Help needed defining DHCP option fields in 10.5 Server

According to the Unix man page for bootpd in Mac OS X 10.5 Server, the Apple DHCP server (actually called bootpd) now uses a configuration file called bootpd.plist which like other plist files is actually an XML formatted file.

Furthermore according to the same man page bootpd now (at long last) supports defining additional optional DHCP fields. One of the most common requirements needing these additional DHCP option fields is if you have a VoIP phone system. You can view this man page by typing man bootpd in the Terminal in both Mac OS X 10.5 Server and Client.

I would like to define several additional DHCP option fields to support our (Mitel) VoIP system but unfortunately I am getting errors from the DHCP server when I try this.

According to the Unix man page one should define additional properties using a name like

dhcp_option_optionnumber

e.g. dhcp_option_128

Based on other fields in the bootpd.plist file this to me suggests one should add a line like so

<key>dhcp_option_128</key>

and then again based on other entries in the standard bootpd.plist file a second line like so

<string>192.168.1.10</string>

making a total of two lines like so

<key>dhcp_option_128</key>
<string>192.168.1.10</string>

However this produces errors in the log like this

Dec 3 15:16:49 xserve1 bootpd[67218]: subnets: Failed to convert 'option_128': Failed to convert from string to opaque

The Unix man page suggests bootpd should be able to automatically convert the value inside the string section to whatever is needed to be sent across the network but obviously it is failing.

The only full example in the Unix man page looks like this

<string>dhcp_option_128</string>
<data>
AAqV1Tzo
</data>

but I think this is at least partly wrong since the first line should be using

<key>dhcp_option_128</key>

If I do try using

<data>
192.168.1.10
</data>

for the second line (in my own example) then the error does go away but without knowing how to convert a TCP/IP address to the right data value the result will be wrong.

Help!!

I want to be able to define five DHCP option fields, two of which will contain a TCP/IP address, one an ASCII string, and the other two simple integer numbers.