[Asterisk-Dev] Uncommon callback

[SteveK]

On May 22, 2005, at 1:45 PM, Paul wrote:
>>
>> Normally you'd have system #1 forward the call to system #2 itself
>> rather than having system #2 call back to #1. It sounds like you're
>> trying to work around the fact that system #2 is behind some kind  
>> of NAT
>> or stupid firewalling.
>> If that's the case, you'd do better just to fix that problem at  
>> source
>> rather than inventing complicated way of working around it. Or if you
>> really can't fix it, put up a VPN tunnel between the two machines to
>> bypass the firewalling.
>>
> I use port forwarding over SSH a lot. It's a lot easier than  
> modifying routers and firewalls. There are also things like PPP  
> over SSH. I googled up a few helpful pages on that one and am going  
> to try it out soon for something I want to do.
>
> To use either of the above for SIP or IAX transport I would do some  
> bandwidth testing untunneled and tunneled. I remember seeing some  
> comparison charts for vpn methods with bandwidth and latency  
> measurements. IIRC - it seemed to indicate some mathods would  
> really suck for voip.
>

You can't tunnel IAX over ssh, because ssh port forwarding is UDP  
only.  And you don't really want to tunnel VoIP at all over TCP if  
you can avoid it, because if you drop a couple of packets, you end up  
with a lot of latency.  Same goes for PPP over SSH, for the same reason.


-SteveK