This section provides information about channel groups, to which you can allocate some of the channels on a trunk.
A channel group is a set of channels that share the same characteristics. By default all the channels on a trunk belong to the same group. But to have channels with different characteristics on the same trunk, you can allocate some to one group and some to another. There are 16 channel groups, numbered 1 through 16.
Each channel group can use a different line signaling protocol, call direction, incoming or outgoing address signaling protocols, and area code. For example, if the Trunk Interface type is T1, one channel group can use the E&M trunk protocol and another the FXS trunk protocol. You could have two channel groups using FXS, one to support incoming calls, and another to support outgoing calls.
If you require channels with different mixtures of line signaling protocol, call direction, incoming and outgoing address signaling protocols, and area code, you need to plan your channel groups carefully before allocating all the channels.
The channels in a channel group can belong to multiple trunks, so changing the channel group setting changes the characteristics of all the channels in a the group, whichever trunk they belong to.
New channel groups can only be defined in the trunk configuration menu, as channel groups must be assigned to a trunk before they can be edited. Existing channel groups can be updated through the channel group menu, or in the trunk configuration menu.