On Tuesday 09 April 2002 3:00 pm, Zygo Blaxell wrote: > TCP *relies* on packet loss and predictable latency in order to optimize > itself for available bandwidth, and TCP running on top of another TCP > will defeat the algorithms TCP uses. Your PPP over SSH link *will* > get slower and slower until it crashes every time you try to use it to > move any non-trivial amount of data. Even IP-over-HTTP (i.e. one HTTP > 1.1 request per packet, with keepalives and a very short timeout) is > better than PPP-over-SSH.
The reason I discovered PPP-over-SSH was that I was working inside a network where the only ways out to the outside world were: a) through the mail server by SMTP b) via a proxy HTTP/FTP server c) using Socksified SSH ...and I wanted to use other protocols which were blocked (eg ICMP & POP3). Therefore IPsec and CIPE were not an option, but I've easily had the PPP-over-SSH link up for days at a time (it's a fat corporate pipe of unknown bandwidth at one end, and a 128kbps up/ 512kbps down cable modem link at the other), and I've readily transferred 600Mb ISO images of CDs across it for when I've needed to install some software... If TCP-over-TCP is as bad as you say, maybe I should have set up IPsec and tunneled ESP through SSH, but that idea just seemed silly..... :-) Antony
