Panasonic EB-X300 - Manual (Page 122)

Glossary of Terms 119
SDN Service Dialling Number. This number enables you to access
special services provided by your network operator, such as
customer support, emergency services, etc.
Service Provider The organisation responsible for providing access to the GSM/
GPRS network.
SIM Subscriber Identity Module. A small smart-card which stores unique
subscriber and user-entered information such as Contacts entries
and SMS messages. Supplied by your service provider.
SMS Short Message Service. A basic mail system used for cellular
phones. This service allows sending/receiving of short text
messages.
WAP Wireless Application Protocol. The communication standard which
enables you to download resources from the Internet to your phone.