gb-loopback is tool to control and monitor gb-loopback module.

gb-loopback [-t <type>] [-c <cportid>] [-s <payload_size>] [-m] [-w <ms>]
-t <type>: type of packet to send
           0 => Don't send message [default]
           1 => Send ping message continuously (message without payload)
           2 => Send transer message continuously (message with payload)
-s <size>: size in bytes of message payload
-c <cportid>: cportid of connection to control / monitor (-1 for all cports)
-m: display statistics about connections
-w <ms>: time to wait in ms between send of 2 packets