ZTP

PnP and Zero Touch Provisioning (ZTP)

SARK V3 has on-board PnP and ZTP provisioning using a SIP Multicast listener/builder. This has a couple of major benefits for users of SIP phones that are SIP/PnP aware:-

  * There is no need to run DHCP option 66, and no need to run an on-board DHCP server.
  * The provisioning stream is synthesized by the listener on-demand 
  * No tftp or ftp file to be hacked.
  * New phones can optionally be provisioned and defined to asterisk on-the-fly by the listener/builder.
  

Supported phone types

In the initial delivery SARK V3 has support for Snom and Yealink phones. Support for Gigaset phones is planned but only for Intel based platforms (not PPC).

Set-up

Set-up requires only two variables to be enabled. They are in Globals-> Services and they are called:-

  * PnP Provisioning
  * Zero Touch Provisioning

PnP Provisioning

PnP (or SIP Plug 'n Play) turns on the SIP Multicast listener. This allows SARK to asynchronously tell a SIP phone where its provisioning file is located without the need to modify the existing DHCP server or to run an on-board DHCP server.

ZTP

Zero Touch Provisioning works in tandem with PnP. When ZTP is enabled then SARK will not only inform a phone where its provisioning data is but it will also build the data on-the-fly and update Asterisk at the time the phone first requests it. What this means is that you can simply power up a PnP aware phone and SARK will automatically create an extension for it in the SARK database, inform the phone where the provisioning data is and finally, regenerate Asterisk so that it is aware of the new extension. Thus the phone will come up, be automatically provisioned, register with Asterisk and be immediately ready to make and receive calls. This is very useful for medium to large roll-outs because it needs no prior set-up.

For security reasons, you should only run ZTP during intial system installation or when you have new phones to roll-out. The remainder of the time it should be switched off.

Running multiple listeners on the same subnet

In order to be able to run multiple PBX servers in the same subnet, the Multicast listener must be able to selectively reply to only those PnP aware phones which it "owns" (i.e. are defined to it). For this reason, unless ZTP is enabled, SARK will only respond to requests from phones for which it already has an entry in its database. It recognises individual phones by their MAC addresses. This mode of operation is much the same as regular DHCP 66 type provisioning; i.e. only phones which have been predefined to the system will be provisioned. In this way, multiple servers may all be listening for Multicasts and each can respond to its own group of phones without disrupting other listeners.