in answer to a couple of people who mailed me off line - ak = aknowledgement, for those of us who can't spell. I should have used the term "ack" The point I was trying to get to is that perhaps the timeout values were too small, and the latency of the satellite link sometimes crossed that threshold, thus screwing up the tunnel, and triggering renegotiation, which in turn adversely effected throughput. I don't think the guy who posted the original question ever did answer as to how he determined his throughput - using ping or file transfer.
as for the relevance of MTU, I've run across this in my testing. In particular, a VPN used to tunnel IPX. I discovered that packet sizes of 1500 failed, whereas packet sizes of 1492 worked just fine. I don't recall where the cutoff was. It may even have been 1498. So yes MTU can be an issue. ""Yahoudi"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > after some recent bad experiences with VPN across DSL, I began to wonder > about MTU sizes and their effect, particularly when coupled with off the > wall links or protocols. > > OTOH, it could be that your VPN boxes don't like the latency across the sat > links. maybe you have your ak timeouts set too low, and the boxes are > spending all their time renegotiating links rather than sending data? > > BTW, how are you measuring speeds? Ping tests? File transfers? > > > ""Jerry Deer"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > To make our vpn connection work the satellite/isp provider had to open > > certain ports to make our vpn connections work in the first place . does > > anyone have any ideas as to what they may have blocked or not configured > > correctly to make the connection so unbearable slow? I know our watchgaurd > > sohos will bring connection speed down some but we have 128k vpns that are > > running a lot faster then this satellite connection and as i mentioned > > before the satellite connection shows connections speeds of avg 700k > before > > adding the vpn units. > > Thanks for ANY help, > > Jerry > > > > > > > > > > > Hello All , I am having problems running over a " fast " satellite > > > connection. I do a speed test from the pc hooked to the satellite > > equipment > > > and the actual satellite connection is getting average 700k BUT as soon > as > > a > > > slap on the ol watchgaurd vpn solution it and hook a computer to that > the > > > speed drops to below a 56k I know this is not a cisco problem but > > watchgaurd > > > support is very lacking in my humble opinion and was hoping someone may > > have > > > had simular experience and could point me in right direction. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=38185&t=38080 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
