Symptoms: Maintain statically assigned IP addresses on remote IP phones IP phone takes DHCP address even though assigned directly through the phone IP phone loses its address IP Phone reboots for no apparent reason IP phone drops calls IP device loses its address

Facts: SuperStack 3 NBX

• NBX 100
• 3C10110
• 3C10121
• 3C10121
• NBX Operating System
• NBX Phones
• DHCP Server
• Assigned IP address
• IP Serve
• IP On-the-Fly
• LUI (LCD User Interface)
• Phone programmed directly through the LCD User Interface (LUI)

Causes: This condition is the result of a caveat in using NetSet . It becomes apparent on systems running in IP Serve or IP On-The-Fly Mode (in all versions up to NBX R4_0). This affects ALL DEVICES, even devices functioning at layer 2 on the NBX local segment.

When you enter the “IP SETTINGS” screen (actually ANY “modify” screen) from the Device Configuration section to view IP information for any given device, exiting the screen by pressing the “OK” button causes the system to (re-)apply all IP values in the “Manually Assigned” section, and to reboot that device. On all NBX configuration screens, “OK” means “Apply and Exit”. So pressing OK Applies the manually assigned settings and reboots, even though you may not have intended this. Always press “CANCEL” on any screen unless you intend to update the device with the settings shown in that screen.

Result:

1. The device REBOOTs as you exit with “OK”–always. So, if there is a call in progress, it disconnects. Use “Cancel” instead. This is true even if the device is NOT currently running in IP mode (local device). It will reboot and drop the call!

2. If you have assigned IP settings for this device manually in NetSet, the reboot apparently has no adverse effect other than rebooting it, which will drop any existing call. However, if the device shows “IP Settings Reported By Device” (which means either it was a phone programmed via LUI , or the device has obtained a DHCP address), THESE SETTINGS ARE LOST, and are overwritten with whatever is in the Manually Assigned address fields in NetSet.

3. If it is a DHCP device, it forces another Request for Lease (which may not be a serious problem). However, if you used LUI to configure the IP settings on the phone, clicking OK in this screen will cause the phone to LOSE all its correct IP information and STOP WORKING. It then automatically tries to get an address from a DHCP server on its subnet (you purposely may have provided it with a distinct IP address and may not want that to happen) or, if there's no DHCP server, it attempts to find the NBX Call Processor at Layer 2, and gets “hung” as it is a remote IP phone. The only recourse is to program that phone again, either locally via LUI, or via NetSet while it is connected to the “home” sub-net.

Fixes: Workaround: In NetSet always use “Cancel” when not making specific changes from a screen, as “OK” does an APPLY (or re-apply) of existing settings on that screen.

NOTE 1: IP settings shown in LUI on a phone do not necessarily show what the phone is currently using - it mearly shows the LUI register memory for what was last assigned in LUI.

NOTE 2: Setting IP Values in LUI and rebooting will cause the phone to try to use those values, but if the phone at some future point receives new IP settings via NetSet Manually Assigned, or DHCP, the LUI screen will show incorrect values.

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

— David Gonzalez 2021/04/12 08:12