No local calls with Trixbox or Elastix or others : no peers, no channels, no... thing but

I am a beginner… with Asterisk solutions, sorry for my english…

I am today testing local call with Elastix.
Like Trixbox yesterday, FreePBX parameters give to me :
no peer, no channel in command line… why?
HOST Unspecified, Status UNKNOWN…

but, i have good extensions… and good Endpoint Configuration (configured without incident).

I have 3 Granstream GXP2000… and a ZOIPER configured. Are my errors here (name, SIP, password, … initialized…)?

I think to have understood that :
i have nothing else to do for local calls…
i don’t need trunk for local calls…
i don’t need DID or CID…
i found custom context to extension in extension… and gave the simplest parameters…

On elastix_without_tears, i found some screens not present on the Elastix version used, as custom contexts module… why ?

I search anywhere something to understand… and probably to activate something i’d never seen…

When i try to call I have 503 error (Grandstream), or a message that say me that local caller (2000 for example) is not identified…

I just only put extensions. It seems that i have not made inscriptions somewhere… but where ?

Many thanks

Eric

You have created extensions in FreePBX, right?
You have setup the phones with correct IP address, user, password and registrar, right?