Are you talking about things like the options that certain IP Phones require.
For example, Avaya IP phones require option 176 to work properly. Option 176 sets the default information that must be programmed into the phone via DHCP. It helps separate the voice from the data, sets tagging on VLANs, server ports, TFTP server, call server, etc...
Example in hand:
Data Scope for untagged VLAN:
Option 176: "L2Q=1,L2QVLAN=***" (*** is your Vlan ID)
Voice Scope for Tagged voice VLAN:
Option 176: MCIPADD=***.***.***.***,MCIPORT=1719,TFTPSRVR=yyy.yyy.yyy.yyy,VLANTEST=0 (the *** is your Call Server and the yyy is your TFTP Server)
This is a major deal for both Avaya and some Cisco IP phones for sure needing custom DHCP options.
I'm not sure exactly what smoore was referring to, but in the past, when I have set up my Avaya clients, we have to set up special DHCP options within the scope to get the phones to work properly. The option 176 I referred to in my previous post was a standard custom option.
Essentially, yes, they are helpers for VoIP applications.
I will add my voice to this since I have been asking for the same feature for quite some time. There are several applications that need DHCP options, VOIP phone configuration being only one. The lack of this support has meant putting in separate servers at sites with Astaros to handle DHCP services. There are a few like TFTP server that can be done as a straight entry, but you may want to consider something that will handle free form options since the option numbers and formats can be very different depending on what you are doing.
Attributes I use a lot :
SLPDA and Scope
eDirectory TREE and associated attributes
TFTP Server, Mitel, and Avaya Phone options
PXE Information
