If I understand what you mean correctly, the DHCP server is not recognizing your device, and therefore not giving it a 'Pluto Device' IP address. In order to get Pluto to recognize the device, you have to create a template (or modify an existing one) to include the device's MAC address in the template's range of covered MAC addresses. Then, when the device is plugged into the internal network, Pluto will recognize it as a device of a certain type using the MAC address. An example is on the wiki here, for the Cisco 7960 phone:
http://wiki.linuxmce.org/index.php/Cisco_7970ISCO 7970 phone is plug-in-play device; LinuxMCE adds it automatically when it is plugged into the network. But first, we have to make some preparations. Run an Orbiter. Be sure that no others tasks are running. Check the DHCP setting of your phone. It should be something like that: "get IP via DHCP and no alternative servers". Check the range of MAC addresses:
1. Go to Advanced --> Configuration --> Device Template.
2. Chose manufacturer CISCO. You should see in the right list at least two models: 7970 and 7960.
3. Press the button 'Show model'.
4. On the opened window check 'Range MAC addresses'. The range contains two big decimal digits. To get correct range for your phone first see its MAC address. A MAC address is six groups of two hexadecimal digits, separated by hyphens (-) or colons (
. The first three groups identify a maker. You leave them and fill the rest by 0 and F. For example, if MAC is 00:16:78:CD:01:D8 its range will be 00:16:78:00:00:00 - 00:16:78:FF:FF:FF. After that you should convert those two values into LinuxMCE representation. To do that run a script /usr/pluto/bin/convert_mac and pass the hexadecimal values as parameters:
/usr/pluto/bin/convert_mac 00:16:78:00:00:00
/usr/pluto/bin/convert_mac 00:16:78:FF:FF:FF
As result you will get two big decimal digits. Add them to the phone template and store.