bearerbox and smsbox need to be started separately.
When starting smsbox, link in the bearerbox container.
in one terminal, run;
docker run -it --name=mybearerbox komuw/kannel_bearerbox:v1.0
and in another terminal run;
docker run -it --name=smsbox --link=mybearerbox:mybearerbox komuw/kannel_bearerbox:v1.0
make sure that in your /etc/kannel.conf file, the bearerbox host is set to the linked container. eg
$ cat /etc/kannel.conf
/# SMSBOX SETUP
group = smsbox
bearerbox-host = mybearerbox #the name of the linked container
sendsms-port = 13013
log-file = "/var/log/kannel/smsbox.log"
log-level = 0