Ask that question to your provider.
Usualy no limit, if no special limit on provider's side.
Pregunta
I have one simple question which stuck me. I have FreePBX server with SIP trunk to ISP. ISP Dedicated one PSTN number. So all internal SIP Extension go out with the same number. Does it mean that at any time just one Extension can call outside?
Thank you. Best Regards
Solución
Ask that question to your provider.
Usualy no limit, if no special limit on provider's side.
Otros consejos
Just a hint. It would depend on your VoIP provider the number of simultaneous calls they allow you to do with one account, you can try SIP Trunk providers such as Switch2Voip Call Center VoIP they allow unlimited concurrent calls with very low rates.