PAGING, CONFERENCING, PHONES CAN NOT SEE NCP

Symptoms: Phones not booting up

• Paging does not work in IP mode
• Conference does not work in IP mode
• BLF does not work
• No illumination on remote IP phone
• Date and Time is wrong on remote IP phone
• Mapped Line does not work on remote IP phone
• Cannot page from a remote IP phone
• Cannot initiate a conference from a remote IP phone
• Date is incorrect
• Date is wrong
• Time is incorrect
• Time is wrong
• Conferencing does not work
• Paging does not work
• Paging fails
• Conferencing fails

Facts: SuperStack 3 NBX

• NBX 100
• NBX 100 R2_0
• NBX 100 R2_6
• NBX 100 R2_8
• NBX 100 R3_0
• IP On-the-Fly
• IP Serve
• NBX Basic Phone
• NBX 1102 Business Phone 10 Mb
• NBX Attendant Console (Adjunct) NBX pcXset
• Multicast traffic
• IP multicast traffic
• Conference

Causes: On R3.x and earlier, Layer 2 NBX devices do not do IGMP join requests so any switches with IGMP Snooping enabled will drop those packets. The applications effected by this issue are those using an IP Multicast address at Layer 2. These applications include paging, conferencing and communication with NCP on bootup. Most vendor switches have IGMP enabled by default which means that any Multicast traffic will not be forwarded unless there is a request for that particular Multicast address which we do not support.

On R4.x and higher, the MAC or Layer 2 address has been changed so that IGMP Snooping can be enabled or disabled and it will not disrupt communications.

Any code revision that has remote, IP, devices need to have IGMP snooping and Multicast Routing enable for these same functions to work properly.

Fixes: The following are required for to support Paging, Conference, BLF lamps, Mapped POTS Lines, and Date and Time Display updates on remote IP phones, and in some cases even on the network LOCAL to the NBX when the NBX is operating in IP or IP-On-The-Fly mode:

• 1. Physical gateway (router) on same subnet must exist and be operational.

• 2. NCP's network configs must be correct (IP address, subnet mask, and gateway)

• 3. IGMP and Multicast Routing Protocol must be configured and enabled throughout the connection for remote IP phones (all routers and layer 3 switches must support IGMP)

NBX uses the system gateway (router) to send Paging packets, even on the same network if IP is enabled. This is unlike regular NBX phone calls, which always attempt to use layer 2 on the same subnet, even if the system is running in IP mode. A valid gateway must exist, and the NBX's IP settings must all be correct and non-conflicting for the network on which the NBX is running.

If you can reboot the system in Ethernet mode and your paging problem is resolved, you have a gateway or network configuration issue.

Anomalies:

• Remote IP phones can receive pages from all sites, but phones local to the NCP cannot receive pages from remote IP phones.
• Remote IP phones can participate in a Conference call, but cannot initiate a Conference call

These are known limitations.

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

— David Gonzalez 2021/04/12 08:56