svn+ssh with custom port number and public key authentication

To make custom configurations for svn+ssh:

Edit ~/.subversion/config

- add the ssh configuration details under [tunnels]
like:
foobar = /usr/bin/ssh -i /home/foo/.ssh/foobar.private -p 12345

Now use:
svn co svn+foobar://user@svn.test.com/home/test/repos/foobar