Conference 7.286::fddi

872.0. "Ultrix FDDI performance." by ROMTSS::CERIOLI () Wed Feb 24 1993 11:52

Hi there,

	I have 2 DecSystem 5900 connected thru FDDI and Ethernet.
	I observe almost the same througput doing ftp over the ethernet
	network and over the fddi network.

	I've tried sending ICMP pachets of various sizes and i got a
	roundtrip time of 3. ms for 64 byte packets, 0. ms (much better)
	for 1024 byte packets, and again 3. ms for > 1200 byte packets.

	I've read somewhere about a buffer size problem, and that should
	be possible to fix the problem modifying the MTU on the fddi to
	a value that is a sub-multiple of 8192 (4096 should be appropriate
	for fddi).

	Unfortunately I have no idea on how to do that, and moreover I'm not
	sure that this would fix the problem.

	Any help would be greatly appreciated.

	Andrea.