At 11:03 AM 6/1/99 -0700, you wrote:
>
>> 
>> If your nic driver chains packets (such that there is no time in between)
>> you will see good throughput from the box but your overall network
>> performance will suffer. A PCI card with continueous traffic can completely
>> hog your lan (particularly at 10Mb/s)...which can cause a lot more
>> collisions on your network as other devices will not have access until the
>> hog is finished sending. For "Fairness" gaps in between frames are better
>> as you approach capacity of your wire. 
>> 
>> Dennis
>
>
>       the interframce gap will allow other hosts to contend for the
>wire.  the ethernet capture effect decreases as the number of hosts on
>the segment increases.  the interpacket gap is 9.6uS (or 96 bit
>times).  an ethernet card listens to the wire before
>transmitting  a card that is not able to transmit because the wire is
>busy will begin transmitting as soon as the wire goes quiet.  the max
>length of an ethernet is 46 bit times.  so a waiting card will alaways
>get first crack at the wire.  capture effect is due to stations
>colliding in trying to access the wire.  those that dont collide, are
>immune to the capture effect and get the wire first.

and if you have 2 cards waiting? or 3? or 10? Im not sure why, but with
certain PCI drivers there are a lot more collisions. 

Dennis



To Unsubscribe: send mail to majord...@freebsd.org
with "unsubscribe freebsd-hackers" in the body of the message

Reply via email to