The SMS module for asterisk was developed by Adrian Kennard, and is an implementation of the ETSI specification for landline SMS, ETSI ES 201 912, which is available from www.etsi.org. Landline SMS is starting to be available in various parts of Europe, and is available from BT in the UK. However, asterisk would allow gateways to be created in other locations such as the US, and use of SMS capable phones such as the Magic Messenger. SMS works using analogue or ISDN lines.