Taking the example from the Making and Receiving Calls section in which we used the prefix 8 for dialing one analog line (channel 63), we will add channel 64 (but we must first create the trunk as ANALOG-TRUNK-2).

The reason for adding this channel is that whenever port 63 is being used, any user can dial 8 + an 8-digit local call and still use channel 64 to establish a call. This way of controlling outbound routes is very helpful, limiting the usage of trunks in any outbound prefix. We can add as many available trunks as we have.