Hello,
it would be great to discover hardware network phones, for example Polycom CX and HP 4110/4120.
Even if they don't have an admin interface, at least, we will have the knowledge of their existance, number, MAC-adresses (from which we can know their producers), connection to specified ports of network switches.
If those phones are USB-connected to PCs, then we will be able to find even more from the PC's OS.
Thanks.