I have heard of the "TCP over TCP" issue but have not had any bad experiences so far. I am currently using both TCP and UDP-based VPN systems and while the TCP-based one is a bit slower, it still seems very stable for applications such as Terminal Services, FTP, http(s), etc.
I do notice problems with some apps (FTP for example) if I'm trying to use a TCP-based connection over a satellite link - lot of TCP RSTs and "Zero Window"-type errors in the sniff though on some satellite systems even UDP-based tunnels don't seem to work very well for anything other than low bandwidth applications. Thanks again...Nd On Sat, 18 Aug 2007 11:52:46 -0400 Michael_google gmail_Gersten <[EMAIL PROTECTED]> wrote: >On 8/18/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: >> I have several options - what's the issue w/ using TCP? > >TCP over TCP has some problems, the least/biggest of which is the >timeout factor. > >If there is a communication problem, TCP has a "back off and >resend" >rule. This starts with "I didn't get an acknowledgment. I might be >sending data too fast, or data might have gotten lost. I'll pause >for >two seconds, and then send the data again". > >The problem? If the low level TCP stream does this, then any >higher >level stream with data in transit will also see a delay, and a >need to >re-transmit. > >I may be doing a horrible job of explaining the problem. A simple >terminal session may have no problem -- a single packet of data >will >eventually get an acknowledgment back. > >But if there is a stream with more and more data behind it, then >you >wind up with an ever increasing resending that never gets caught >up. >Eventually all the TCP channels break. > >TCP was designed with certain assumptions in mind. It does not >work as >a general purpose transport -- that was never it's goal. > >IP over IP works. >UDP over UDP works if your UDP protocol supports it. >TCP over TCP fails. The timeout rules cannot stack properly. -- Make up to $100/hour by getting a Sports Medicine Degree. Click Now! http://tagline.hushmail.com/fc/Ioyw6h4fRPYLey2rvkF1ZXnAAaXHzBNMdDrODhnZzfDccOe6VWXOUx/