Hi Jim, > How many other systypes support path mtu? If I put code in to use this on > OpenBSD, how many other arch maintainers would be willing to add the > necessary code and do the testing for it to work on your systype?
I do not know if it is worth to do. Today rx sends typically packets that are 4*MTU which evaluates mostly to something around 6000 bytes. Noone has been able to explain why _four_ (and not five or three) times MTU size. I would appreciate if the code would not send fragments at all as you loose big on lossy links and gain almost nothing on today's CPUs. I do not know why fragmenting in the IP layer is cheaper that in the rx layer, but on a 40Mhz SPARC, it is muchfaster. On an 800Mhz PC it is not. I do not think we should make design descicions that care about 40Mhz SPARCs any more. Suggestion: Om systypes with easy MTU discovery support, do the discovery and then send packets that fit that size. On systypes without, either look at the interface or just guess 1500. > If I do this, is it useful? I'm not even sure what pp->ifMTU is used for. > It does not seem to limit the size of udp packets sent. Maybe it's not used > for anything. I think packet sent is RX_NUM_FRAGS * pp->ifMTU, but the MTU code is very mangled together with the mumbo-jumbo packet code, so I doubt either can be sanitized alone. I frequently think that I'm brave and look at the rx code again and then it comes back to me why I gave up in the first place ;-] Harald. _______________________________________________ OpenAFS-devel mailing list [EMAIL PROTECTED] https://lists.openafs.org/mailman/listinfo/openafs-devel
