What is autonegotiation and how does it provide increased network bandwidth?
Answer
Autonegotiation allows a device to negotiate to the highest selected speed and duplex setting supported by both it and its link partner.
For example, assume you connect a CP220x with a Router.
The CP220x supports:
10 BaseT - Full Duplex 10 BaseT - Half Duplex
The Router supports:
100 BaseT - Full Duplex 100 BaseT - Half Duplex 10 BaseT - Full Duplex 10 BaseT - Half Duplex
After the two devices exchange their capabilities (i.e. autonegotiation), they will both decide that the fastest speed and duplex setting supported by both devices is '10 BaseT - Full Duplex'.
If autonegotiation is not supported, then both the CP220x and the router would default to the lowest bandwidth setting, '10 BaseT - Half Duplex', because they do not know each other's capabilities.
Autonegotiation