1) "8xx" is the command to get an acces to certain Trunk Group (with the number "xx": 01 or 08 or 15 etc).
Inside this Trunk Group the System chooses CO-line according with an order that determined by "Line Hunting Order" setting of Trunk Group.
- Low-High order - System tryes to give a CO-line (from this Trunk Group) with the lowest number first. If the line is busy, the System tryes to give CO-line with next lowest number, etc.
- High-Low order - System tryes to give a CO-line (from this Trunk Group) with the highest number first. If the line is busy, the System tryes to give CO-line with next highest number, etc.
- Rotation order - System tryes to give a CO-line (from this Trunk Group) with the number following to the number of CO-line that was used for previous outgoing call (from highest number to lowest). When the last CO-line (with the lowest number) is reached, the System goes back to the first CO-line in group (with the highest number).
2) "9" is Local Access code (code to get an access to any available CO-line).
By this code System chooses certain Trunk Group according with Local Access Priority order (3.Group -> 1.Trunk Group -> 2.Local Access Priority).
After that the System chooses a line in corresponding Trunk Group as described above.