[Asterisk-Users] IP to IP call without server?

[Jim Van Meggelen]

asterisk-users-bounces at lists.digium.com wrote:
> Hi.
> I'm really new.
> I was just wondering if it is possible at all to do a IP to IP call
> without a * server (or as a matter of fact, any other kind of server)?
> say I'm at mydomain.com's 10.0.0.1 and I want to call my buddy at
> hisdomain.com's 192.168.0.3. Is this sort of things possible?
> Or must we
> all both be registered with the same server to do that? Can
> this not be
> done without passing thru server (*)?
> Thanks.

The answer is both Yes and No:

~~ Yes: ~~

If the two IP endpoints can connect to each other, and the protocols are
compatible, peer-to-peer VoIP connections are totally feasable.

Technically speaking, most VoIP protocols are peer-to-peer; as long as
both ends are using the same protocol, any call can ultimately be a
direct connection between endpoints. If you can configure the dialplan
in your terminal (IP phone or soft client) to know exactly the IP
address of the destination endpoint (your buddy's IP phone or soft
client), and the destination endpoint is willing to accept incoming
connections from your client, you're good to go. Getting this going
across networks is usually a bit more complicated that that.

~~ No: ~~

Being "really new", you'd avoid a ton of frustration for yourself (not
to mention a steep learning curve) if you interface through some sort of
registration server. Why create needless hassle for yourself?

When you start adding firewalls, NATs, DHCP, mobility and a bunch of
other things, it becomes attractive to centralize these configurations
in a machine that provides lookup services to all users. It's not
*needed*, but it is very beneficial. 

Ultimately, the complexity of the network is such that it will become a
necessity. For example, the internet works fine without DNS (some apps
do not, but I digress), but without it, everyone would need to keep
track of IP addresses. DNS has become essential. Similarly, there is no
technical reason to have Google, but can you imagine surfing without it?

If you want to use VoIP without getting into Asterisk, services such as
FreeWorldDialup are worth looking into. 

Cheers,

Jim.