| 摘要 |
<p>A telephone monitoring and route selecting device is disclosed which, in use, sits between the telephone and the telephone line and monitors dialling signals generated by the telephone and attaches appropriate prefix numbers to the dialled number in order to route the call via a desired telephone service provider. The router device does not require any electromagnetic relays or optocouplers to isolate parts of the system and can be made solely from solid state components.</p> |
