6.3.3 Service Discovery

Node Descriptor – The router/end device requests the node descriptor during the initialization procedure before finding and binding to discover the capability information and other information of the coordinator device in the network. For more details, refer to the Zigbee Specification Revision 22 1.0 (05-3474-22).

The following figure illustrates packets #18 and #20 as the Node Descriptor Request and Node Descriptor Response from the router and coordinator nodes, respectively.

Figure 6-19. Node Descriptor
The following figure illustrates the Node Descriptor Response from a coordinator device. The user can see the following under ZigBee Device Profile:
  • Capability Information of the coordinator node
  • Max Buffer Size
  • Server Flags
  • Descriptor Capability Field
Figure 6-20. Node Descriptor Response

Simple Descriptor – After receiving the Identify Query Response from the coordinator, the router identifies the target endpoint and sends a simple descriptor request to the target endpoint (coordiantor). Packets #53 and #55 are Simple Descriptor Request and Simple Descriptor Response from router and coordinator devices, respectively. For more details, refer to the Zigbee Specification Revision 22 1.0 (05-3474-22).

Figure 6-21. Simple Descriptor – Coordinator and Router

The following figure illustrates the Simple Descriptor Response with the list of supported input and output clusters of the coordinator.

Figure 6-22. Simple Descriptor Response