Telephone plug

A telephone plug is a type of male connector used to connect a telephone to the telephone wiring in a home or business, and in turn to a local telephone network. It is inserted into its female counterpart, a telephone "jack", commonly fixed to a wall or baseboard. The standard for telephone plugs varies from country to country, though the RJ11 "modular connector" has become by far the most common.

A connection standard, such as "RJ11", specifies not only the physical connector, but how it is wired (the "pinout"). Modular connectors are specified for the Registered Jack series of connectors, as well as for Ethernet and other connectors, such as 4P4C (4 position, 4 contacts) modular connectors, the de facto standard on handset cables, often improperly referred to as "RJ connectors".

Contents 1 History 2 List of connections 3 Wiring 4 Compatibility 5 List of plugs 5.1 Modular connectors 5.2 Other connectors 5.3 International standards 5.4 National standards 5.5 Legacy 6 List of countries and territories, with the plugs they use 7 See also 8 External links

History

Historically the telephone was often owned by the supplier and permanently wired in to the telephone line they supplied but as phone markets became more deregulated there was a need for a simple plug-in interface that consumers could use. Many countries initially used their own connectors. For example Bell System companies in the 1960s used a round plug about 40mm in diameter with four prongs about 15mm apart. National connectors remain in service but few are used for new installations.

List of connections

On a conventional wired telephone, there are 4 connections, each of which may be hardwired, but more often uses a plug and socket:

telephone line to phone cable

The wall jack. This connection is the most standardized, and often regulated as the boundary between an individual's telephone and the phone network.

phone cable to phone base

This and further connections is generally not regulated, but instead has de facto standards. It is often 6P4C, which is often RJ11, but may be proprietary or hardwired.

phone base to handset cable

handset cable to handset

The last two (the handset cable) has a de facto standard of a 4P4C connector with straight through cable.

Some of these may be absent:

• Wired telephones may not have a separate base and handset,
• the defining characteristic of wireless telephones is that they do not have a handset cable, and
• the defining characteristic of mobile telephones is that they do not have a phone cable.

Wiring

A standard specifies both a physical connector and how it is wired. Sometimes the same connector is used by different countries but wired in different ways.

For example, telephone cables in the UK typically have a BS 6312 (UK standard) plug at the wall end and a 6P4C or 6P2C modular connector 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 straight through cable 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 crossover cable).

When modular connectors are used, the "latch release" of the connector should be on the "ridge" side of flat phone wire in order to maintain polarity.

Compatibility

Different telephone connections are generally compatible with the use of an adapter: the physical connector and its wiring is the primary incompatibility.

See: gallery of telephone adapters.

List of plugs

This list is incomplete; you can help by expanding it.

Modular connectors

• 4P4C and 4P2C for handset cables (often erroneously referred to as RJ9, RJ10, and RJ22)
• 6P2C for RJ11 single telephone line
• 6P4C for RJ14 two telephone lines
• 6P6C for RJ25 three telephone lines
• 8P8C for RJ61X four telephone lines, RJ48S and RJ48C for four-wire data lines, RJ31X single telephone line with equipment disconnect, RJ38X (similar to RJ31X but with continuity circuit)

Other connectors

• 50-pin miniature ribbon connector for RJ21X, used for up to 25 lines for multiline phones such as the ITT 2564, key telephone systems such as the 1A2 Key System, and PBX systems.

International standards

• RJ11, by far the most common
• BS 6312, British
• F-010, French
• TAE connector, German

National standards

• TDO-connector, Austria
• WT-4, Polish National Standard

WT-4 and RJ11 telephone socket (double system)

WT-4 telephone plug with RJ11 outlet (adapter)

1. WT-4
2. RJ11
3. Cable holes

Traditionally, the 5th plastic pin disconnects 1 μF capacitor that shorts telephone line while plug is not inserted into socket. In modern makes it does nothing electrical, and capacitor compartment was reused for additional RJ11 socket.

Legacy

• 600 series connector, Australia
• Protea, South Africa
• SS 455 15 50, Sweden and Iceland
• Telebrás plug, Brazil
• Tripolar plug, Italy

List of countries and territories, with the plugs they use

This list is incomplete; you can help by expanding it.

This list covers only single line telephone plugs commonly used in homes and other small installations. Special telephone sets use a variety of special plugs, for example micro ribbon for key telephone systems and the wide array of registered jacks.

Place	Plug or Plugs
Albania	RJ11
Algeria	F-010
Argentina	RJ11
Australia	610 or RJ11
Austria	TDO
Barbados	RJ11
Belarus	RJ11 or Polish national 5-pin (WT-4) in older installations
Belgium	Tetrapolar or RJ11
Bolivia	RJ11
Bosnia	RJ11, or older 3-pin plug used in countries of former Yugoslavia
Botswana	BS 6312
Brazil	Telebrás plug or RJ11
Bulgaria	RJ11 or Russian/Polish 5-pin plug in old installations
Canada	RJ11
Cayman Islands	RJ11
Chile	RJ11
China Mainland	RJ11
Colombia	RJ11 Also in use the national standard [1]
Costa Rica	RJ11
Croatia	RJ11, or older 3-pin plug used in countries of former Yugoslavia
Cyprus	BS 6312 (431A and 631A) With RJ11 used for ADSL
Czech Republic	RJ11, or older 4-pin national plug
Denmark	RJ11 in newer installations, but mainly the national 3-prong standard. [2]
Dominican Republic	RJ11
Ecuador	RJ11
Estonia	RJ11 or Polish national 5-pin (WT-4) in older installations
Faroe Islands	RJ11
Finland	RJ11, 3-prong national standard in older installations [3]
France	F-010
Germany	TAE, or 8P8C (RJ-45) for ISDN
Gibraltar	BS 6312
Greece	RJ11 although other types can also be found
Hong Kong	RJ11 in newer installations, or BS 6312
Hungary	RJ11
Iceland	RJ11, or SS 455 15 50 in older installations
India	RJ11
Indonesia	RJ11
Iran	RJ11, older installations may be CEI 23-16/VII or CEE 7/16.
Ireland	RJ11, 8P8C (RJ-45) for ISDN, Digital PBX and office systems (4 way post office jack on pre mid-1980's installations)
Israel	BS 6312 or RJ11
Italy	Tripolar plug or RJ11
Japan	RJ11
Latvia	RJ11 or Polish national 5-pin (WT-4) in older installations
Lithuania	RJ11 or Polish national 5-pin (WT-4) in older installations
Liechtenstein	Reichle-connector (4-pin Swiss telephone plugs in old installations)
Luxembourg	RJ11 (sometimes older 4-pin luxembourgish telephone plug can be found)
Macedonia	RJ11, or older 3-pin plug used in countries of former Yugoslavia
Malaysia	RJ11
Malta	BS 6312, or RJ11 in some newer installations
Mexico	RJ11
Montenegro	RJ11, or older 3-pin plug used in countries of former Yugoslavia
Morocco	F-010 or RJ11
Netherlands	RJ11 and the Dutch telephone plug
New Zealand	BS 6312
Norway	8P8C (RJ-45) in newer installations (same plug for POTS, ISDN and LAN), 3-prong national standard in older installations [4]6-prong national standard for local battery telephones. (Not used since approx 1980)
Pakistan	RJ11
Panama	RJ11
Peru	RJ11
Philippines	RJ11
Poland	RJ11 or Polish national 5-pin (WT-4) coupled with RJ11 socket in older installations
Portugal	RJ11 (also known as R.I.T.A.)
Romania	RJ11, 3-pin triangular plug or 5-pin circular plug
Russia	RJ11, or Polish national 5-pin (WT-4) in older installations
Serbia	RJ11, or older 3-pin plug used in countries of former Yugoslavia
Singapore	RJ11
Slovenia	RJ11, or older 3-pin plug used in countries of former Yugoslavia
Slovakia	RJ11, or older 4-pin national plug
South Africa	RJ11 or Protea, 8P8C (RJ-45) used for ISDN
South Korea	standard 4-pin plug, or RJ11 for special use
Spain	RJ11
Sri Lanka	RJ11
Sweden	SS 455 15 50 or RJ11
Switzerland	Reichle-connector or older 4-pin plugs
Taiwan	RJ11
Thailand	RJ11
Turkey	RJ11
United Arab Emirates	BS 6312
United Kingdom	BS 6312 (431A and 631A) With RJ11 used for ADSL British Telephone Sockets
United States	RJ11 and other Registered jacks, 4-pin Bell System plugs in older installations
Venezuela	RJ11
Zimbabwe	BS 6312 or RJ11

See also

• Power plugs/sockets by country
• Network interface device

External links

Wikimedia Commons has media related to: Telephone adaptor

• Telephone plug list — at Steve Kropla's World Wide Phone Guide
• How to install telephone wiring