As the doc said, the ENP should works with FXSs and SIP phones, I follow the link and do some test with ENP:
I found the ENP could not work properly. the results are:
- When PBX down, the sip accounts can re-register to VEGA proxy and SIP phones can call each other.
- When PBX down, the sip phones can make out going call through VEGA-FXO, the mobile rings, but we can not hear each other.
- Some SIP brands works(fanvil), some maybe not(GS).
- When the FreePBX is up, the SIP phone can work and re-regiester as normal, all phones work well with outgoing calls and incoming calls.