You can use a different protocol on each trunk, provided you do not mix E1 and T1 protocols on a single system. Some of the trunks can use CAS protocols, and others can use CCS.
Two Blueworx Voice Response principles, signaling type and channel group, enable you to use more than one channel associated signaling (CAS) protocol on different channels on the same trunk. Different channels on the same trunk can therefore interact with the switch in different ways to provide varying features for different applications.
A signaling type is the definition of a signaling protocol to be used by channels on one or more trunks. For example, one signaling type can define timing and signaling to be used on an E&M trunk that uses wink start. Another can define timing and signaling to be used on an E&M trunk that uses delay start. A third can define timing and signaling to be used on an FXS trunk.
A channel group is a set of channels on one or more trunks, using the same signaling type. Every channel must belong to one and only one channel group. All the channels can belong to the same group.
You can create a total of 16 channel groups. Which channels belong to which group is your choice; define the members of each group by setting the Channel Group parameter for each channel.
Each channel group can use a different signaling protocol. 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 loop start signaling, and another to support ground start signaling.
With common channel signaling (CCS), one signaling protocol provides signaling information for all channels on the trunk, so no signaling type definition is needed.
You can divide the channels into channel groups if you are using common channel signaling (CCS), although it probably is not necessary if you are using only one CCS protocol. In this condition, you can have all the channels in channel group 1. By default pack configuration assigns all the channels on a trunk into a single channel group except for trunks 13,14,15, and 16, which are all assigned to channel group 12.