Sony DT310 User Manual

Least Cost Routing (LCR) automatically selects the cheapest
way to establish the connection to the desired external
number. Please ask your system administrator if this function
is installed in your system.

If the extension has been configured to use LCR, each 
external call will be analysed and the cheapest way will be 
selected.

Dial the digit(s) for external call access and the
external number
The usual way of making an outgoing external call.

If LCR has been installed in your system, but your extension
is not configured to use it automatically, you also have the
opportunity to get the cheapest connection by dialling the
LCR code before you dial an external number.

Dial the LCR code
Please ask your system administrator for the LCR code.