VoIP firewall Traversal Options

I am working on a solution for firewall travers开发者_开发百科al of VoIP calls.

Anyonw who has tried this things... What are the options for going about this??

I hav tried with OpenMCU, but that doesn't work!

Anyone with a tried solution for firewall traversal?

Since you mention OpenMCU, I assume you are talking about VoIP calls using the H.323 protocol.

You basically have 2 options

• use the firewall traversal protocol designed for H.323 (H.460.18 and H.460.19)
• let your firewall proxy the call

You can't use any generic firewall traversal methode like ICE or STUN, since H.323 embedds addresses inside the packets wich must be rewritten.

For H.460.18/.19 you need support for this protocoll in both your endpoints and you gatekeeper, eg. use the GNU Gatekeeper.

To proxy the call, your firewall must support this natively or you can run The GNU Gatekeeper on the firewall.

• ICE (libnice)
• TURN
• STUN
• UPnP

It depends what you mean on "firewall traversal". The technologies mentioned by jesup is more about establishing a p2p media path then about firewall.

VoIP works fine trough firewalls if one side is on public IP (for example server routing the media).

The problem is if you wish to establish direct media paths between two devices when both of them are behind NAT’s, without server media relay. For this you can use ICE/STUN/TURN/UPNP.

However if you have problems with firewalls not allowing UDP traffic, then you have to tunnel the traffic somehow. There are many solutions for this. The worst is by a VPN. Better if you use some VoIP aware tunnel (VoIP tunneling and encryption, VoIP over TCP/HTTP and other similar software).