On Apr 13, 2007, at 4:55 PM, Fred Baker wrote:
The biggest value in real practice is IMHO that the end systems
deal with a lower interrupt rate when moving the same amount of
data. That said, some who are asking about larger MTUs are asking
for values so large that CRC schemes lose their value in error
detection, and they find themselves looking at higher layer FEC
technologies to make up for the issue. Given that there is an
equipment cost related to larger MTUs, I believe that there is such
a thing as an MTU that is impractical.
1500 byte MTUs in fact work. I'm all for 9K MTUs, and would
recommend them. I don't see the point of 65K MTUs.
Keep in mind that a 9KB MTU still reduces the Ethernet CRC
effectiveness by a fair amount. Adoption of CRC32c by SCTP and iSCSI
has a larger Hamming distance restoring the detection rates for Jumbo
packets.
-Doug