726:) doing so (but with 6P6C instead of 6P4C sockets) slightly later, some time before BS 6312 was rolled out by BT in the UK. Irish, Malaysian and Singaporean phone sockets are normally wired, as per the international standard, with the line carried on the centre pair (pin 3 and 4). However, although rarely connected in practice, Irish phone jacks also contain a ringing capacitor circuit very similar to their UK counterparts. This is carried on pin 5. Or, if wired for two-line service (rare), a second ring wire is carried on pin 2 for line 2, with the outer pair, pins 1 and 6 carrying the second line. This arrangement was introduced for the same reason as the capacitor in BS 6313; to allow backwards compatibility with older GPO style type 3 wire phones that lacked an anti-tinkle circuit, which were common in the 1970s and into the 1980s. Modern Irish jacks also contain screw down lugs to connect extension phone wiring or a hardwired pre 1970s phone. The connection block has an "R" terminal for connecting the ringing wire to the capacitor. Despite the circuitry being available in the jack, UK phones should still be connected with an adapter with its own ringing capacitor, as the "R" wire typically is no longer connected in most homes, unless the wiring was originally used with rotary dial telephones.
965:
series, should eliminate the problem. The RJ11 female port provided on the filter case simply connects the DSL router directly to the phone line (most DSL filters have a socket marked DSL or ADSL that just connects the DSL line pair directly through to the incoming phone line pair via the BT plug, without any filtering or processing of any kind). The ringer wire is unnecessary in unfiltered parts of the wiring and its removal can often improve performance and reliability of the broadband service. This is due to the unbalancing effect that the ringer wire (on long extensions) can have on the matched twisted pair. Thus reducing the signal to noise ratio and also the high frequency response of the subscriber line.
754:
169:
766:
802:
814:
22:
454:
436:
317:
telephone line to be easily disconnected from the internal wiring, provided the wiring of the premises has been correctly carried out. This leaves a single working master telephone connector; if a telephone connected to this connector works while there had been problems with telephones connected to extensions, faults must be due to the customer's wiring in the building. The terminals on the back part were originally large screw terminals, later replaced in all BT NTE5 sockets by
491:
399:
830:
however is the same diameter as 6-wire to allow technicians to retain existing tacking guns and cable clips. Note that the wires in the 6-wire cable are coloured with two colours in a ratio of four to one in length, with the first colour mentioned being the predominant one, e.g. if the indicated colour of the wire is W-B then the wire will be coloured white for 12 mm, then blue for 3 mm and so on. (In other words, it looks like a white wire with blue patches on it.)
473:
418:
3331:
2269:
1595:
837:
778:
849:
874:
72:
362:
790:
235:
3344:
2281:
977:
935:
988:, as it is fitted between the socket and the front panel. This plate is fitted by the consumer inside the NTE 5 and reduces interference carried by the 3rd (bell) wire. The reduced interference allows faster broadband speeds - BT claim a speed improvement of up to 1.5 Mbit/s with a theoretical 4 Mbit/s. By November 2009 BT were calling the I-plate a "BT Broadband Accelerator".
227:
219:
961:. This is a low pass filter in line with the phone outlet. This prevents high frequency data noise from affecting the lower frequency voice bandwidth and it also prevents the low impedance of the connected phone from attenuating or modulating the high speed DSL data Path. Enough bandwidth is retained for voice telephony and the majority is used for high speed data.
292:
V. (long line limit) Line polarity reverses during calls if caller ID is in use. Once in a call the audio and tone levels superimposed on the DC voltage are expressed as dBm in 600 ohms, although the line impedances are permitted to be some way off 600 ohms (as per SIN351) -9 dBm (275 mV RMS) [0 dBm = 1 mW ( 0.775V RMS) in 600 ohms.
969:
front part and connected to filtered terminals on the back of the filter. The DSL modem (which at the time was also BT supplied) and, if present, a phone or plug-in extension, could then be plugged into the front. If it was desired to locate the DSL modem away from the master socket a plug-in ADSL extension kit could be purchased.
1036:, and therefore prone to electromagnetic interference and crosstalk with nearby other wiring. It is modern practice to remove the bell wire to rebalance the circuit and thus reduce potential interference from office or far field RF interference. The telephone is plugged at the other end into the structured cabling via a
742:
is required to do this and two sorts are available. One is of plastic construction and only intended for occasional use. The other is a professional tool used by installers, which is a spring loaded push down tool that both inserts the wire and trims it in one action : an example is shown in the
345:
and Bell Wire noise suppression. The vDSL modem now plugs directly into the 6P6C modular socket on the faceplate. The faceplate can be easily fitted by removing the two bottom screws on a NTE5, sliding the bottom section out and fitting this in between. The result is that the entire extension circuit
258:
the socket: the lower half of the front plate and associated wiring is the customer's, while the permanent wiring on the non-removable section behind this, remains the responsibility of the service provider. Customers are not permitted to access the wiring in a master socket without a removable lower
859:
Strictly speaking, a textbook installation will only actually use pins 2, 5 (for the voice) and 3 (for the ringer). Having said this, most modern telephones no longer require a ringing capacitor may have 2-wire connections, which means that extension wiring can usually be run with only pins 2 and 5.
518:
The BS 6312 specification defines the terminal numbering of a socket-outlet in the opposite direction to the pin numbers of the socket. Thus terminal 1 is connected to pin 6, terminal 2 to pin 5 and so on. The pins of the 631A plug are numbered in ascending order from left to right with the contacts
329:
between the internal/domestic wiring (at the removable front of the socket which is the customer's responsibility) and the external telephone line/cabling fixed at the rear (which is BT's responsibility) the physical disconnection of the two sets of wires (made possible by the NTE5's removable front
291:
leg voltage. The exact voltage drop is a function of the distance to the exchange, and the network wiring type. According to SIN 352 the average DC current in the loop and voltage across the phone will be up to 42 mA at 12.5 V (short line), up to 33.5 mA at 10 V, and will be not less than 25 mA at 9
1062:
There exists no well-established standard in which polarity pins 2 and 5 of the phone socket are connected to pins 4 and 5 of the 8P8C connector; both alternatives are common. This polarity is not normally important; BT does specify that the B wire is more negative than the A, though they no longer
1027:
pair 1 in Cat5 cables). In most other countries, those two wires are all that is needed to connect an analogue telephone. In the UK, however, many telephone circuits still have an anti-tinkle connection between the master socket and extensions on a third wire. But such a 3-wire interface is not the
968:
When ADSL was first introduced in the UK it was installed by a technician who replaced the front part of the NTE5 (if the property still had an old style master socket it would be replaced with an NTE5) with one containing a filter. Any hardwired phone extensions were disconnected from the original
964:
All phones (or other voice band devices) must be connected via a filter (either a separate filter for each phone or one filter covering multiple phones) to avoid interference between the phones and the DSL signal. If the data transmission is still audible the use of two DSL filters, daisychained in
514:
The 631A and 630A plugs are also used for connecting sensors to interfaces for computer-based measurements in educational environments, the former for connecting analogue sensors and the latter for digital sensors. Companies using these plugs include
Vernier, TI and Casio, for interfaces connecting
324:
As BT no longer has a monopoly of internal wiring, they make a substantial charge if a fault reported to them is found to be in the customer's internal/domestic wiring. It is therefore important for the customer to have the facility to check whether a fault is in their internal wiring/equipment or
209:
in 1959, when a smaller "Plug 420" was introduced. The separate bell-set, with its on-board capacitor and coils, also provided a testing circuit for remote engineers, by providing the mandatory 1000 ohm capacitive loop-back. Rental had to be paid on each telephone and on all the sockets, and hence
312:
The 'old style' fixed master socket had only one set of terminals on the back and customers were supposed to use extension kits plugged into the front socket; however, many customers hard-wired their own extensions anyway for neatness and robustness reasons, which was a poor arrangement since it
973:
understand. The more discerning customer can purchase a variety of hardwired filtering products, including replacement front plates for the NTE5, some of which have unfiltered as well as filtered terminals on the back to avoid the need to plug in the extension wiring that leads to the DSL modem.
300:
speeds. The socket includes a 1.8 μF capacitor (bell circuit) to feed the AC ringing and a 470 kΩ resistor (R1, out-of-service resistor) to permit remote testing when no telephones are plugged into any sockets. Additional internal extension (secondary) sockets are wired off the master
829:
Shown below are the cabling arrangements for both 4-wire and 6-wire cable. Initially 4-wire was used and many older installations still use it, then the 6-wire became the new standard, but the 4-wire has latterly been reissued to all
Openreach technicians as part of cost savings. Modern 4-wire
316:
NTE5 Linebox sockets have for many years been fitted in place of master sockets. The lower part of the front plate can be removed after unscrewing two screws, allowing users access to the terminals required for connecting internal extension sockets. The removable panel also allows the external
972:
BT also offered "wires-only" ADSL service and promoted the technique of using a separate plug-in filter on every socket. While both technically inferior and far less tidy than the solution BT engineers had used, it was usually adequate and was simple enough for a non-technical householder to
196:
From the early years of the 1900s, the GPO (subsequently
British Telecom) had a plug and socket system available for rent. It was later called a "Plan 4" (N762—first edition), and employed a heavy-duty, four-way jack plug 404 (circular in cross-section), on the end of the standard, plaited,
542:
from the BT plug (which uses pins 2 and 5 for the line, unlike RJ11, which uses pins 3 and 4). Thus cables are not in general compatible between different phones, as the phone base may have a socket with pins 2 and 5 (requiring a straight-through cable), or have an RJ11 socket (requiring a
571:
for telephone as well as data services. Since 2010 the
Telecommunications Carriers Forum Premises Wiring Code of Practice has deprecated BT jacks in favour of "RJ45" modular jacks for all new residential and SOHO phone/data networks, although not yet a mandatory standard in 2016.
943:
192:
telephone-engineer, who needed a complete set of 'N' (wiring) Diagrams, which was very extensive and ran to over 15 volumes of little black ring binders. N diagrams also had their own numbering system (e.g., a Plan 1A had an N diagram of N4502), and were frequently updated.
507:
431A is 4-way and 631A 6-way. There are also plugs with only two contacts commonly seen on modem leads. These are a recent introduction and do not seem to be easily available as separate parts. All fit any right-handed "Type 600" telephone socket.
999:
systems are general-purpose communications wires installed in offices and increasingly also homes, which can be used for several different communication technologies (analog phone, ADSL, ISDN, Ethernet, video, etc.). The most common type uses
706:, Irish, Malaysian and Singaporean phone jacks bear some varying levels of similarity to their UK cousins due to GPO influences in the old Irish, Malaysian and Singaporean phone wiring systems. The Malaysian Telecommunications Department (now
184:, could be connected to the network, rather than British Telecom controlling the market. The 'New Plan' was only new to the UK and was based extensively on systems which had been available elsewhere for many years, especially in the US.
3148:
43:. Electrical characteristics of the telephone interface are specified by individual network operators, e.g. in British Telecom's SIN 351. Electrical characteristics required of British telephones used to be specified in
187:
The new system replaced the older hard-wired system, which came in many 'flavours' (e.g., Plans 1, 1A, 1B, 1C, 2, 2A, 105, 107 etc.), which could be very complicated and required the attendance at the premises of a
1233:
1206:
1120:
BS 6312-2.2:1997. Connectors for analogue telecommunication interfaces. Sockets for use with plugs specified in BS 6312-1. Particular requirements for fixed socket-outlets used in permanent wiring installations.
295:
Until recently, this socket contained an enclosed spark gap, SP1, that could safely flash over internally to provide high voltage surge protection. This component is no longer used due to negative effects on
2319:
511:
Type 430A and 630A plugs have the latch on the opposite (left hand) side of the plug, and were used as headset plugs on some switchboards and as handset connectors on some telephones, e.g. Ambassador.
1359:
The RJ System of telephone plugs and sockets is gradually replacing the BT System in Hong Kong, Office of the
Telecommunications Authority (OFTA), Hong Kong Special Administrative Region Government
1063:
specify which of the A and B wires are connected to pins 2 and 5 of their master telephone socket, although earlier standards specified that the A wire be connected to 5 and the B wire to 2.
242:
A domestic single
British telephone line installation will have a single master socket or line box in the premises, which is provided by BT or another service provider: this socket is the
3033:
1163:
BS 6305:1992. Specification for general requirements for apparatus for connection to public switched telephone networks run by certain public telecommunication operators. (obsolescent)
279:
leg to pin 2 in the master socket. (Although all equipment will work with a reversed line, so a reverse wired socket is not strictly a fault.) When current is flowing on the line, the
3203:
2312:
346:
is filtered by the vDSL plate, so that DSL filters are no longer needed on a telephone socket used for DSL. The vDSL Interstitial
Faceplate can also be fitted to lines used for
1111:
BS 6312-2.1:1994. Connectors for analogue telecommunication interfaces. Sockets for use with plugs specified in BS 6312:Part 1. Specification for sockets. General requirements.
753:
743:
photograph. It also comes with a tool for removing wires from sockets. From Q3 2016, Openreach started using a new, "toolless" version of the demarcation socket—the
1229:
1213:
2305:
3349:
201:, which was permanently in-circuit to provide ringing if there were no telephones plugged in. This system survived through various models of telephones from the "
3069:
1023:
The A and B wires of an analogue phone line appear in a structured cabling system usually on the centre pins of the 8P8C connector (pins 4 and 5; the blue/white
3074:
563:
wiring that eliminated the 3rd anti-tinkling wire. The "BT Jack" is still the most common phone jack in use, although many installations in business use
3208:
527:
The connector on the phone is not standardized: the connector at the wall is standardized by regulation, to allow individuals to use their own phones (
176:
Standard sockets were introduced, as part of the 'New Plan' wiring policy, to allow customers to easily purchase their own telephones, as required by
3336:
1249:
3153:
559:
since the 1980s, replacing a number of other connectors and hard-wired connections, and was subsequently replaced by a "2-wire" version suited to
222:
A fixed BT Master Socket front LJ 2/1A that does not allow disconnection of internal wiring with previous 1980–1991 BT "T" logo - surface mounted
3236:
1291:
181:
1358:
1274:
3271:
259:
section. Plug-in extension kits are available for customers with this type of installation. The two wires from the exchange are denoted the
2763:
2344:
1343:
538:
at the telephone end: this latter may be wired as per the RJ11 standard (with pins 3 and 4), or it may be wired with pins 2 and 5, as a
3193:
3163:
1278:
136:
3028:
2254:
2249:
2123:
895:
108:
89:
1129:
3158:
2328:
860:
Often where multi-core cable is used, the remaining cables are used for wiring extensions on additional incoming telephone lines.
801:
3306:
3281:
2758:
813:
1058:
PSTN master: implements all the circuitry found in a BT master socket, including surge protection, ring capacitor, test resistor
115:
3138:
3381:
3178:
3038:
2138:
1304:
1353:
765:
560:
180:, the phone regulator. Thus any phone whose plug conformed to BS 6312 and met certain other regulatory standards, such as
122:
3241:
2873:
1550:
1530:
3316:
3198:
2520:
2118:
2072:
1812:
1385:
1055:
PABX master: contains ring capacitor, to provide from the 8P8C 2-wire interface the 3rd bell wire required by UK phones
2808:
2128:
1966:
1822:
1817:
1797:
921:
735:
719:
556:
353:
There are several versions of the NTE5 (e.g., NTE5, NTE5a, NTE5c) and of the vDSL Interstitial
Faceplate (Mk2, Mk3).
318:
306:
155:
104:
903:
3311:
3188:
3128:
1077:
684:
3168:
3089:
2244:
1535:
1147:
777:
3286:
3173:
3123:
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899:
93:
3376:
3143:
3048:
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2462:
2339:
2067:
1424:
251:
3118:
1145:
BT Public
Switched Telephone Network (PSTN): technical characteristics of the single analogue line interface
3183:
3110:
2229:
1946:
1807:
1048:
that contains the capacitor needed to connect the bell signal. Different types of LAUs are on the market:
3132:
3023:
2858:
2848:
1916:
1802:
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1253:
309:
system) but not containing the surge protector, bell circuit capacitor, and the out-of-service resistor.
2818:
2778:
2748:
2198:
1911:
1862:
531:), but the wire from the phone to the wall may be hard-wired to the phone, or use various connectors.
129:
3246:
2379:
2284:
1921:
1893:
1434:
2297:
341:, and at the same time introduced the BT vDSL Interstitial Faceplate, which performs two functions:
58:), but have a side-mounted hook, rather than a bottom-mounted one, and are physically incompatible.
3256:
3084:
2853:
2510:
2062:
2037:
980:
NTE5 showing it being fitted with a BT IPlate. The IPlate is the part in the middle of the sandwich
884:
723:
3213:
3266:
2768:
2476:
2224:
2057:
1630:
1625:
1449:
888:
789:
82:
2591:
1594:
2961:
2813:
1956:
1941:
1857:
1847:
1782:
1378:
1321:
539:
330:
plate) is crucial in identifying faults and allocating responsibility for their rectification.
2042:
1275:
The RJ System of telephone plugs and sockets is gradually replacing the BT System in Hong Kong
1102:
BS 6312-1:1994. Connectors for analogue telecommunication interfaces. Specification for plugs.
836:
2686:
2374:
1936:
1842:
1767:
1752:
1480:
1174:
202:
1525:
848:
2798:
2153:
2077:
1827:
759:
Krone IDC Tool, showing the wire removal tool open officially known as
Inserter Wire No. 2a
668:
2497:
568:
8:
2838:
2793:
2439:
2193:
1961:
1931:
1787:
695:
189:
206:
3301:
3296:
3105:
3094:
2996:
2878:
2469:
1872:
1837:
1777:
1772:
1681:
1429:
996:
564:
247:
1898:
313:
provided no way to isolate the customer's internal extension wiring from BT's wiring.
168:
36:
to allow subscribers to connect their own telephones. The connectors are specified in
3371:
3276:
2584:
2272:
1867:
1852:
1371:
1033:
535:
326:
325:
externally in BT's cabling or systems. Since the NTE5 socket represents the official
302:
243:
51:
985:
2823:
2803:
2541:
2414:
1951:
1832:
1792:
1072:
1013:
1001:
707:
604:
37:
1308:
3064:
2956:
2659:
2515:
2239:
1237:
1151:
739:
688:
544:
528:
501:
55:
250:, and the telephone network. For installations using the NTE5 line box (NTE for
2642:
2578:
1686:
1083:
365:
British telephone plug with only two pins present (2 and 5), from a modem cable
21:
3365:
3291:
3231:
2946:
2788:
2753:
2743:
2565:
2409:
2052:
1926:
1747:
1570:
32:
were introduced in their current plug and socket form on 19 November 1981 by
1348:
2905:
2727:
2679:
2611:
2606:
2491:
2188:
2133:
2001:
1903:
1716:
1711:
1706:
1645:
1620:
1520:
1510:
1154:, British Telecom, Suppliers Information Note SIN 351, Issue 4.5, May 2006.
1005:
660:
453:
435:
490:
398:
3251:
2868:
2702:
2616:
2598:
2455:
2444:
2214:
1696:
1540:
1439:
1419:
1290:
Initial provisions were usually NTE5, with a new faceplate, but previous
1024:
1017:
715:
472:
417:
338:
2915:
2863:
2722:
2709:
2554:
2535:
2389:
1701:
1691:
1671:
1495:
1459:
958:
957:
services simultaneously with voice telephony, it is necessary to use a
718:-style 6P2C plugs and 6P4C "RJ11" sockets in the 1970s, with Ireland's
580:
342:
198:
96: in this section. Unsourced material may be challenged and removed.
1144:
2828:
2559:
2404:
2399:
2384:
2327:
2219:
1757:
1676:
1666:
1464:
1444:
951:
703:
680:
612:
3034:
European Conference of Postal and Telecommunications Administrations
946:
Replacement face plate for an NTE5 containing a built-in ADSL filter
873:
747:—which does not require an IDC tool to make the connections.
271:
leg which is near ground potential when the line is not in use. The
71:
2971:
2966:
2920:
2717:
2696:
2672:
2637:
2622:
2530:
2505:
2449:
2394:
2148:
2087:
2082:
1991:
1762:
1580:
1575:
1485:
1394:
1080:, influenced by British standards as introduced during British rule
1029:
954:
699:
676:
664:
588:
361:
33:
504:
plugs in common use for connecting telephones, the 431A and 631A.
25:
BS 6312 431A plug, colloquially a British Telecom 4-wire male plug
2925:
2783:
2665:
2525:
2483:
2158:
2102:
2097:
2092:
2032:
1640:
1565:
1560:
1555:
1515:
1502:
1454:
1212:(Report). 2.9. Openreach. September 2020. SIN 352. Archived from
711:
648:
644:
632:
600:
576:
205:" 200 and 300 type Bakelite phones until the introduction of the
984:
In 2008 BT trialled and launched their 'IPlate'; the "I" is for
2930:
2629:
2549:
2369:
2143:
1986:
1877:
1545:
672:
636:
628:
620:
616:
596:
592:
584:
234:
197:
cotton-covered instrument cord. It also had to have a separate
1305:"Colour chart for telephone wiring over CAT5 cables (UK / US)"
976:
734:
As previously mentioned the actual connections are made using
3261:
3079:
3043:
2910:
2843:
2833:
2573:
2234:
1996:
1981:
1976:
1971:
1635:
1045:
934:
656:
640:
624:
608:
177:
942:
515:
to their graphical calculators, and in the Netherlands CMA.
350:, for which it has been shown to improve connection speeds.
3001:
1490:
1363:
1009:
652:
347:
334:
297:
226:
218:
1281:(OFTA), Hong Kong Special Administrative Region Government
2168:
2163:
267:
V relative to ground when the line is not in use and the
1052:
PSTN secondary/slave: for phones that need no bell wire
519:
facing upwards and the latch on the right-hand side.
710:) and Telecommunication Authority of Singapore (now
1252:. Telecommunications Carriers Forum. Archived from
819:
LJ 2/1A - 6 wire cable connected to a master socket
807:
LJ 2/1A - 4 wire cable connected to a master socket
683:, where new installations ceased in 1998, while in
619:(but wired differently from the British Standard),
3075:Internet Telephony Services Providers' Association
2329:Telecommunications industry in the United Kingdom
3363:
1294:(ISDN-like) installations received microfilters.
1193:Connections of Telephonic Apparatus and Circuits
1130:Publication of Customer Interface Specifications
283:leg voltage collapses to nearer ground and the
3237:British Approvals Board for Telecommunications
2313:
1379:
238:BT fibre-to-the-cabinet (FTTC) VDSL faceplate
2345:Science and technology in the United Kingdom
1354:Using ADSL with extension telephone sockets
1322:"BT claims UK broadband boost breakthrough"
1207:BT Public Switched Telephone Network (PSTN)
902:. Unsourced material may be challenged and
783:4 wire cable the old sort, but much thinner
2809:London & Provincial District Telegraph
2320:
2306:
1386:
1372:
1279:Office of the Telecommunications Authority
246:between the customer-owned and maintained
3029:Defence Science and Technology Laboratory
2255:British Telecommunications plc v. Prodigy
2250:Young Scientist and Technology Exhibition
2124:Digital Private Network Signalling System
922:Learn how and when to remove this message
771:Plastic IDC Tool, for occasional use only
729:
687:, new installations ceased in 2001, with
550:
156:Learn how and when to remove this message
3204:South Georgia and South Sandwich Islands
1140:
1138:
975:
941:
933:
360:
233:
225:
217:
167:
20:
3282:Interception of Communications Act 1985
1195:. Post Office Telegraph. 1909. Plate 3.
1185:
824:
3364:
3070:Internet Service Providers Association
1223:
534:Typically it will have a 6P4C or 6P2C
3039:International Telecommunication Union
2301:
2139:International Packet Switched Service
1367:
1199:
1157:
1135:
1012:(colloquially and incorrectly called
991:
694:While BS 6312 was not adopted in the
522:
254:), the demarcation point is actually
3343:
2764:British and Irish Magnetic Telegraph
2759:Bonelli's Electric Telegraph Company
2280:
900:adding citations to reliable sources
867:
94:adding citations to reliable sources
65:
3242:British Telecommunications Act 1981
13:
2119:Digital Access Signalling System 1
2073:Digital Access Signalling System 2
1813:National Network Management Centre
1250:"Premises Wiring Code of Practice"
1172:
736:Insulation-displacement connectors
555:The BS 6312 jack has been used in
319:insulation-displacement connectors
14:
3393:
2129:Fixed-Mobile Convergence Alliance
1823:Zouches Farm transmitting station
1818:Peterborough transmitting station
1337:
3342:
3330:
3329:
3312:UK telephone code misconceptions
2279:
2268:
2267:
1593:
1078:Technical standards in Hong Kong
1008:with 100 ohm impedance) between
872:
847:
835:
812:
800:
788:
776:
764:
752:
685:Saint Vincent and the Grenadines
489:
471:
452:
434:
416:
397:
287:leg voltage moves nearer to the
210:the system was not that common.
70:
1536:Concert Communications Services
1297:
1284:
1268:
1242:
1028:symmetric interface needed for
81:needs additional citations for
16:Type of telephone socket design
3149:British Indian Ocean Territory
2774:Cable & Wireless Worldwide
1551:International Network Services
1324:. The Register. 1 October 2008
1166:
1123:
1114:
1105:
1096:
500:There are two types of modern
1:
3049:Phone-paid Services Authority
2463:BT Business and Public Sector
2340:Economy of the United Kingdom
2068:Digital Access Carrier System
1425:BT Business and Public Sector
1349:UK plug and socket telephones
1016:) room sockets and a central
795:6 wire cable the current type
679:. The jack is still found in
252:network termination equipment
3382:Telecommunications equipment
3111:British Overseas Territories
2230:BT Sport Action Woman Awards
1947:Post Office Research Station
1808:Madley Communications Centre
1803:Guardian Exchange Manchester
1393:
863:
7:
3133:British Antarctic Territory
3024:Broadband Stakeholder Group
2874:Universal Private Telegraph
1917:Kingsway telephone exchange
1066:
337:service to the UK known as
10:
3398:
2819:National Telephone Company
2779:Electric Telegraph Company
2749:Atlantic Telegraph Company
2199:Electric Telegraph Company
1863:Wotton-under-Edge BT Tower
275:leg goes to pin 5 and the
213:
172:GPO Plan 4 socket and plug
105:"British telephone socket"
61:
3325:
3247:British telephone sockets
3222:
3103:
3057:
3014:
2989:
2939:
2898:
2891:
2736:
2432:
2423:
2380:BT Wholesale and Ventures
2360:
2353:
2335:
2263:
2207:
2181:
2111:
2025:
2014:
1942:Sheffield Telephone House
1922:Leafield Technical Centre
1894:Anchor telephone exchange
1886:
1740:
1729:
1659:
1613:
1602:
1591:
1473:
1435:BT Wholesale and Ventures
1412:
1401:
1230:Help and support document
383:
30:British telephone sockets
3257:BT site engineering code
3209:Turks and Caicos Islands
3085:London Internet Exchange
2769:Cable & Wireless plc
2063:Advanced Mobile Location
2048:British telephone socket
2038:BT site engineering code
1175:"Post Office N-diagrams"
1089:
356:
333:In 2009 BT Introduced a
3307:Telephone numbers in UK
3267:Communications Act 2003
2225:BT Digital Music Awards
2058:Customer Service System
569:8P8C modular connectors
3154:British Virgin Islands
2962:Marconi Communications
1957:Criggion Radio Station
1858:Tolsford Hill BT Tower
1848:Sutton Common BT Tower
1150:June 17, 2013, at the
981:
947:
939:
730:Making the connections
551:Use in other countries
540:straight-through cable
366:
239:
231:
223:
173:
26:
3119:Akrotiri and Dhekelia
2687:Virgin Media Business
2375:Babcock International
1843:Stokenchurch BT Tower
1768:BT Tower (Birmingham)
979:
945:
937:
364:
301:socket (connected in
237:
229:
221:
171:
24:
3377:Telephone connectors
3272:Earth stations in UK
2799:Gutta Percha Company
2521:Cable & Wireless
2440:Andrews & Arnold
2154:Packet Switch Stream
1828:Heaton Park BT Tower
896:improve this section
825:Cabling arrangements
669:United Arab Emirates
90:improve this article
50:They are similar to
2859:Submarine Telegraph
2794:General Post Office
2194:General Post Office
1962:Rugby Radio Station
1932:Stag Lane Aerodrome
1788:Charwelton BT Tower
1236:8 June 2021 at the
1179:www.samhallas.co.uk
696:Republic of Ireland
575:It is also used in
431:External Bell wire
371:
230:NEW BT NTE5 in 2016
3317:Web blocking in UK
3302:Telegraph Act 1885
3297:Telegraph Act 1868
3106:Crown Dependencies
3095:Symbian Foundation
2997:Carphone Warehouse
2470:BT Global Services
1873:KX telephone boxes
1838:Pye Green BT Tower
1798:Goonhilly Cornwall
1778:BT Riverside Tower
1773:BT Tower (Swansea)
1682:BT Superfast Fibre
1430:BT Global Services
1034:transmission lines
997:Structured cabling
992:Structured cabling
982:
948:
940:
691:now used instead.
565:structured cabling
523:Connector on phone
369:
367:
248:on-premises wiring
240:
232:
224:
174:
52:modular connectors
27:
3359:
3358:
3277:Hull Colour Pages
3017:regulatory bodies
3010:
3009:
2985:
2984:
2887:
2886:
2712:
2705:
2689:
2682:
2675:
2668:
2654:
2649:
2632:
2625:
2601:
2594:
2587:
2568:
2544:
2500:
2486:
2479:
2472:
2465:
2458:
2295:
2294:
2177:
2176:
2043:BT Speaking Clock
2010:
2009:
1967:Microwave network
1868:Red telephone box
1853:Tinshill BT Tower
1763:BT Tower (London)
1725:
1724:
1589:
1588:
1505:
1311:on 22 April 2016.
1038:line adapter unit
1002:Category 5 cables
932:
931:
924:
842:Four wire cabling
536:modular connector
498:
497:
327:demarcation point
244:demarcation point
166:
165:
158:
140:
3389:
3346:
3345:
3333:
3332:
3214:Tristan da Cunha
3194:Pitcairn Islands
3164:Falkland Islands
3139:Ascension Island
2896:
2895:
2708:
2701:
2685:
2678:
2671:
2664:
2652:
2647:
2628:
2621:
2597:
2590:
2583:
2564:
2542:Eclipse Internet
2540:
2516:The Co-operative
2496:
2482:
2475:
2468:
2461:
2454:
2430:
2429:
2415:Telehouse Europe
2358:
2357:
2322:
2315:
2308:
2299:
2298:
2283:
2282:
2271:
2270:
2023:
2022:
1952:Portishead Radio
1833:Purdown BT Tower
1793:Faraday Building
1738:
1737:
1611:
1610:
1597:
1500:
1410:
1409:
1388:
1381:
1374:
1365:
1364:
1333:
1331:
1329:
1313:
1312:
1307:. Archived from
1301:
1295:
1288:
1282:
1272:
1266:
1265:
1263:
1261:
1246:
1240:
1232:openreach.co.uk
1227:
1221:
1220:
1218:
1211:
1203:
1197:
1196:
1189:
1183:
1182:
1170:
1164:
1161:
1155:
1142:
1133:
1127:
1121:
1118:
1112:
1109:
1103:
1100:
1073:RJ11, RJ14, RJ25
950:In order to use
927:
920:
916:
913:
907:
876:
868:
854:Six wire cabling
851:
839:
816:
804:
792:
780:
768:
756:
708:Telekom Malaysia
605:Falkland Islands
603:, Eswatini, the
493:
475:
456:
438:
420:
401:
372:
368:
266:
161:
154:
150:
147:
141:
139:
98:
74:
66:
38:British Standard
3397:
3396:
3392:
3391:
3390:
3388:
3387:
3386:
3362:
3361:
3360:
3355:
3321:
3224:
3218:
3109:
3099:
3065:GSM Association
3058:Industry bodies
3053:
3016:
3006:
2981:
2957:Marconi Company
2935:
2883:
2732:
2660:Virgin Media O2
2425:
2419:
2362:
2349:
2331:
2326:
2296:
2291:
2259:
2240:Connected Earth
2203:
2173:
2107:
2018:
2016:
2006:
1882:
1733:
1731:
1721:
1655:
1606:
1604:
1598:
1585:
1469:
1405:
1403:
1397:
1392:
1340:
1327:
1325:
1320:
1317:
1316:
1303:
1302:
1298:
1289:
1285:
1273:
1269:
1259:
1257:
1248:
1247:
1243:
1238:Wayback Machine
1228:
1224:
1219:on 8 June 2021.
1216:
1209:
1205:
1204:
1200:
1191:
1190:
1186:
1171:
1167:
1162:
1158:
1152:Wayback Machine
1143:
1136:
1128:
1124:
1119:
1115:
1110:
1106:
1101:
1097:
1092:
1069:
994:
928:
917:
911:
908:
893:
877:
866:
855:
852:
843:
840:
827:
820:
817:
808:
805:
796:
793:
784:
781:
772:
769:
760:
757:
740:punch down tool
732:
645:Myanmar (Burma)
553:
545:crossover cable
529:interconnection
525:
502:British Telecom
359:
264:
216:
162:
151:
145:
142:
99:
97:
87:
75:
64:
34:British Telecom
17:
12:
11:
5:
3395:
3385:
3384:
3379:
3374:
3357:
3356:
3354:
3353:
3340:
3326:
3323:
3322:
3320:
3319:
3314:
3309:
3304:
3299:
3294:
3289:
3287:Internet in UK
3284:
3279:
3274:
3269:
3264:
3259:
3254:
3249:
3244:
3239:
3234:
3228:
3226:
3220:
3219:
3217:
3216:
3211:
3206:
3201:
3196:
3191:
3186:
3181:
3176:
3171:
3166:
3161:
3159:Cayman Islands
3156:
3151:
3146:
3141:
3136:
3126:
3121:
3115:
3113:
3101:
3100:
3098:
3097:
3092:
3087:
3082:
3077:
3072:
3067:
3061:
3059:
3055:
3054:
3052:
3051:
3046:
3041:
3036:
3031:
3026:
3020:
3018:
3015:Government and
3012:
3011:
3008:
3007:
3005:
3004:
2999:
2993:
2991:
2987:
2986:
2983:
2982:
2980:
2979:
2974:
2969:
2964:
2959:
2954:
2949:
2943:
2941:
2937:
2936:
2934:
2933:
2928:
2923:
2918:
2913:
2908:
2902:
2900:
2893:
2889:
2888:
2885:
2884:
2882:
2881:
2876:
2871:
2866:
2861:
2856:
2851:
2846:
2841:
2836:
2831:
2826:
2821:
2816:
2811:
2806:
2801:
2796:
2791:
2786:
2781:
2776:
2771:
2766:
2761:
2756:
2751:
2746:
2740:
2738:
2734:
2733:
2731:
2730:
2725:
2720:
2715:
2714:
2713:
2706:
2694:
2693:
2692:
2691:
2690:
2676:
2669:
2657:
2656:
2655:
2650:
2643:Trunk Networks
2640:
2635:
2634:
2633:
2626:
2614:
2609:
2604:
2603:
2602:
2595:
2588:
2576:
2571:
2570:
2569:
2557:
2552:
2547:
2546:
2545:
2533:
2528:
2523:
2518:
2513:
2508:
2503:
2502:
2501:
2489:
2488:
2487:
2480:
2473:
2466:
2459:
2447:
2442:
2436:
2434:
2427:
2421:
2420:
2418:
2417:
2412:
2407:
2402:
2397:
2392:
2387:
2382:
2377:
2372:
2366:
2364:
2361:Infrastructure
2355:
2351:
2350:
2348:
2347:
2342:
2336:
2333:
2332:
2325:
2324:
2317:
2310:
2302:
2293:
2292:
2290:
2289:
2277:
2264:
2261:
2260:
2258:
2257:
2252:
2247:
2242:
2237:
2232:
2227:
2222:
2217:
2211:
2209:
2205:
2204:
2202:
2201:
2196:
2191:
2185:
2183:
2179:
2178:
2175:
2174:
2172:
2171:
2166:
2161:
2156:
2151:
2146:
2141:
2136:
2131:
2126:
2121:
2115:
2113:
2109:
2108:
2106:
2105:
2100:
2095:
2090:
2085:
2080:
2075:
2070:
2065:
2060:
2055:
2050:
2045:
2040:
2035:
2029:
2027:
2020:
2012:
2011:
2008:
2007:
2005:
2004:
1999:
1994:
1989:
1984:
1979:
1974:
1969:
1964:
1959:
1954:
1949:
1944:
1939:
1934:
1929:
1924:
1919:
1914:
1909:
1901:
1899:Bletchley Park
1896:
1890:
1888:
1884:
1883:
1881:
1880:
1875:
1870:
1865:
1860:
1855:
1850:
1845:
1840:
1835:
1830:
1825:
1820:
1815:
1810:
1805:
1800:
1795:
1790:
1785:
1780:
1775:
1770:
1765:
1760:
1755:
1750:
1744:
1742:
1735:
1727:
1726:
1723:
1722:
1720:
1719:
1714:
1709:
1704:
1699:
1694:
1689:
1687:BT Versatility
1684:
1679:
1674:
1669:
1663:
1661:
1657:
1656:
1654:
1653:
1648:
1643:
1638:
1633:
1628:
1623:
1617:
1615:
1608:
1600:
1599:
1592:
1590:
1587:
1586:
1584:
1583:
1578:
1573:
1568:
1563:
1558:
1553:
1548:
1543:
1538:
1533:
1528:
1523:
1518:
1513:
1508:
1507:
1506:
1493:
1488:
1483:
1477:
1475:
1471:
1470:
1468:
1467:
1462:
1457:
1452:
1447:
1442:
1437:
1432:
1427:
1422:
1416:
1414:
1407:
1399:
1398:
1391:
1390:
1383:
1376:
1368:
1362:
1361:
1356:
1351:
1346:
1344:Wiring diagram
1339:
1338:External links
1336:
1335:
1334:
1315:
1314:
1296:
1283:
1267:
1256:on 2 June 2010
1241:
1222:
1198:
1184:
1165:
1156:
1134:
1122:
1113:
1104:
1094:
1093:
1091:
1088:
1087:
1086:
1084:GPO telephones
1081:
1075:
1068:
1065:
1060:
1059:
1056:
1053:
993:
990:
930:
929:
880:
878:
871:
865:
862:
857:
856:
853:
846:
844:
841:
834:
826:
823:
822:
821:
818:
811:
809:
806:
799:
797:
794:
787:
785:
782:
775:
773:
770:
763:
761:
758:
751:
731:
728:
552:
549:
524:
521:
496:
495:
487:
484:
482:
478:
477:
469:
466:
463:
459:
458:
450:
447:
445:
441:
440:
432:
429:
427:
423:
422:
414:
411:
408:
404:
403:
395:
392:
390:
386:
385:
382:
379:
376:
370:BT631A wiring
358:
355:
215:
212:
164:
163:
146:September 2016
78:
76:
69:
63:
60:
15:
9:
6:
4:
3:
2:
3394:
3383:
3380:
3378:
3375:
3373:
3370:
3369:
3367:
3352:
3351:
3341:
3339:
3338:
3328:
3327:
3324:
3318:
3315:
3313:
3310:
3308:
3305:
3303:
3300:
3298:
3295:
3293:
3292:Telegraph Act
3290:
3288:
3285:
3283:
3280:
3278:
3275:
3273:
3270:
3268:
3265:
3263:
3260:
3258:
3255:
3253:
3250:
3248:
3245:
3243:
3240:
3238:
3235:
3233:
3232:Adastral Park
3230:
3229:
3227:
3221:
3215:
3212:
3210:
3207:
3205:
3202:
3200:
3197:
3195:
3192:
3190:
3187:
3185:
3182:
3180:
3177:
3175:
3172:
3170:
3167:
3165:
3162:
3160:
3157:
3155:
3152:
3150:
3147:
3145:
3142:
3140:
3137:
3134:
3130:
3127:
3125:
3122:
3120:
3117:
3116:
3114:
3112:
3107:
3102:
3096:
3093:
3091:
3088:
3086:
3083:
3081:
3078:
3076:
3073:
3071:
3068:
3066:
3063:
3062:
3060:
3056:
3050:
3047:
3045:
3042:
3040:
3037:
3035:
3032:
3030:
3027:
3025:
3022:
3021:
3019:
3013:
3003:
3000:
2998:
2995:
2994:
2992:
2988:
2978:
2975:
2973:
2970:
2968:
2965:
2963:
2960:
2958:
2955:
2953:
2950:
2948:
2945:
2944:
2942:
2938:
2932:
2929:
2927:
2924:
2922:
2919:
2917:
2914:
2912:
2909:
2907:
2904:
2903:
2901:
2897:
2894:
2890:
2880:
2879:Virgin Mobile
2877:
2875:
2872:
2870:
2867:
2865:
2862:
2860:
2857:
2855:
2852:
2850:
2847:
2845:
2842:
2840:
2837:
2835:
2832:
2830:
2827:
2825:
2822:
2820:
2817:
2815:
2812:
2810:
2807:
2805:
2802:
2800:
2797:
2795:
2792:
2790:
2787:
2785:
2782:
2780:
2777:
2775:
2772:
2770:
2767:
2765:
2762:
2760:
2757:
2755:
2754:Be Un Limited
2752:
2750:
2747:
2745:
2742:
2741:
2739:
2735:
2729:
2726:
2724:
2721:
2719:
2716:
2711:
2707:
2704:
2700:
2699:
2698:
2695:
2688:
2684:
2683:
2681:
2677:
2674:
2670:
2667:
2663:
2662:
2661:
2658:
2651:
2646:
2645:
2644:
2641:
2639:
2636:
2631:
2627:
2624:
2620:
2619:
2618:
2615:
2613:
2610:
2608:
2605:
2600:
2596:
2593:
2589:
2586:
2582:
2581:
2580:
2577:
2575:
2572:
2567:
2566:Sky Broadband
2563:
2562:
2561:
2558:
2556:
2553:
2551:
2548:
2543:
2539:
2538:
2537:
2534:
2532:
2529:
2527:
2524:
2522:
2519:
2517:
2514:
2512:
2509:
2507:
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2410:TelecityGroup
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2079:
2076:
2074:
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2064:
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2059:
2056:
2054:
2053:Cable jetting
2051:
2049:
2046:
2044:
2041:
2039:
2036:
2034:
2031:
2030:
2028:
2024:
2021:
2013:
2003:
2000:
1998:
1995:
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1990:
1988:
1985:
1983:
1980:
1978:
1975:
1973:
1970:
1968:
1965:
1963:
1960:
1958:
1955:
1953:
1950:
1948:
1945:
1943:
1940:
1938:
1937:Marland House
1935:
1933:
1930:
1928:
1927:Mondial House
1925:
1923:
1920:
1918:
1915:
1913:
1912:Horwood House
1910:
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1900:
1897:
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1784:
1783:Stadium House
1781:
1779:
1776:
1774:
1771:
1769:
1766:
1764:
1761:
1759:
1756:
1754:
1753:Baynard House
1751:
1749:
1748:Adastral Park
1746:
1745:
1743:
1739:
1736:
1728:
1718:
1715:
1713:
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1596:
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1574:
1572:
1571:Swindon Cable
1569:
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1215:
1208:
1202:
1194:
1188:
1180:
1176:
1173:Hallas, Sam.
1169:
1160:
1153:
1149:
1146:
1141:
1139:
1131:
1126:
1117:
1108:
1099:
1095:
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1071:
1070:
1064:
1057:
1054:
1051:
1050:
1049:
1047:
1043:
1039:
1035:
1032:twisted-pair
1031:
1026:
1021:
1019:
1015:
1011:
1007:
1006:twisted pairs
1003:
998:
989:
987:
978:
974:
970:
966:
962:
960:
956:
953:
944:
936:
926:
923:
915:
905:
901:
897:
891:
890:
886:
881:This section
879:
875:
870:
869:
861:
850:
845:
838:
833:
832:
831:
815:
810:
803:
798:
791:
786:
779:
774:
767:
762:
755:
750:
749:
748:
746:
741:
737:
727:
725:
721:
717:
713:
709:
705:
701:
697:
692:
690:
686:
682:
678:
674:
670:
666:
662:
658:
654:
650:
646:
642:
638:
634:
630:
626:
622:
618:
614:
610:
606:
602:
598:
594:
590:
586:
582:
578:
573:
570:
566:
562:
558:
548:
546:
541:
537:
532:
530:
520:
516:
512:
509:
505:
503:
492:
488:
485:
483:
480:
479:
474:
470:
467:
464:
461:
460:
457:White/orange
455:
451:
448:
446:
443:
442:
439:Orange/white
437:
433:
430:
428:
425:
424:
419:
415:
412:
409:
406:
405:
400:
396:
393:
391:
388:
387:
380:
377:
374:
373:
363:
354:
351:
349:
344:
340:
336:
331:
328:
322:
320:
314:
310:
308:
304:
299:
293:
290:
286:
282:
278:
274:
270:
262:
257:
253:
249:
245:
236:
228:
220:
211:
208:
204:
200:
194:
191:
185:
183:
179:
170:
160:
157:
149:
138:
135:
131:
128:
124:
121:
117:
114:
110:
107: –
106:
102:
101:Find sources:
95:
91:
85:
84:
79:This section
77:
73:
68:
67:
59:
57:
53:
48:
46:
42:
39:
35:
31:
23:
19:
3348:
3335:
3199:Saint Helena
2906:Arm Holdings
2728:Zen Internet
2680:Virgin Media
2607:Telecom Plus
2492:China Mobile
2285:
2273:
2134:Go!Messenger
2047:
2002:UK-Belgium 5
1905:
1717:Merlin M4000
1712:Micronet 800
1707:Telecom Gold
1646:BT Smart Hub
1626:EE Broadband
1621:BT Broadband
1526:O2 (Germany)
1521:O2 (Ireland)
1511:Manx Telecom
1501:merged into
1406:subsidiaries
1326:. Retrieved
1309:the original
1299:
1292:Home Highway
1286:
1270:
1258:. Retrieved
1254:the original
1244:
1225:
1214:the original
1201:
1192:
1187:
1178:
1168:
1159:
1125:
1116:
1107:
1098:
1061:
1041:
1037:
1022:
995:
986:interstitial
983:
971:
967:
963:
949:
918:
912:January 2012
909:
894:Please help
882:
858:
828:
744:
733:
693:
661:Saudi Arabia
574:
567:with "RJ45"
554:
533:
526:
517:
513:
510:
506:
499:
494:White/green
402:Green/white
352:
332:
323:
315:
311:
294:
288:
284:
280:
276:
272:
268:
260:
255:
241:
195:
186:
175:
152:
143:
133:
126:
119:
112:
100:
88:Please help
83:verification
80:
54:(as used in
49:
44:
40:
29:
28:
18:
3252:BT Research
3225:legislation
3179:Isle of Man
3131:(including
2952:GEC Plessey
2854:Sainsbury's
2839:Post Office
2703:Vodafone UK
2456:BT Consumer
2445:Asda Mobile
2215:BT Archives
1697:BT MyDonate
1541:Telecomsoft
1440:BT Research
1420:BT Consumer
1025:TIA/EIA-568
1018:patch panel
716:Bell System
561:daisy chain
557:New Zealand
476:White/blue
421:Blue/white
339:BT Infinity
203:candlestick
3366:Categories
3189:Montserrat
3129:Antarctica
2916:Metaswitch
2864:Tiscali UK
2723:WightFibre
2710:Talkmobile
2555:Lycamobile
2536:KCOM Group
2511:Colt Group
2390:KCOM Group
2015:Programmes
1734:facilities
1702:BT MyPlace
1692:BT Voyager
1672:BT Highway
1651:TNT Sports
1496:Madasafish
1460:BT Ireland
959:DSL filter
938:DSL Filter
714:) adopted
581:Bangladesh
343:DSL filter
305:using the
263:leg at −48
207:700 series
116:newspapers
3169:Gibraltar
2892:Suppliers
2426:providers
2405:Interxion
2400:Openreach
2385:CityFibre
2363:providers
2354:Companies
2220:BT Museum
2019:standards
1906:Sovereign
1758:BT Centre
1730:Buildings
1677:BT Mobile
1667:BT Fusion
1631:EE Mobile
1481:BT Marine
1465:BT Italia
1445:Openreach
1402:Divisions
1328:1 October
952:broadband
883:does not
864:Broadband
738:(IDC). A
704:Singapore
681:Hong Kong
613:Gibraltar
486:Reserved
449:Reserved
394:Reserved
3372:BT Group
3337:Category
3223:History,
3174:Guernsey
3124:Anguilla
2977:Standard
2972:PicoChip
2921:Sarantel
2869:T-Mobile
2718:Voipfone
2697:Vodafone
2673:Giffgaff
2648:Leetline
2623:Three UK
2585:Business
2579:TalkTalk
2531:Inmarsat
2506:Claranet
2450:BT Group
2395:Nexfibre
2274:Category
2189:BT Group
2149:N3 (NHS)
2088:ADSL Max
2083:System Y
2078:System X
1992:CANTAT-2
1607:services
1603:Products
1581:Open....
1576:6GMOBILE
1486:dabs.com
1395:BT Group
1234:Archived
1148:Archived
1132:, Ofcom.
1067:See also
1040:(LAU) /
1030:balanced
955:Internet
700:Malaysia
677:Zimbabwe
665:Tanzania
589:Botswana
321:(IDCs).
303:parallel
199:bell-set
3350:Commons
3144:Bermuda
2940:Defunct
2926:Spirent
2899:Current
2814:Mercury
2784:Energis
2737:Defunct
2526:Entanet
2484:Plusnet
2433:Current
2424:Service
2286:Commons
2182:History
2159:Prestel
2112:Defunct
2103:YouView
2098:1-5-7-1
2093:Redcare
2033:BT 21CN
2026:Current
1741:Current
1660:Defunct
1641:EE WiFi
1614:Current
1566:LineOne
1561:Telfort
1556:Dialcom
1516:O2 (UK)
1503:Plusnet
1455:Plusnet
1413:Current
1042:Mod-Tap
904:removed
889:sources
720:P&T
712:Singtel
649:Nigeria
633:Lesotho
601:Eritrea
577:Bahrain
381:Signal
214:Sockets
130:scholar
62:History
45:BS 6305
41:BS 6312
3347:
3334:
3184:Jersey
2931:Telent
2849:Rabbit
2829:Orange
2804:Ionica
2789:Family
2653:No One
2630:SMARTY
2592:Mobile
2550:Lebara
2498:CMLink
2370:Arqiva
2245:People
2144:NHSnet
1987:TAT-14
1887:Former
1878:LinkUK
1546:Tymnet
1531:Ribbit
1474:Former
1260:5 June
1004:(four
675:, and
673:Zambia
667:, the
637:Malawi
629:Kuwait
621:Jordan
617:Israel
597:Cyprus
593:Brunei
585:Belize
468:Leg B
413:Leg A
384:Color
265:
256:within
132:
125:
118:
111:
103:
3262:Buzby
3090:MaNAP
3080:LONAP
3044:Ofcom
2990:Other
2911:Icera
2844:Pipex
2834:Ovivo
2617:Three
2612:Tesco
2574:spusu
2235:Buzby
2208:Other
1997:SAT-2
1982:TAT-9
1977:TAT-8
1972:TAT-1
1636:EE TV
1217:(PDF)
1210:(PDF)
1090:Notes
1046:Molex
745:NTE5C
722:(now
657:Qatar
641:Malta
625:Kenya
609:Ghana
357:Plugs
178:Oftel
137:JSTOR
123:books
3002:Hibu
2967:Pace
1491:Hibu
1330:2008
1262:2011
1014:RJ45
1010:8P8C
887:any
885:cite
689:RJ11
653:Oman
378:Pair
348:ADSL
335:vDSL
298:VDSL
182:BABT
109:news
56:RJ11
3108:and
3104:In
2947:CSR
2824:NTL
2744:AOL
2638:Tru
2560:Sky
2169:TXK
2164:TXE
2017:and
1904:CS
1732:and
1605:and
1404:and
898:by
724:Eir
702:or
547:).
375:Pin
307:IDC
190:GPO
92:by
3368::
2666:O2
2599:TV
2477:EE
1450:EE
1277:,
1177:.
1137:^
1044:/
1020:.
698:,
671:,
663:,
659:,
655:,
651:,
647:,
643:,
639:,
635:,
631:,
627:,
623:,
615:,
611:,
607:,
599:,
595:,
591:,
587:,
583:,
579:,
47:.
3135:)
2321:e
2314:t
2307:v
1387:e
1380:t
1373:v
1332:.
1264:.
1181:.
925:)
919:(
914:)
910:(
906:.
892:.
481:6
465:1
462:5
444:4
426:3
410:1
407:2
389:1
289:B
285:A
281:B
277:B
273:A
269:A
261:B
159:)
153:(
148:)
144:(
134:·
127:·
120:·
113:·
86:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
