Using Jumbo framing
Using jumbo framing can improve performance but if not implemented
correctly you can quickly go from poor performance to worse. You first
need to make sure the NIC driver supports using jumbo framing. And when
deploying you must make sure all devices on the layer 2 side of the
network are using jumbo frames otherwise without hitting a layer 3
router which would produce a ICMP need to fragment but DF bit was set
message as part of max path discovery you will get very poor performance
from that segment of the network.
Smaller frames usually mean more CPU interrupts and more processing
overhead for a given data transfer size. Often the per-packet processing
overhead sets the limit of TCP performance in the LAN environment. The
above graph, from a white paper[2] by Alteon is an often cited study
showing an example where jumbo frames provided 50% more throughput with
50% less CPU load than 1500 byte frames.
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
[EMAIL PROTECTED]
Sent: Friday, October 19, 2007 7:49 AM
To: veritas-bu@mailman.eng.auburn.edu
Subject: [Veritas-bu] Jumbo Frames
I'm wondering if you can clear something up for me, how do people tend
to configure their 1GbE ports for jumbo frames.
We currently don't have a separate backup network. I don't really want
to create a separate backup network right now just to for jumbo frame
support although vlans might help with that.
What happens when non jumbo'ed (non netbackup) frames get sent to the
jumbo framed ports? From what i have been reading, your network speed
will be slower but how much?
Thanks,
Karl
image001.gif___
Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
