...
To create test SIP calls to a Dialogic IMG Integrated Media Gateway using a hostname rather than IP address, a local DNS server is required.
Reason for the issue:
IMG Gateways support SIP calls that use a FQDN (Fully Quallified Qualified Domain Name)
Note: The following procedure was tested on a Dialogic Gate Control Element Management System (GCEMS) server running Redhat ES 3.0
IMG Gateways run a DNS client that is configured to send a DNS request to the DNS server for SIP calls.
Configuring a static DNS server on Linux Red Hat ES3:
1. Decide on a domain name.
2. Edit the /etc/resolv.conf file and add the loopback ip as the first entry in this file.
...
4. In the /var/named folder create a file for each zone created in the named.conf file above.
Create /var/named/gcems_lf.com.zone.
The following example uses these values:
Host name: lforsberg
Domain name: gcems_lf.com
Use this file to add static DNS entries.
...