Hama DSL Router Connection Cable TAE-F to RJ45 6 m TAE-F to 8p2c Western Plug Telephone Cable for Connecting Modem/Router to Telephone Sockets TAE Connection Cable Suitable for DSL/ADSL/VDSL White: Amazon.co.uk: Electronics
A Complete Guide to Telephone Cable
British telephone socket - Wikipedia
Canon Knowledge Base - Types of Cables and Their Connectors