, , , , . , , ( ).
: , . . . . . (switches) . . , . : , , , .
. , , , . , , .
(virtual) . , . , . , , . . . (), , ().
.
1. .
, .
Power line, , , .
Cable, , (10/) (40 /).
Radio, 50 .
2. .
Fax, .
Voice mail, ( ), .
Voice, .
V.34, V.90, .
3. .
Win (US Robotics) (), , .
HDSL (High-bit-rate Digital Subscriber Line) ( V.90-), 56 .