Hi
1) Go to PBX – External -Trunk and fill in the fields
https://ibb.co/hnsQu7
Description – any description that you want
Codecs – choose alaw
In Peer section:
Outgoing Username – my_trunk_provider
Host – ip_to_my_provider
Insecure – choose Port, Invite
Allow Inbound Calls – choose Yes (this option enable parameter type=friend)
From Domain – ip_to_my_provider (parameter fromdomain=ip_to_my_provider)
Qualify – choose Yes
In User section:
Insecure – choose Port, Invite
IP Autentification – Yes
Qualify – Yes
Register String – Use Default – No (if you no need register string for your provider)
After that choose ADVANCED tab on the top of page and fill the fields
https://ibb.co/cs3b1n
Type = Friend Parameter = canreinvite Value = no
Type = Friend Parameter = dtfmmode Value = rfc2833
2) For removing +1 from incoming calls first use PBX – Incoming Calls – CID modifiers
Here you can use various rules to modify numbers. For removing +1 from start of number just set 2 in field CID Number Settings – Skip. It will ignore first two simbols in incoming calls.
https://ibb.co/mvLpMn
Than when you will create inbound route in PBX – External – Inbound Routes and choose in field Caller ID Modifier previously created modifier
https://ibb.co/fjBJE7
