A whole VoIP solution

In general, the ISP can block the TCP 1720 port only, try to :

1. If both VOIP Gateway in two endpoint support modifying the H.225 Q.931 TCP port ( like change to 1721 ), change them;

2. Most VOIP Gateway can’t modify the TCP port of Q.931, try to use some Port Mapping software like :
PortTunnel http://www.steelbytes.com
GDataPipe http://www.gwacc.co.za/software.htm
PortMapper http://www.analogx.com

So it should works like :

VOIP—1720—PortMappingComputer—1721—–Internet—–1721—PortMappingComputer—1720—VOIP

Good luck.

ahmed you can do it with gateways at either end depending on the kit your using. if you want to discuss let me know!

The only backbone for internet in kenya is Jambo net but for reasons unknown they have blocked VoIp thus i cannot get connection to net2phone servers please can someone advice me how i can go over it, thanks Mohammed