> 3. One of the things that the TCP IP folks want us to do on the hardware side > is to increase the maximum frame size to 64k. for this hipersocket. > > 4. This would normally increase the MTU size to 56k for the hipersocket. > > 5. If I remember properly the 56k value would exceed the SAP recommended > MTU size of 8k.
That recommendation is for garden-variety Ethernet where 8K jumbo frames are the max supported. Hipersockets != Ethernet. 56K MTU works nicely. > 6. The IBM z/os TCP/IP support says that the MTU size could be forced to 8k. > Anyone have any experience in forcing an MTU to 8k like this? Any > unwelcome side effects? It's going to increase the CPU utilization of the TCP stacks substantially since the stack has to do more fragmentation/reassembly. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
