switchport 1gig to output port at 100meg

carl_townshend · ‎06-15-2009

Hi all, if I have a server plugged into a port, that is 1 gig, and a pc plugged into the same switch at 100 meg,if the server is pushing traffig to the host faster than the 100 megabit port can handle, what will happen, and what normally happens? does tcp slow it down ?

Joseph W. Doherty · ‎06-15-2009

Normally a port will queue/buffer packets/frames awaiting transmission. If arrival rate continues to exceed transmission rate, queue/buffer overflow drops packets/frames.

Faster port to slow port is "classic" (your) example, but so too is multlple ports sending to fewer ports (e.g. 24 100 Mbps ports sending to gig port).

"does tcp slow it down ?"

Simple answer is yes, but there's much to TCP. Suggest you search Internet for additional information about TCP behavior. Your might start here: http://en.wikipedia.org/wiki/TCP_congestion_avoidance_algorithm