Another option is to establish a single SSH session using port mapping and then run all of your SVN traffic across that.
Something like ssh -L 3690:svn_server:3690 ssh_server svn svn://localhost/.... The first line says take any traffic destined for the svn port on my machine and send it to the svn port on the svn server at the other end of an SSH tunnel. The second line says pretend my svn server is local JLm
