Firewall Blocking Voice Communication

[mainstream]

I am behind the firewalll imposed by the ISP that is blocking all voice communication. How do I solve this problem without having the firewall removed.

[md_27514]

You have 3 options:
1) change the ISP for more reasonable one
2) find out what ports are blocked, there are provides working on some nonstandard ports that might be left open. Or if you have a friend outside the firewall running asterisk, ask him to register you on his system using any port left open
3) punch through using VPN. This also requires a machine outside...

[mainstream]

My ISP has installed a firewall on their Internet Service that has as one result the blocking of Voice communication. Ports are being blocked as a result and their is a need to find a method either of going around or through the firewall. The option of securing the removal does not exist. Is there software that will assist in this regard?

[mberlant]

Ad md 27514 said, you can't figure a workaround until you know what you are working around. What specific ports are being blocked by your ISP?

[mainstream]

The ports that are being blocked by our ISP provider are, 5711, 5723, 5060,5061, 5062 and 5063.

[ctylor]

That's pretty harsh, to block all the standard SIP ports. I wonder how they get away with that.

So what happens if you change your SIP device to other ports that are not being blocked? If you run this port testing program (found here http://www.voipuser.org/port_forward_tester.html ) with your software and router firewalls disabled temporarily, you can quickly see what local ports are able to receive internet traffic. Then change your SIP device SIP and RTP ports (if necessary) to something that program reports as a green, open port. Unless your ISP also uses traffic shaping to throttle SIP into oblivion, this should work. I use a Canadian ISP, Shaw, that has no problems (apparently) with third-party VOIP traffic, but that throttles unencrypted Bit torrent traffic into the stone age. Consequently the only way to avoid that here is to use the new Azureus with encryption enabled, which nicely dodges the traffic shaping. If your VOIP also suffers from that, then you might have to look into setting up a VPN (many for-pay sites offering that on the net), in addition to using non-standard ports.