3.10.3.2.3. Requirements 
IP requirement:
In order for the IP terminals to access the DLS and DCMP, both must
be accessible for the IP terminals via a public IP address. In other
words from the Internet in the case of the remote office scenario.
Hardware requirement:
The DLS server requires two network cards for this solution. One network
card sets up the connection to the corporate/enterprise network and the
second is intended for the connection to the IP terminals in the Internet/NAT
router.