CO lines can be grouped into trunk groups based on carrier, CO line type, etc. Several settings can be assigned on a trunk group basis. All CO lines belonging to a trunk group follow the programming for that trunk group. → 2.9.1 [3-1-1] Trunk Group—TRG Settings → [402] LCOT Trunk Group Number
Each CO line can belong to only one trunk group. CO lines are assigned to a trunk group based on their port numbers (for LCOT and PRI cards) or their channel numbers (for T1 cards).