Symptoms:

• Implementing remote IP devices with and without DHCP server
• NBX telephone does not receive DHCP information
• NBX telephone receives DHCP information even though hard coded through phone set
• Trouble setting up option 184
• Analog Line Card, Analog Terminal Card or Analog Terminal needs to be shipped back for re-configuring
• IP device may not be setup correctly
• Getting unexpected results when configuring a remote IP device

Facts:

• SuperStack 3 NBX
• NBX 100
• IP On-The-Fly
• IP Serve
• DHCP
• Option 184
• Remote IP
• VoIP

Fixes: Please read the following when considering implementation of NBX layer 3 devices on remote networks

NOTE : T1 cards must be on the same IP sub-net as the NCP - no remote chassis T1 card setups!

3 Basic implementations can be configured for remote IP Phone/Card implementations:

• A remote IP phone/device can have full IP information programmed statically into the it, and ignore DHCP servers
• A remote IP phone/device have the NCP IP address only programmed statically into it, and use DHCP for its own address
• A remote IP phone/device use full DHCP function to obtain its own address information and the NCP address (option 184)

Rule Set of how an NBX device (except the DLC) operates when it boots up:

A. The device beacons at layer 2 for an NCP at the NCP mac address programmed in the phone. By default, this value is all Fs (ethernet broadcast address) and will attempt to find any available NCP.

B. If one (and only one) NCP is found at that MAC address, it will attempt a connection at layer 2. If a 2nd NCP is found at layer 2 at that MAC address, message appears in phone display “pick an nboss” and will not boot up. If this is not a phone, you will not get any indication other than the device will not boot up as their is no LCD display telling you this message.

C. If no NCP is found at the mac address at layer 2, it reads any internal IP settings hard-coded into the phone. If NO hard coded IP settings exist, the phone will send a DHCP request packet and attempt to negotiate a DHCP address. If there exists IP settings hardcoded into the phone, it will: 1] arp the network for that IP address to confirm no other device is using it, 2] arp the Default Gateway IP to confirm it exists. If Either of these 2 conditions fail, the phone will request DHCP. If it passes those tests, it will then attempt to find an NCP at the IP settings (subnet mask, default gateway, and NCP IP), configured within. If it finds the NCP at the exact IP settings loaded in the phone, it will attempt a connection. If it is unable to connect to the NCP for any reason at the hard-coded address (wrong IP subnet, gateway, no route possible, or if the WAN connection is down), it will send out a DHCP request.

D. If a DHCP ACK packet is returned, it will negotiate and take IP settings from the DHCP server's scope. DHCP Scopes can be configured specifically as to what information they issue, but usually give an IP address, subnet mask, and default gateway IP address. Other IP addresses information (such as the NCP IP address ) can be set up on the DHCP server using customer option 184, but not necessary. If you wish, you can program the NCP IP address (only) through the phone's front panel, and let the phone obtain the rest of the DHCP information according to the DHCP scope.

E. The NBX phone will also “ask” for information contained in Scope Option 184. If the DHCP server is set up specifically to give it, the phone would accept and load the option 184 IP address. Option 184 can be set up on Microsoft DHCP server to issue an IP address, which is loaded onto the DHCP server as the NCP IP address, which the phone needs in order to function as an IP device across a router from the NCP in a routed network. If the DHCP server option 184 is not set up, the phone simply will not get that part, but will load with the rest of the IP information. If you have programmed the NCP info ahead of time direct into the phone, it will boot with the combination of hard coded NCP IP address, and negotiated DHCP information less option 184.

In NetSet , Device Configuration, IP settings screen, both the “IP Settings Reported by Device” and the 'Manually Assigned IP Settings' are listed. Unless you intend to reboot that device with the values shown on this screen under “manually assigned IP settings” DO NOT press the “OK” (or Apply) button.

Pressing “OK” (Apply) will ALWAYS cause the device to reboot, and will download the Manually Assigned Settings, even if you made no changes to the screen. Always press “CANCEL” instead. Otherwise, a phone that you programmed IP info to directly will now look for a DHCP server, and will not boot until IP information is restored to it.

Procedure for installing a remote IP Attendant Console, or ALC / ATA / ATC in a remote NBX chassis on a different subnet which you wish to be “homed” to the local NBX NCP:

1. Install the device on the same segment or chassis as the NBX with the NCP
2. Ensure it operates and that your NBX is booted in either IP-On-The-Fly or Standard IP mode
3. In NetSet, Device Configuration, IP settings screen, enter the values in “Manually Assigned IP Settings” that the device will be using AT THE REMOTE NETWORK. This means enter here the remote IP settings that apply to the remote network segment the device will be going to
4. Press APPLY. This will cause the device to reboot and “burn in” the IP settings on the device
5. Allow the device to come backup, ensure both that it still works, and when pressing the “IP Settings” button, that the IP settings reported by device have been loaded and double-check the IP settings (remember, don't click OK or Apply).
6. Power down the device, and physically ship or move it to the remote network
7. Connect* the device to the remote IP network segment. It should now function using the IP information you specified.

If the “remote” site (B) happens to have it's own NCP (you want this device to use the site A NCP) you MUST disconnect the site B NCP from the LAN before connecting power to the device at site B. Per rules c, d, or e above, let the device look for a local (site B) NCP (and not find one), and then use it's internal IP settings to home itself to the site A NCP. Once it is working on the site A NCP, then reconnect the site B NCP to the LAN.

• Product(s): NBX
• Sub Product(s): NBX 100, SuperStack 3 NBX

— David Gonzalez 2021/04/13 09:21