Incoming Limit:

Number of simultaneous incoming calls trunk can handle

Example: 4 equals to four simultaneous incoming calls. Any additional calls will get the busy sound

Field Type: [0-9]

Outgoing Limit:

Number of simultaneous outgoing calls trunk can handle

Example: 4 equals to four simultaneous outgoing calls. Any additional calls attempting to use this trunk will be rejected  or will be redirected to other trunks depending on what is set in the system/extensions

Field Type: [0-9]

Notransfer:

Disable native IAX transfer

Example:

Field Type: Option buttons

Send ANI:

Should ANI ("super" Caller ID) be sent over this trunk

Example: Set 'Yes' to enable

Field Type: Option buttons

Trunk:

Use IAX2 trunking with this host

Example: Set 'Yes' to enable

Field Type: Option buttons