[plug] VOIP suggestions please

Brad Campbell brad at wasp.net.au
Thu Apr 6 23:25:10 WST 2006


G'day all,

I'm making my 1st steps into the wonderful world of VOIP.
I need a secure channel from wherever I may be on the planet back to home base in Perth.

What I have atm is a wonderfully working openvpn setup where I have a machine tucked away in the 
corner in Aus that has an openvpn tunnel back to my machine in dxb.

I've tried playing with SJPhone and doing local lan type calls.. all groovy..
My issue is the network down there is 192.168.0.0/24 and my openvpn network is 10.8.0.0/24.

I *thought* (wrongly it would appear) that I could just add some iptables dnat rules on the box down 
there to forward some ports from the 192.168.0.0/24 interface across my vpn and I'd have noise..

However, showing my complete ignorance in all things VOIP it was not to be.
Are there any linux/windows voip clients that just work on a single port? or can be restricted to a 
smaller range of ports for the RTP connection? Failing that.. any good advice on a small proxy that 
might run on the box in Perth for h323 or sip and perhaps a link for a good howto site?

Everything I've read thus far has really just confused me further. all I want to do is make a call 
from 10.8.0.10 to a windows machine on the lan down there on the 192.168.0.0/24 subnet.
I don't have control over the routes on the windows boxes, so I can't tell them how to get to the 
10.8.0.0/24 subnet.. I really need to make the local interface look like it's the one making the 
call I guess.


While I'm on the line... heres a groovy tip I stumbled over while needing to do a remote knoppix 
install behind a NAT device I could not punch a hole through driven by someone who needed extreme 
hand holding..

use a reverse port map in ssh..

put knoppix disk in drive
type knoppix 2 at bootprompt
type passwd
enter new password "password" twice
type /etc/init.d/ssh start
type ssh -R 2224:*:22 brad at myhosthere.com
when it asks about unknown host type "yes"
type the password

then from my machine...
ssh -p 2224 localhost

Boom.. I'm in :)

Do that with a windows install CD!

Brad (hugging his knoppix disk)
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams
	



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