[nsp] Frame bursting

Pete Kruckenberg pete at kruckenberg.com
Mon Mar 31 10:18:32 EST 2003


On Mon, 31 Mar 2003, Charles Spurgeon wrote:

>  >The Gigabit 802.3z standard provided for "frame bursting",
>  >which allows GigE transmitters to send a burst of frames
>  >without waiting for the normally-required 9.6 microsecond
>  >interframe gap.
>  >
>  >Does Cisco support this on GigE interfaces? Do most vendors 
>  >support it, or not? What are real-world experiences with 
>  >using frame bursting?
> 
> AFAICT, no vendor has ever built half-duplex GigE equipment.  All
> vendors provide full-duplex GigE only, and normal inter-frame gaps are
> used between frames on full-duplex links. There is no channel
> contention in full-duplex oepration, and therefore no need for frame
> bursting to improve channel efficiency.

So, if I understand correctly, a normal (12-byte)  
inter-frame gap isn't necessarily going to have a huge
impact, even on 1500-byte frames. Going to jumbo frames
won't make a noticeable difference (0.8% efficiency loss vs
0.1% efficiency loss).

In a full-duplex environment, IFG isn't a big issue?

Pete.




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