Date: Thu, 30 Nov 2000 22:08:32 +0100 From: Mark Rowlands <mark.rowlands@minmail.net> To: freebsd-questions@FreeBSD.ORG Cc: dkelly@HiWAAY.net Subject: Re: ftp transfer rates on my LAN Message-ID: <00113022083202.01128@web1.tninet.se> In-Reply-To: <3A269F04.3DEF4C32@urx.com> References: <B9FB8C769C17D411892D00B0D021653203F6D1@sf_pdc> <20001130103627.B22943@HiWAAY.net> <3A269F04.3DEF4C32@urx.com>
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On Thursday 30 November 2000 19:40, Kent Stewart wrote: > David Kelly wrote: > > On Thu, Nov 30, 2000 at 09:33:24AM -0500, bob@sfcei.com wrote: > > > Just my .02 here. IIRC, Windows seems to max out around 1472 for the > > > MTU, otherwise there are lots of collisions on the net. I set the MTU > > > on my FBSD box to 1472 and no collisions. This may affect your > > > throughput, if only marginally. > > > > Ethernet collisions are not bad. Don't sweat 'em until/if they reach > > 150% to 200%. A 1500 octet packat takes a while to send. But a"collision" > > happens in the first 64, takes very little wire time. Many NICs do not > > report these collisions at all. Don't believe I've seen them on 3com > > NICs I have used. Rather those NICs report *late* collisions which are > > bad, very bad, indicating a protocol implementation error, hardware > > failure, or a network which is too long. Yup, the network can get so > > big the speed of light is no longer fast enough to meet the ethernet > > timing specs. > > > > An analysis I no longer can find the URL for showed a 200% collision > > rate on 10 Mbps ethernet resulted in an 8% reduction in network > > capacity. So don't sweat the collisions. > > > > In this thread the user has two machines connected point-to-point with > > a crossed cable. No way for collisions to occur. There might be some > > advantage to turning on full duplex, which I've never seen > > auto-negotiated when connected that way, only when connected to a switch > > which does something to suggest to the machine that full duplex is > > available. > > I haven't measured what the affect is but Window's has a registry key > called TCPWindowSize on W2K that you can set to 16k and improve > throughput on files being sent to the Windows machine. I was told that > their receive windows size is setup to ack/nack records over dialup > and is really to small for real networks. I know where the key is on > W2K but not off of my head for the 9x variety. > > Kent from the horses mouth comes the following http://www.microsoft.com/windows95/downloads/contents/wuadmintools/s_wunetworkingtools/w95sockets2/default.asp the winsock2 patch includes:- Support for TCP large windows (TCPLW) and time stamps Support for selective acknowledgements Support for fast retransmission and recovery Support for DHCP release on shutdown Support for DHCP decline Support for per-adapter WINS servers Win95 is purportedly optimized towards dialup internet connectivity!!!! the following registry path supposedly fixes this. REGEDIT4 [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP] "DefaultRcvWindow"="64240" "DefaultTTL"="64" "PMTUDiscovery"=dword:00000001 "PMTUBlackHoleDetect"=dword:00000000 [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0000] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0001] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0002] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0003] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0004] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0005] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0006] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0007] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0008] "MaxMTU"="1500" [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans\0009] "MaxMTU"="1500" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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