Beestack multicast route discovery issues

[chrisbroadbent]

I'm doing some experimenting with beekit, and am having issues with multicasts under very specific circumstances:

• Zigbee pro
• All members of the multicast group are end devices
• The message is sent from someone outside the group

Since the message is from outside the group, the sender will do a unicast transmission to a member of the group, who will then perform a broadcast. The problem is that the route discovery command to find a member of the group never gets delivered to end devices, and therefore never gets delivered to a group member, so a route is never found, and the multicast message is never sent.

The process works find when there is a router that is part of the group, but not when there is only end devices.

Any way to fix this, besides turning on the use broadcast for group messages option?

[AlanCollins · Accepted solution]

Hello Chris.

        What you are trying to achieve is not allowed by ZigBee spec. You are trying to make an ZED to have routing capabilities (NWK Layer) which is out of the scope of the ZED. Only ZC and ZR can be part of a routing process. Also, route Request is intended to find routes to specific nodes. What you need to to find a node with specific configuration.

The first option is have the sender joining the group.

The second option you have to solve this, is by adding ZC or ZR in the multicast group.

The thrid option is to identify the one member of the group by Application level. The "gNwkGroupIDTable_c" variable inside the NIB has the number of groups the node is member of. This numbers defines the number of valid entries inside the Group Ide Table. There's also the You can search for nodes with this value higher than 0, then ask them individually to get their group address. You may also use the "apsGroupTable" (APS layer), that tracks groups associated to specific endpoints.  

The fourth option is make the ZED to report to his parent every time it joins a new group.

I hope this helps.

Best Regards,

Alan Collins