Full Duplex or Half Duplex ???

[nguyenminhtung]

I have Linksys NIC at home connect to cable modem. When I enable the NIC to be Full-Duplex, my cable speed improves 10 kbps more. But I read that somebody else had it the opposite (Half-Duplex instead of Full-Duplex) and their connection improved. So what the different? When should we enable Full-Duplex and when should we not? Consider a NIC that can support both Half and Full-Duplex.

Thanks.

 

[L3Guy]

nguyenminhtung;

The key to duplex issues is to have both ends of a link the same.
If one end is in half duplex mode and the other is in full, late collisions
and other ugliness will occur. The full duplex side sees on problem in transmitting and receiving at the same time. However, the half duplex connection will stop and re-transmit
if it receives data while its transmitting. And if more than 64 bytes are transmitted, the
nic may not be able to re-transmit correctly.

How do you tell if you use full or half duplex?
Rules of thumb.
"All" hubs are half duplex. everything that is connected to the hub must auto-sense to half.
All 10/100 cards will do half or full duplex.
all switches are full and half duplex. Each port may be set differently.
Older 10Mb nic's are half duplex only.

Cable modems, you ask. I fear its Read the manual time.

Hope this helps;

Doug

The full duplex hubs were buffered gigabit "hubs" that IMHO were simply very lame switches.

 

[UWDawg]

Would it be better to leave the nic on auto sense mode?

 

[nguyenminhtung]

L3Guy, thanks alot!