The four digits used to differentiate trunk groups using the same IP address.
Since only 1 [IP, Port, and Protocol] configuration can be added against 1 Origination Trunk and 1 Termination Trunk, you can reuse the same [IP, Port, and Protocol] configuration as long as you add a Tech Prefix for the other Trunk Groups.
The tech prefix can be used to differentiate between trunk groups for any other reason.
Special characters are not allowed.
Peeredge automatically removes any "#" from an incoming DNIS.