This is on a EchoLife HG556a
You can't see the setup using the default login account "vodafone".
If you use "advanced/advanced" you can access the Admin maintenance pages, and new menu options.
There is an area for Voice, where you can set a SIP server, SIP account etc.
Its even pre-populated with SIP.Vodafone.co.nz - but as far as I'm aware, Vodafone don't offer VoIP services? or am I missing something?
Hope anyone can shed light on this.