A gatekeeper doe snot have dial peers as far as I know.
The only thing that the gatekeeper does is getting the registration of the gateways, and make a table with the I.P. address of the gateways and the phone numbers.
Like a DNS server, but for VOIP .
Every time that a gateway wants to do a calls, the information is sent to the gatekeeper.
The gatekeeper lokks up the number that you dialed and try to find a match on the registered gateways.
If it finds a match, sends a message back to the originating gateway, with the I.P. address of the gateway that could take the call.
The originating gateway then places a call directly to the gateway on the other end.
The voice packets do not travel trough the gatekeeper, only the “signaling” does.
There are some free gatekeepers, that could be run on a old P.C. and are for free.
Or if you have a cisco router that could do gatekeeping, and have a static I.P. address, you could use that too.
The gatekeeper is necessary only:
1)If the I.P. address of the gateways change every few hours or days.
2) You only have ATA and want to make a “network” of several ATA ‘s.
You do not need a gk to call from one ATA to another on static I.P. addresses.