Other Connectors Used in Sweden
In addition to the standard Swedish plugs and sockets, RJ11 connectors are quite common, especially in offices. Even 8P8C modular telephone sockets can be found. Most telephone equipment sold in Sweden today has RJ11 sockets and corresponding cables with 6P4C plugs on each end and an adaptor from RJ11 to SS 455 15 50 sockets. The Swedish practice with sockets connected in cascade can be maintained with RJ plugs and sockets by using the first pair for connecting the terminal equipment to the PSTN and the second pair for the connection of a line towards the next socket. However, the presence function found in Swedish Standard sockets is lost, so disconnecting a telephone from its socket requires replacing it with a dummy plug so the sockets further down in the chain will remain connected.
6P6C modular plugs are also used for telephony, but only for certain telephone exchange systems - never for direct connection to the PSTN. ISDN telephones and outlets always have 8P8C modular connectors.
Read more about this topic: Swedish Telephone Plugs & Sockets