On Fri, Apr 27, 2001 at 12:47:09PM -0700, Tony Hain wrote:
I understand all those points; I was reacting to the comment that the only jumbo frames were between the routers, so the only ones coming in would be 1500. Look at John's notes from 4/25 8:10pm & 4/26 9:40am. There is no way I know of for a larger frame by itself to increase the speed of a packet. What was missing was the subsequent comment about tunneling those packets (thus increasing the size beyond 1500) across the GE links to the distribution router. Avoiding fragmentation clearly has performance gains, but fragmentation is unnecessary if the packet size remains the same from end to end. The original scenario was simply standard-size feeders into a router, with jumbo frame GE between the core routers, then standard-size distribution on the other end. The claim was that jumbo frames in the middle made it go faster. If this is true I want to know how.
It is also possible that he has packets entering and leaving his network by SONET, ATM, FDDI, or anything else which is not Ethernet. By supporting jumbo frames on his GigE router links, he is potentially providing a path with larger MTU support. -- Richard A Steenbergen <ras@e-gerbil.net> http://www.e-gerbil.net/ras PGP Key ID: 0x138EA177 (67 29 D7 BC E8 18 3E DA B2 46 B3 D8 14 36 FE B6)