moved to the 610:(AMI), which reached only a few percent of the 2576:"e-Seva: Enabling Bill Payment Without Queues" 2478:"ISDN Product Cease Sale and longer-term exit" 1567:Network Termination for ISDN Basic rate Access 991: – defines the point between the NT2 and 3378: 3121: 1854:Common ISDN Application Programming Interface 1324:One of ISDNs successful use-cases was in the 1262:. Normally, a PBX is connected via a T1 with 1078:, which is the digital equivalent of a modem. 878:Broadband Integrated Services Digital Network 528:and was formally standardized in 1988 in the 479: 2470: 2434: 2254: 2167: 2141: 1038:) and one 16 kbit/s signaling channel ( 4393:Global telecommunications regulation bodies 2800: 2085: 1937: 1804:(DID) trunks. PRI is capable of delivering 1727: 1430: 614:but was appropriate for 1960s electronics. 4429: 3385: 3371: 3128: 3114: 2230:(3 ed.). Wiley Interscience. p. 1820:actor or host is in one studio conducting 1285:and related protocols, which are a set of 841:In ISDN, there are two types of channels, 536:(DSL) systems of much higher performance. 486: 472: 2739:"ISDN: A Solution in Search of a Problem" 2506: 1187:Each one of these channels is known as a 1107: 1022:The entry level interface to ISDN is the 2908: 2770:The Irwin Handbook of Telecommunications 1548: 1013: 524:. Work on the standard began in 1980 at 497: 2686:"Our history in Norway - Telenor Group" 2529:Arcor setzt im Endkundenbereich auf NGN 2381:"BRI ISDN Backup With Backup Interface" 2221: 1112:The other ISDN access available is the 1009: 938:to refer to certain points between the 622:using analog systems. Digitizing this " 14: 4475:Computer-related introductions in 1988 4457: 3392: 2979: 2767:Green, James Harry (26 October 2005). 2073: 2061: 2015: 2000: 1977: 761: 3366: 3109: 2766: 2352: 2285: 1380: 1319: 1241: 671:American National Standards Institute 4439: 2543:"Deutsche Telekom - 100% IP by 2018" 2541:Niek Jan van Damme (16 March 2014). 901:bipolar with eight-zero substitution 681:standard proposed by Peter Adams of 590:Since its introduction in 1881, the 4465:Integrated Services Digital Network 3135: 2745:(article), September–October 1995, 2507:Neuhetzki, Thorsten (24 Jan 2007). 2357:. McCoy Productions. Archived from 2300:from the original on 2 January 2016 2288:"The H.320 Recommendation Overview" 2181:from the original on April 28, 2013 2151:. Southwestern Bell. Archived from 2088:IEEE Transactions on Communications 1913:Dr. rer. nat. Peter Bocker (1988). 1737:highlighting these issues, such as 1630:Life Insurance Corporation of India 922: 698:Council of the European Communities 507:Integrated Services Digital Network 52:Integrated Services Digital Network 24: 18:Integrated Services Digital Network 2872: 2488:from the original on 3 August 2018 2028:Schulte-Braucks, Reinhard (1989). 1743:Innovations Subscribers Don't Need 1140:Non-Facility Associated Signalling 688:From an economic perspective, the 633: 27:Set of digital telephony standards 25: 4516: 2973: 2947:Internet Access service offerings 1714:Home Highway and Business Highway 1699: 1314:public switched telephone network 1175: 1163:public switched telephone network 836: 522:public switched telephone network 39:SDN (Software-defined networking) 4438: 4428: 4419: 4418: 4407: 4028:Free-space optical communication 3043: 2519:from the original on 2 June 2016 2451:. March 15, 2015. Archived from 2442:"ISDN ON BUSINESSLINE® COMPLETE" 2125:. March 28, 2013. Archived from 1785:predictable quality and where a 732:took over telephone lines while 612:theoretical capacity of the line 585: 3075:from the original on 2010-06-11 3054:from the original on 2010-08-18 3033:from the original on 2012-08-27 3012:from the original on 2021-05-01 2937: 2926:from the original on 2021-06-06 2866: 2856:from the original on 2011-05-27 2840: 2828: 2794: 2760: 2749:from the original on 2011-07-18 2731: 2707: 2696:from the original on 2022-12-03 2678: 2640: 2629:from the original on 2012-10-17 2608: 2567: 2555:from the original on 2021-12-11 2534: 2500: 2402: 2391:from the original on 2020-03-04 2373: 2346: 2328:. May 22–23, 1997. p. 30. 2312: 2279: 2248: 2215: 2175:"What Is Basic Rate Interface?" 2079: 1422: 1063:in non-North American networks. 1018:A decommissioned BT ISDN 2e box 700:adopted Council Recommendation 2286:Davis, Andrew (13 June 1997). 2021: 1931: 1917:. Springer Berlin Heidelberg. 1906: 1886: 1733:long been known by derogatory 1224: 1194:Most B channels can carry a 64 13: 1: 3064: 2573: 1899: 1116:(PRI), which is carried over 4414:Telecommunication portal 4195:Telecommunications equipment 2986:IEEE Communications Magazine 2950:, CenturyTel, archived from 2807:. Focal Press. p. 227. 2257:IEEE Communications Magazine 1617:Bharat Sanchar Nigam Limited 1512: 1146:, which is sometimes called 942:and the end-user equipment. 7: 4470:Computer network technology 3931:Alexander Stepanovich Popov 2353:McCoy, Jason (2014-02-05). 1842: 1826:plain old telephone service 1806:Calling Line Identification 1004:customer premises equipment 694:European Economic Community 107:Plain old telephone service 80:; 36 years ago 62:; 44 years ago 10: 4521: 3635:Telecommunications history 2265:AT&T Bell Laboratories 1859:Asynchronous Transfer Mode 1837:Northeastern United States 1576:Until 2007 ISDN (BRI) and 1544: 979:Network Termination Type 2 718: 580: 36: 29: 4402: 4344: 4281: 4243:Public Switched Telephone 4203: 4167: 4124: 4065: 4055:telecommunication circuit 4016:Fiber-optic communication 3999: 3761:Francis Blake (telephone) 3708: 3556:Optical telecommunication 3400: 3282: 3264: 3236: 3143: 2998:10.1109/MCOM.2011.5762795 2980:Cioffi, John (May 2011). 2273:10.1109/MCOM.1986.1093028 2222:Bellamy, John C. (2000). 2100:10.1109/TCOM.1979.1094494 1952:10.1109/JSAC.1986.1146333 1874:List of device bandwidths 1758:Broadband Internet access 1686: 1596: 1524: 1363:discrete cosine transform 819:broadband Internet access 797: 667:Bell System was broken up 116: 102: 92: 74: 56: 51: 4154:Orbital angular-momentum 3591:Satellite communications 3430:Communications satellite 3091:, Roblee, archived from 2837:, Lawrence Gasman, p. 91 2743:Computing Japan Magazine 2649:PTSNのマイグレーションについて～概括的展望～ 2648: 2617: 1879: 1728:United States and Canada 1639: 1611: 1431:International deployment 1159:private branch exchanges 1057:network terminating unit 608:alternate mark inversion 37:Not to be confused with 4480:Audio network protocols 4033:Molecular communication 3856:Gardiner Greene Hubbard 3685:Undersea telegraph line 3420:Cable protection system 2589:(1): 74. Archived from 1621:Reliance Communications 1539:point-of-sale terminals 1236: 1205: 1059:, which is usually the 551:to the customers, the " 534:digital subscriber line 140:Internet protocol suite 111:dial-up Internet access 4175:Communication protocol 3961:Charles Sumner Tainter 3776:Walter Houser Brattain 3721:Edwin Howard Armstrong 3529:Information revolution 2852:(report), OECD, 2006, 2422:: BMBF, archived from 1554: 1131:) channels, one data ( 1114:Primary Rate Interface 1108:Primary Rate Interface 1019: 756:Primary Rate Interface 549:copper telephone wires 503: 4485:ITU-T recommendations 4149:Polarization-division 3881:Narinder Singh Kapany 3846:Erna Schneider Hoover 3766:Jagadish Chandra Bose 3746:Alexander Graham Bell 3477:online video platform 2883:: FCC, archived from 2876:Statement of Chairman 2719:www.tmc-telecom.co.uk 2484:. 21 September 2016. 1802:direct inward dialing 1739:It Still Does Nothing 1669:cable Internet access 1552: 1089:Network termination 1 1017: 993:network termination 1 501: 32:ISDN (disambiguation) 3991:Vladimir K. Zworykin 3951:Almon Brown Strowger 3921:Charles Grafton Page 3576:Prepaid mobile phone 3504:Electrical telegraph 2982:"Lighting up copper" 2849:Broadband Statistics 2715:"The Big Switch Off" 2409:"ISDN-Verbreitung", 1264:robbed bit signaling 1024:Basic Rate Interface 1010:Basic Rate Interface 971:terminal equipment 1 951:terminal equipment 2 562:Basic Rate Interface 30:For other uses, see 3941:Johann Philipp Reis 3700:Wireless revolution 3662:The Telephone Cases 3519:Hydraulic telegraph 3283:Long range wireless 2129:on February 3, 2020 1766:ADSL loop extenders 1751:I Smell Dollars Now 1287:signaling protocols 931:are defined in the 845:(for "bearer") and 827:telephone switching 803:Integrated services 762:Replacement by ADSL 734:local area networks 724:different regions. 690:European Commission 48: 4505:Wide area networks 4139:Frequency-division 4116:Telephone exchange 3986:Charles Wheatstone 3916:Jun-ichi Nishizawa 3891:Innocenzo Manzetti 3826:Reginald Fessenden 3561:Optical telegraphy 3394:Telecommunications 2035:Fordham Int'l L.J. 1747:I Still Don't kNow 1555: 1401:outside broadcasts 1381:Broadcast industry 1320:Video conferencing 1242:Telephone industry 1020: 821:and entertainment 707:2022-10-18 at the 504: 46: 4452: 4451: 4190:Store and forward 4185:Data transmission 4099:Network switching 4050:Transmission line 3896:Guglielmo Marconi 3861:Internet pioneers 3726:Mohamed M. Atalla 3695:Whistled language 3360: 3359: 2873:Martin, Kevin J, 2814:978-1-57820-095-5 2780:978-0-07-145222-9 2666:on April 21, 2012 2574:T, Radhakrishna. 2241:978-0-471-34571-8 2226:Digital Telephony 2201:"ISDN\SwitchType" 2155:on April 15, 2013 1924:978-3-662-08036-8 1810:recording studios 1782:videoconferencing 1673:fiber to the home 1571:terminal adapters 1248:telephone network 1061:demarcation point 977:), or a TA and a 882:network backbones 654:echo cancellation 597:crossbar switches 496: 495: 147:Application layer 134: 133: 16:(Redirected from 4512: 4442: 4441: 4432: 4431: 4422: 4421: 4412: 4411: 4410: 4283:Notable networks 4273:Wireless network 4213:Cellular network 4205:Types of network 4180:Computer network 4067:Network topology 3981:Thomas A. Watson 3836:Oliver Heaviside 3821:Philo Farnsworth 3796:Daniel Davis Jr. 3771:Charles Bourseul 3731:John Logie Baird 3440:Data compression 3435:Computer network 3387: 3380: 3373: 3364: 3363: 3130: 3123: 3116: 3107: 3106: 3102: 3101: 3100: 3082: 3081: 3080: 3061: 3060: 3059: 3040: 3039: 3038: 3020: 3018: 3017: 2967: 2965: 2960: 2959: 2941: 2935: 2933: 2932: 2931: 2912: 2906: 2904: 2903: 2902: 2896: 2870: 2864: 2863: 2862: 2861: 2844: 2838: 2832: 2826: 2825: 2823: 2821: 2798: 2792: 2791: 2789: 2787: 2764: 2758: 2756: 2755: 2754: 2735: 2729: 2728: 2726: 2725: 2711: 2705: 2704: 2702: 2701: 2692:(in Norwegian). 2682: 2676: 2675: 2673: 2671: 2665: 2654: 2644: 2638: 2637: 2635: 2634: 2612: 2606: 2605: 2603: 2601: 2596:on April 4, 2015 2595: 2580: 2571: 2565: 2564: 2562: 2560: 2538: 2532: 2531: 2526: 2524: 2504: 2498: 2497: 2495: 2493: 2474: 2468: 2467: 2465: 2463: 2458:on 3 August 2018 2457: 2446: 2438: 2432: 2430: 2428: 2417: 2406: 2400: 2399: 2397: 2396: 2377: 2371: 2370: 2368: 2366: 2350: 2344: 2343: 2316: 2310: 2309: 2307: 2305: 2283: 2277: 2276: 2252: 2246: 2245: 2229: 2219: 2213: 2212: 2210: 2208: 2197: 2191: 2190: 2188: 2186: 2171: 2165: 2164: 2162: 2160: 2145: 2139: 2138: 2136: 2134: 2115: 2104: 2103: 2083: 2077: 2071: 2065: 2059: 2050: 2049: 2047: 2046: 2025: 2019: 2013: 2004: 1998: 1981: 1975: 1964: 1963: 1935: 1929: 1928: 1910: 1893: 1890: 1792:Most modern non- 1563:Deutsche Telekom 1405:broadcast studio 1291:calling features 1197: 1152:Digital Signal 3 1075:terminal adapter 960:terminal adapter 929:reference points 923:Reference points 730:Meridian Norstar 648:voice channels. 488: 481: 474: 136: 135: 88: 86: 81: 70: 68: 63: 49: 45: 21: 4520: 4519: 4515: 4514: 4513: 4511: 4510: 4509: 4455: 4454: 4453: 4448: 4408: 4406: 4398: 4340: 4277: 4199: 4163: 4120: 4069: 4061: 4002: 3995: 3901:Robert Metcalfe 3756:Tim Berners-Lee 3704: 3524:Information Age 3396: 3391: 3361: 3356: 3278: 3260: 3232: 3139: 3137:Internet access 3134: 3098: 3096: 3085: 3078: 3076: 3057: 3055: 3036: 3034: 3023: 3015: 3013: 2976: 2971: 2970: 2957: 2955: 2943: 2942: 2938: 2929: 2927: 2914: 2913: 2909: 2900: 2898: 2887: 2871: 2867: 2859: 2857: 2846: 2845: 2841: 2833: 2829: 2819: 2817: 2815: 2799: 2795: 2785: 2783: 2781: 2765: 2761: 2752: 2750: 2737: 2736: 2732: 2723: 2721: 2713: 2712: 2708: 2699: 2697: 2690:www.telenor.com 2684: 2683: 2679: 2669: 2667: 2663: 2652: 2650: 2646: 2645: 2641: 2632: 2630: 2625:(in Japanese). 2619: 2614: 2613: 2609: 2599: 2597: 2593: 2578: 2572: 2568: 2558: 2556: 2539: 2535: 2522: 2520: 2505: 2501: 2491: 2489: 2476: 2475: 2471: 2461: 2459: 2455: 2444: 2440: 2439: 2435: 2426: 2415: 2408: 2407: 2403: 2394: 2392: 2379: 2378: 2374: 2364: 2362: 2351: 2347: 2336: 2318: 2317: 2313: 2303: 2301: 2284: 2280: 2253: 2249: 2242: 2220: 2216: 2206: 2204: 2199: 2198: 2194: 2184: 2182: 2173: 2172: 2168: 2158: 2156: 2149:"What is ISDN?" 2147: 2146: 2142: 2132: 2130: 2117: 2116: 2107: 2084: 2080: 2072: 2068: 2060: 2053: 2044: 2042: 2026: 2022: 2014: 2007: 1999: 1984: 1976: 1967: 1936: 1932: 1925: 1911: 1907: 1902: 1897: 1896: 1891: 1887: 1882: 1845: 1730: 1710:British Telecom 1702: 1689: 1642: 1614: 1599: 1547: 1527: 1515: 1433: 1425: 1383: 1326:videoconference 1322: 1295:videoconference 1244: 1239: 1227: 1208: 1195: 1178: 1110: 1032:bearer channels 1012: 925: 839: 800: 764: 721: 709:Wayback Machine 683:British Telecom 636: 634:Standardization 588: 583: 570:videoconference 492: 312:Transport layer 84: 82: 79: 75:First published 66: 64: 61: 42: 35: 28: 23: 22: 15: 12: 11: 5: 4518: 4508: 4507: 4502: 4500:Videotelephony 4497: 4492: 4490:Network access 4487: 4482: 4477: 4472: 4467: 4450: 4449: 4447: 4446: 4436: 4426: 4416: 4403: 4400: 4399: 4397: 4396: 4389: 4384: 4379: 4374: 4369: 4368: 4367: 4362: 4354: 4348: 4346: 4342: 4341: 4339: 4338: 4333: 4328: 4323: 4318: 4313: 4308: 4303: 4298: 4293: 4287: 4285: 4279: 4278: 4276: 4275: 4270: 4265: 4260: 4255: 4250: 4245: 4240: 4235: 4230: 4225: 4220: 4215: 4209: 4207: 4201: 4200: 4198: 4197: 4192: 4187: 4182: 4177: 4171: 4169: 4165: 4164: 4162: 4161: 4156: 4151: 4146: 4141: 4136: 4134:Space-division 4130: 4128: 4122: 4121: 4119: 4118: 4113: 4112: 4111: 4106: 4096: 4095: 4094: 4084: 4079: 4073: 4071: 4063: 4062: 4060: 4059: 4058: 4057: 4047: 4046: 4045: 4035: 4030: 4025: 4024: 4023: 4013: 4007: 4005: 3997: 3996: 3994: 3993: 3988: 3983: 3978: 3973: 3971:Camille Tissot 3968: 3963: 3958: 3953: 3948: 3946:Claude Shannon 3943: 3938: 3936:Tivadar Puskás 3933: 3928: 3923: 3918: 3913: 3908: 3906:Antonio Meucci 3903: 3898: 3893: 3888: 3883: 3878: 3876:Charles K. Kao 3873: 3868: 3863: 3858: 3853: 3851:Harold Hopkins 3848: 3843: 3838: 3833: 3828: 3823: 3818: 3813: 3808: 3803: 3798: 3793: 3788: 3783: 3778: 3773: 3768: 3763: 3758: 3753: 3751:Emile Berliner 3748: 3743: 3738: 3733: 3728: 3723: 3718: 3712: 3710: 3706: 3705: 3703: 3702: 3697: 3692: 3690:Videotelephony 3687: 3682: 3681: 3680: 3675: 3665: 3658: 3653: 3647: 3642: 3637: 3632: 3627: 3626: 3625: 3620: 3615: 3605: 3604: 3603: 3593: 3588: 3586:Radiotelephone 3583: 3578: 3573: 3568: 3563: 3558: 3553: 3552: 3551: 3541: 3536: 3531: 3526: 3521: 3516: 3511: 3506: 3501: 3496: 3491: 3490: 3489: 3484: 3479: 3474: 3472:Internet video 3464: 3463: 3462: 3457: 3452: 3447: 3437: 3432: 3427: 3422: 3417: 3412: 3406: 3404: 3398: 3397: 3390: 3389: 3382: 3375: 3367: 3358: 3357: 3355: 3354: 3353: 3352: 3342: 3337: 3332: 3327: 3322: 3317: 3312: 3307: 3302: 3297: 3292: 3286: 3284: 3280: 3279: 3277: 3276: 3270: 3268: 3262: 3261: 3259: 3258: 3253: 3248: 3242: 3240: 3234: 3233: 3231: 3230: 3229: 3228: 3218: 3213: 3208: 3203: 3198: 3193: 3188: 3183: 3178: 3173: 3168: 3163: 3158: 3153: 3147: 3145: 3141: 3140: 3133: 3132: 3125: 3118: 3110: 3104: 3103: 3083: 3062: 3041: 3021: 2975: 2974:External links 2972: 2969: 2968: 2944:"Disclaimer", 2936: 2922:, 2008-03-19, 2907: 2865: 2839: 2827: 2813: 2793: 2779: 2759: 2730: 2706: 2677: 2639: 2607: 2583:Real CIO World 2566: 2533: 2499: 2469: 2433: 2401: 2372: 2345: 2334: 2311: 2278: 2247: 2240: 2214: 2192: 2166: 2140: 2105: 2078: 2066: 2051: 2020: 2005: 1982: 1965: 1930: 1923: 1904: 1903: 1901: 1898: 1895: 1894: 1884: 1883: 1881: 1878: 1877: 1876: 1871: 1866: 1861: 1856: 1851: 1849:ISDN User Part 1844: 1841: 1814:radio programs 1729: 1726: 1706:United Kingdom 1701: 1700:United Kingdom 1698: 1688: 1685: 1641: 1638: 1613: 1610: 1598: 1595: 1546: 1543: 1535:business voice 1526: 1523: 1514: 1511: 1510: 1509: 1503: 1497: 1491: 1485: 1479: 1473: 1470:United Kingdom 1467: 1461: 1455: 1449: 1443: 1432: 1429: 1424: 1421: 1403:into the main 1382: 1379: 1321: 1318: 1243: 1240: 1238: 1235: 1226: 1223: 1207: 1204: 1177: 1176:Bearer channel 1174: 1109: 1106: 1102: 1101: 1092: 1079: 1064: 1011: 1008: 997: 996: 995:(NT1) devices. 986: 964: 924: 921: 849:(for "data"). 838: 837:Configurations 835: 799: 796: 763: 760: 720: 717: 635: 632: 587: 584: 582: 579: 502:ISDN telephone 494: 493: 491: 490: 483: 476: 468: 465: 464: 463: 462: 455: 450: 445: 440: 432: 431: 425: 424: 423: 422: 415: 410: 405: 400: 395: 385: 384: 383: 378: 365: 364: 362:Internet layer 358: 357: 356: 355: 348: 343: 338: 333: 328: 323: 315: 314: 308: 307: 306: 305: 298: 293: 288: 283: 278: 273: 268: 263: 258: 253: 248: 243: 238: 233: 228: 223: 218: 213: 208: 203: 198: 193: 188: 178: 173: 168: 158: 150: 149: 143: 142: 132: 131: 118: 114: 113: 104: 100: 99: 94: 90: 89: 76: 72: 71: 58: 54: 53: 26: 9: 6: 4: 3: 2: 4517: 4506: 4503: 4501: 4498: 4496: 4493: 4491: 4488: 4486: 4483: 4481: 4478: 4476: 4473: 4471: 4468: 4466: 4463: 4462: 4460: 4445: 4437: 4435: 4427: 4425: 4417: 4415: 4405: 4404: 4401: 4394: 4390: 4388: 4385: 4383: 4380: 4378: 4375: 4373: 4370: 4366: 4363: 4361: 4358: 4357: 4355: 4353: 4350: 4349: 4347: 4343: 4337: 4334: 4332: 4329: 4327: 4324: 4322: 4319: 4317: 4314: 4312: 4309: 4307: 4304: 4302: 4299: 4297: 4294: 4292: 4289: 4288: 4286: 4284: 4280: 4274: 4271: 4269: 4266: 4264: 4261: 4259: 4256: 4254: 4251: 4249: 4246: 4244: 4241: 4239: 4236: 4234: 4231: 4229: 4226: 4224: 4221: 4219: 4216: 4214: 4211: 4210: 4208: 4206: 4202: 4196: 4193: 4191: 4188: 4186: 4183: 4181: 4178: 4176: 4173: 4172: 4170: 4166: 4160: 4159:Code-division 4157: 4155: 4152: 4150: 4147: 4145: 4144:Time-division 4142: 4140: 4137: 4135: 4132: 4131: 4129: 4127: 4123: 4117: 4114: 4110: 4107: 4105: 4102: 4101: 4100: 4097: 4093: 4090: 4089: 4088: 4085: 4083: 4080: 4078: 4075: 4074: 4072: 4070:and switching 4068: 4064: 4056: 4053: 4052: 4051: 4048: 4044: 4041: 4040: 4039: 4036: 4034: 4031: 4029: 4026: 4022: 4021:optical fiber 4019: 4018: 4017: 4014: 4012: 4011:Coaxial cable 4009: 4008: 4006: 4004: 3998: 3992: 3989: 3987: 3984: 3982: 3979: 3977: 3974: 3972: 3969: 3967: 3964: 3962: 3959: 3957: 3954: 3952: 3949: 3947: 3944: 3942: 3939: 3937: 3934: 3932: 3929: 3927: 3926:Radia Perlman 3924: 3922: 3919: 3917: 3914: 3912: 3909: 3907: 3904: 3902: 3899: 3897: 3894: 3892: 3889: 3887: 3884: 3882: 3879: 3877: 3874: 3872: 3869: 3867: 3864: 3862: 3859: 3857: 3854: 3852: 3849: 3847: 3844: 3842: 3839: 3837: 3834: 3832: 3829: 3827: 3824: 3822: 3819: 3817: 3816:Lee de Forest 3814: 3812: 3811:Thomas Edison 3809: 3807: 3804: 3802: 3801:Donald Davies 3799: 3797: 3794: 3792: 3789: 3787: 3786:Claude Chappe 3784: 3782: 3779: 3777: 3774: 3772: 3769: 3767: 3764: 3762: 3759: 3757: 3754: 3752: 3749: 3747: 3744: 3742: 3739: 3737: 3734: 3732: 3729: 3727: 3724: 3722: 3719: 3717: 3714: 3713: 3711: 3707: 3701: 3698: 3696: 3693: 3691: 3688: 3686: 3683: 3679: 3676: 3674: 3671: 3670: 3669: 3666: 3664: 3663: 3659: 3657: 3654: 3651: 3648: 3646: 3643: 3641: 3638: 3636: 3633: 3631: 3630:Smoke signals 3628: 3624: 3621: 3619: 3616: 3614: 3611: 3610: 3609: 3608:Semiconductor 3606: 3602: 3599: 3598: 3597: 3594: 3592: 3589: 3587: 3584: 3582: 3579: 3577: 3574: 3572: 3569: 3567: 3564: 3562: 3559: 3557: 3554: 3550: 3547: 3546: 3545: 3542: 3540: 3537: 3535: 3532: 3530: 3527: 3525: 3522: 3520: 3517: 3515: 3512: 3510: 3507: 3505: 3502: 3500: 3497: 3495: 3492: 3488: 3485: 3483: 3480: 3478: 3475: 3473: 3470: 3469: 3468: 3467:Digital media 3465: 3461: 3458: 3456: 3453: 3451: 3448: 3446: 3443: 3442: 3441: 3438: 3436: 3433: 3431: 3428: 3426: 3423: 3421: 3418: 3416: 3413: 3411: 3408: 3407: 3405: 3403: 3399: 3395: 3388: 3383: 3381: 3376: 3374: 3369: 3368: 3365: 3351: 3348: 3347: 3346: 3343: 3341: 3338: 3336: 3333: 3331: 3328: 3326: 3323: 3321: 3318: 3316: 3313: 3311: 3308: 3306: 3303: 3301: 3298: 3296: 3293: 3291: 3288: 3287: 3285: 3281: 3275: 3272: 3271: 3269: 3267: 3263: 3257: 3254: 3252: 3249: 3247: 3244: 3243: 3241: 3239: 3235: 3227: 3224: 3223: 3222: 3219: 3217: 3214: 3212: 3209: 3207: 3204: 3202: 3199: 3197: 3194: 3192: 3189: 3187: 3184: 3182: 3179: 3177: 3174: 3172: 3169: 3167: 3164: 3162: 3159: 3157: 3154: 3152: 3149: 3148: 3146: 3142: 3138: 3131: 3126: 3124: 3119: 3117: 3112: 3111: 3108: 3095:on 2010-03-07 3094: 3090: 3089: 3084: 3074: 3070: 3069: 3063: 3053: 3049: 3048: 3042: 3032: 3029:(list), ITU, 3028: 3027: 3022: 3011: 3007: 3003: 2999: 2995: 2991: 2987: 2983: 2978: 2977: 2964: 2954:on 2008-12-25 2953: 2949: 2948: 2940: 2925: 2921: 2917: 2911: 2897:on 2011-10-17 2894: 2891: 2886: 2882: 2878: 2877: 2869: 2855: 2851: 2850: 2843: 2836: 2831: 2816: 2810: 2806: 2805: 2797: 2782: 2776: 2772: 2771: 2763: 2748: 2744: 2740: 2734: 2720: 2716: 2710: 2695: 2691: 2687: 2681: 2662: 2658: 2651: 2643: 2628: 2624: 2620: 2618:NTT東日本 - 北浜ビル 2611: 2592: 2588: 2584: 2577: 2570: 2554: 2550: 2549: 2544: 2537: 2530: 2518: 2514: 2510: 2503: 2487: 2483: 2479: 2473: 2454: 2450: 2443: 2437: 2429:on 2008-10-02 2425: 2421: 2414: 2413: 2405: 2390: 2386: 2382: 2376: 2361:on 2015-02-28 2360: 2356: 2349: 2342: 2337: 2335:9780780341470 2331: 2327: 2323: 2322: 2315: 2299: 2295: 2294: 2289: 2282: 2274: 2270: 2266: 2262: 2258: 2251: 2243: 2237: 2233: 2228: 2227: 2218: 2202: 2196: 2180: 2176: 2170: 2154: 2150: 2144: 2128: 2124: 2120: 2114: 2112: 2110: 2101: 2097: 2093: 2089: 2082: 2076:, p. 38. 2075: 2070: 2064:, p. 34. 2063: 2058: 2056: 2040: 2037: 2036: 2031: 2024: 2018:, p. 32. 2017: 2012: 2010: 2003:, p. 31. 2002: 1997: 1995: 1993: 1991: 1989: 1987: 1980:, p. 30. 1979: 1974: 1972: 1970: 1961: 1957: 1953: 1949: 1946:(3): 320–25. 1945: 1941: 1934: 1926: 1920: 1916: 1909: 1905: 1889: 1885: 1875: 1872: 1870: 1867: 1865: 1862: 1860: 1857: 1855: 1852: 1850: 1847: 1846: 1840: 1838: 1834: 1829: 1827: 1823: 1819: 1815: 1811: 1807: 1803: 1799: 1795: 1790: 1788: 1783: 1778: 1775: 1771: 1767: 1763: 1759: 1754: 1752: 1748: 1744: 1740: 1736: 1725: 1722: 1719: 1715: 1711: 1707: 1697: 1694: 1684: 1682: 1678: 1674: 1670: 1666: 1661: 1659: 1654: 1650: 1647: 1637: 1635: 1631: 1626: 1625:Bharti Airtel 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990: 987: 984: 980: 976: 972: 968: 965: 962: 961: 956: 952: 948: 945: 944: 943: 941: 937: 934: 930: 920: 918: 914: 909: 907: 902: 897: 894: 889: 887: 883: 879: 875: 871: 867: 863: 858: 856: 852: 848: 844: 834: 832: 828: 824: 820: 816: 812: 808: 804: 795: 791: 789: 785: 781: 777: 772: 769: 759: 757: 752: 751:standards war 746: 742: 739: 735: 731: 725: 716: 714: 710: 706: 703: 699: 695: 691: 686: 684: 680: 676: 672: 668: 662: 659: 655: 649: 646: 641: 631: 629: 625: 621: 615: 613: 609: 605: 600: 598: 593: 586:Digital lines 578: 575: 571: 565: 563: 558: 554: 550: 546: 542: 537: 535: 531: 527: 523: 519: 516: 512: 508: 500: 489: 484: 482: 477: 475: 470: 469: 467: 466: 461: 460: 456: 454: 451: 449: 446: 444: 441: 439: 436: 435: 434: 433: 430: 427: 426: 421: 420: 416: 414: 411: 409: 406: 404: 401: 399: 396: 393: 389: 386: 382: 379: 377: 374: 373: 372: 369: 368: 367: 366: 363: 360: 359: 354: 353: 349: 347: 344: 342: 339: 337: 334: 332: 329: 327: 324: 322: 319: 318: 317: 316: 313: 310: 309: 304: 303: 299: 297: 294: 292: 289: 287: 284: 282: 279: 277: 274: 272: 269: 267: 264: 262: 259: 257: 254: 252: 249: 247: 244: 242: 239: 237: 234: 232: 229: 227: 224: 222: 219: 217: 214: 212: 209: 207: 204: 202: 199: 197: 194: 192: 189: 186: 182: 179: 177: 174: 172: 169: 166: 162: 159: 157: 154: 153: 152: 151: 148: 145: 144: 141: 138: 137: 130: 126: 122: 119: 115: 112: 108: 105: 101: 98: 95: 91: 77: 73: 59: 55: 50: 44: 40: 33: 19: 4126:Multiplexing 4001:Transmission 3966:Nikola Tesla 3956:Henry Sutton 3911:Samuel Morse 3841:Robert Hooke 3806:Amos Dolbear 3741:John Bardeen 3660: 3640:Telautograph 3544:Mobile phone 3499:Edholm's law 3482:social media 3415:Broadcasting 3266:Wireless LAN 3256:Wireless USB 3238:Wireless PAN 3097:, retrieved 3093:the original 3087: 3077:, retrieved 3067: 3056:, retrieved 3046: 3035:, retrieved 3025: 3014:. Retrieved 2992:(5): 30–43. 2989: 2985: 2962: 2956:, retrieved 2952:the original 2946: 2939: 2928:, retrieved 2919: 2910: 2899:, retrieved 2885:the original 2875: 2868: 2858:, retrieved 2848: 2842: 2830: 2818:. Retrieved 2803: 2796: 2784:. Retrieved 2769: 2762: 2751:, retrieved 2742: 2733: 2722:. Retrieved 2718: 2709: 2698:. Retrieved 2689: 2680: 2668:. Retrieved 2661:the original 2656: 2642: 2631:. Retrieved 2622: 2610: 2598:. Retrieved 2591:the original 2586: 2582: 2569: 2557:. Retrieved 2546: 2536: 2528: 2521:. Retrieved 2512: 2502: 2490:. Retrieved 2481: 2472: 2460:. Retrieved 2453:the original 2448: 2436: 2424:the original 2411: 2404: 2393:. Retrieved 2384: 2375: 2363:. Retrieved 2359:the original 2348: 2339: 2320: 2314: 2302:. Retrieved 2291: 2281: 2260: 2256: 2250: 2225: 2217: 2205:. Retrieved 2195: 2183:. Retrieved 2169: 2157:. Retrieved 2153:the original 2143: 2131:. Retrieved 2127:the original 2122: 2091: 2087: 2081: 2069: 2043:. 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Microsoft 2094:(7): 1071. 2074:Cioffi 2011 2062:Cioffi 2011 2016:Cioffi 2011 2001:Cioffi 2011 1978:Cioffi 2011 1822:remote work 1458:Switzerland 1415:ACCESS and 1397:BBC Radio 3 1231:Frame Relay 1229:In theory, 1225:Frame Relay 1097:R interface 1084:S interface 1069:T interface 1052:U interface 1040:'D' channel 906:multiplexed 815:single line 658:John Cioffi 628:fiber optic 103:Predecessor 4459:Categories 4372:Antarctica 4331:Toasternet 4253:Television 3736:Paul Baran 3668:Television 3652:(teletype) 3645:Telegraphy 3623:transistor 3601:Phryctoria 3571:Photophone 3549:Smartphone 3539:Mass media 3330:Muni Wi-Fi 3221:Power-line 3099:2007-08-02 3079:2004-11-04 3065:B, Ralph, 3058:2003-08-14 3037:2008-08-19 3016:2020-09-25 2958:2009-06-07 2930:2017-09-01 2901:2012-12-10 2860:2012-12-10 2753:2009-06-05 2724:2021-01-29 2700:2023-11-24 2633:2012-06-13 2623:Denwakyoku 2395:2020-03-04 2304:7 November 2045:2022-10-18 1900:References 1818:voice-over 1774:CenturyTel 1735:backronyms 1681:IP network 1154:(DS3/T3). 855:D channels 851:B channels 823:television 702:86/659/EEC 620:end office 429:Link layer 4495:Telephony 4356:Americas 4345:Locations 4316:Internet2 4077:Bandwidth 3781:Vint Cerf 3678:streaming 3656:Telephone 3596:Semaphore 3487:streaming 3335:Satellite 3246:Bluetooth 3226:Broadband 3201:IEEE 1901 2267:: 38–43. 1960:0733-8716 1831:In 2013, 1816:, when a 1812:and some 1513:Australia 1144:D channel 1122:E-carrier 1118:T-carrier 957:), and a 927:A set of 813:, over a 768:crosstalk 675:Ameritech 640:Bell Labs 624:last mile 604:Bell Labs 553:last mile 526:Bell Labs 121:Broadband 117:Successor 4424:Category 4311:Internet 4301:CYCLADES 4218:Ethernet 4168:Concepts 4092:terminal 4043:wireless 3866:Bob Kahn 3709:Pioneers 3534:Internet 3425:Cable TV 3340:UMTS-TDD 3191:HomePlug 3171:Ethernet 3073:archived 3052:archived 3031:archived 3010:Archived 2924:archived 2920:Engadget 2854:archived 2747:archived 2694:Archived 2670:June 20, 2657:NTT East 2627:Archived 2553:Archived 2517:Archived 2492:3 August 2486:Archived 2462:3 August 2389:Archived 2365:16 March 2298:Archived 2293:EE Times 2207:April 6, 2185:April 6, 2179:Archived 2159:April 6, 2133:April 6, 2041:(2): 234 1843:See also 1798:T1 lines 1772:such as 1369:such as 1345:such as 1165:(PSTN). 985:) device 936:standard 738:Ethernet 705:Archived 123:such as 4444:Commons 4434:Outline 4387:Oceania 4306:FidoNet 4291:ARPANET 4104:circuit 3673:digital 3402:History 3196:HomePNA 3156:Dial-up 3006:8661205 2600:4 April 2548:YouTube 2482:Telstra 2449:Telstra 2123:Talkers 1833:Verizon 1704:In the 1693:Telenor 1679:to the 1559:Germany 1545:Germany 1518:Telstra 1476:Finland 1452:Germany 1446:Denmark 1361:), and 1161:to the 788:Alcatel 780:Alcatel 719:Rollout 581:History 515:digital 459:more... 443:Tunnels 419:more... 352:more... 302:more... 291:TLS/SSL 246:ONC/RPC 183: ( 83: ( 65: ( 4382:Europe 4352:Africa 4336:Usenet 4296:BITNET 4233:Mobile 4109:packet 3618:MOSFET 3613:device 3410:Beacon 3315:iBurst 3186:Nessum 3161:DOCSIS 3044:Fine, 3004: 2820:12 May 2811: 2786:12 May 2777: 2412:Studie 2341:lines. 2332: 2238: 1958: 1921: 1864:B-ISDN 1745:, and 1687:Norway 1671:, and 1658:FLET's 1636:ATMs. 1632:, and 1606:Greece 1597:Greece 1530:Orange 1525:France 1494:France 1482:Sweden 1440:Norway 1413:Comrex 1365:(DCT) 1353:) and 1196: 1091:(NT1). 1028:kbit/s 899:Using 893:bonded 866:Mbit/s 862:kbit/s 809:, and 798:Design 696:. The 645:modems 557:modems 286:Telnet 185:HTTP/3 4365:South 4360:North 4321:JANET 4258:Telex 4248:Radio 4087:Nodes 4082:Links 4003:media 3581:Radio 3566:Pager 3494:Drums 3460:video 3455:image 3445:audio 3350:WiBro 3345:WiMAX 3290:5G NR 3274:Wi-Fi 3251:Li-Fi 3151:Cable 3144:Wired 3002:S2CID 2664:(PDF) 2653:(PDF) 2594:(PDF) 2579:(PDF) 2559:7 May 2523:7 May 2456:(PDF) 2445:(PDF) 2427:(PDF) 2416:(PDF) 2385:Cisco 2263:(3). 1880:Notes 1770:CLECs 1640:Japan 1612:India 1500:Spain 1488:Italy 1464:Japan 1417:ipDTL 1392:G.722 1387:codec 1375:H.263 1371:H.261 1355:G.728 1347:G.711 1331:H.320 1299:H.320 1283:Q.931 1182:G.711 940:telco 807:video 784:DSLAM 736:like 574:H.320 530:CCITT 413:IPsec 191:HTTPS 109:with 97:ITU-T 4377:Asia 4263:UUCP 4223:ISDN 3325:MMDS 3310:HSPA 3305:GPRS 3300:EVDO 3295:DECT 3211:MoCA 3206:ISDN 3181:G.hn 3176:FTTx 3088:ISDN 3068:ISDN 3047:ISDN 2895:doc) 2893:Word 2822:2012 2809:ISBN 2788:2012 2775:ISBN 2672:2014 2602:2015 2561:2016 2525:2016 2494:2018 2464:2018 2367:2015 2330:ISBN 2306:2019 2236:ISBN 2209:2013 2187:2013 2161:2013 2135:2013 1956:ISSN 1919:ISBN 1869:ETSI 1794:VoIP 1762:ADSL 1677:PSTN 1665:ADSL 1623:and 1587:VoIP 1582:VDSL 1578:ADSL 1537:and 1373:and 1359:CELP 1337:and 1305:and 1272:DTMF 1270:and 1237:Uses 1218:X.25 1211:X.25 1206:X.25 1170:ISDN 1094:The 1081:The 1066:The 1049:The 933:ISDN 917:X.31 913:X.25 829:and 776:ADSL 713:ETSI 679:2B1Q 511:ISDN 408:IGMP 388:ICMP 346:QUIC 341:RSVP 336:SCTP 331:DCCP 296:XMPP 276:SNMP 271:SMTP 256:RTSP 231:OSPF 221:NNTP 216:MQTT 211:MGCP 206:LDAP 196:IMAP 181:HTTP 161:DHCP 129:FTTx 85:1988 78:1988 67:1980 60:1980 47:ISDN 4268:WAN 4238:NGN 4228:LAN 3509:Fax 3450:DCT 3320:LTE 3216:PON 3166:DSL 2994:doi 2269:doi 2232:496 2096:doi 1948:doi 1787:QoS 1718:USB 1646:NTT 1634:SBI 1602:OTE 1557:In 1490:105 1484:135 1478:160 1472:160 1466:240 1460:331 1454:333 1448:339 1442:401 1351:PCM 1260:SS7 1254:or 1200:RBS 1189:DS0 983:NT2 975:TE1 955:TE2 886:ATM 876:). 811:fax 453:MAC 448:PPP 438:ARP 403:ECN 398:NDP 326:UDP 321:TCP 281:SSH 266:SIP 261:RIP 251:RTP 241:PTP 236:POP 226:NTP 201:IRC 176:FTP 171:DNS 156:BGP 127:or 125:DSL 4461:: 3071:, 3008:. 3000:. 2990:49 2988:. 2984:. 2961:, 2918:, 2890:MS 2881:US 2879:, 2741:, 2717:. 2688:. 2655:. 2621:. 2585:. 2581:. 2551:. 2545:. 2527:. 2515:. 2511:. 2480:. 2447:. 2420:DE 2418:, 2387:. 2383:. 2338:. 2296:. 2290:. 2261:24 2259:. 2234:. 2177:. 2121:. 2108:^ 2092:27 2090:. 2054:^ 2039:13 2032:. 2008:^ 1985:^ 1968:^ 1954:. 1942:. 1839:. 1753:. 1741:, 1708:, 1667:, 1619:, 1508:47 1502:58 1496:85 1377:. 1309:. 1276:ms 1268:MF 1256:E1 1252:T1 1191:. 888:. 874:E1 870:T1 545:E1 541:T1 392:v6 381:v6 376:v4 371:IP 165:v6 4395:) 4391:( 3386:e 3379:t 3372:v 3129:e 3122:t 3115:v 3019:. 2996:: 2966:. 2934:. 2905:. 2888:( 2824:. 2790:. 2757:. 2727:. 2703:. 2674:. 2636:. 2604:. 2587:1 2563:. 2496:. 2466:. 2431:. 2398:. 2369:. 2308:. 2275:. 2271:: 2244:. 2211:. 2189:. 2163:. 2137:. 2102:. 2098:: 2048:. 1962:. 1950:: 1944:4 1927:. 1580:/ 1357:( 1349:( 1133:D 1129:B 1034:( 989:T 981:( 973:( 967:S 953:( 947:R 868:( 847:D 843:B 543:/ 509:( 487:e 480:t 473:v 394:) 390:( 187:) 167:) 163:( 87:) 69:) 41:. 34:. 20:)

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