hi does the length telephone cable going to router affect the speed?? and is there differnt quality cables??
The length can affect the quality,i think it is recommended that its not over 10 meters from the phone socket.
Not really, and at any rate; no matter how far from the router you are, it's better to have a wired connection, rather than a wireless one. The closer you are, the better, but it's not like a wire running from one room to another is going to cause speed drop.
anything over 300 feet is going to contribute to some signal loss. A big source of interference is when cables are run close to electrical lines or near florescent lighting.