Programming instructions

Atmel AT02597: ZigBee PRO Packet Analysis with Sniffer [APPLICATION NOTE]
32210A−WIRELESS−09/2013
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Figure 4-14. Fragmentation – Example.
As per ZigBee specification, the first fragment is sent with the block number as the total number of blocks comprising
the entire APL data, as seen in Figure 4-14. The subsequent fragments have block nu
mbers starting from 1 onwards up
to maximum transmission window size. The receiving node sends an APS Acknowledgment frame when all blocks in
the transmission window have been received.
Table 4-4. Config. Server Parameters Affecting Data Transmission.
Information Config. server parameter
Single Fragment size CS_APS_BLOCK_SIZE
Number of fragments /blocks the APL data is split into CS_APS_MAX_BLOCKS_AMOUNT
Number of blocks to be sent before expecting an APS ACK CS_APS_MAX_TRANSMISSION_WINDOW_SIZE
Size of a single fragment in fragmented transmission CS_APS_TX_BLOCK_SIZE
Size of one receive buffer that will hold one fragment of the
data frame.
CS_APS_RX_BLOCK_SIZE
4.8 Service Discovery
Service Discovery is the process of collecting information on supported clusters on other devices in the network.
Service discovery uses ZDP requests (with MATCH_DESCRIPTOR_CLID) for every cluster ID supported. Service
discovery requests can be unicast or broadcast and so the response contains the network address of the responder
along with the matched simple descriptor information.
The response contains a match list with the end-points that support the cluster in the request. Service discovery is
explained in further detail in Section 5.1.1.
4.9 Tunneling in Secure Networks
Consider a network wherein a node insecurely joins through a router parent (i.e.) the joining node does not know the
network key prior to join procedure.
In this case, the APS command used to securely communicate the network key from the Trust Center to the newly
joined router is called the APS Tunnel command.
Referring to sniffer log, Transport_key_tunnel.dcf, end-device 0x01LL joins router 0x0000000100000000 from packet
#26. The parent router sends an APS Update Device command to the Trust Center to inform the Trust Center that a
node has joined or left the network.
Figure 4-11 shows the updat
e status of the device, depending on which the Trust Center takes necessary action (i.e.) to
send the network or remove the key and associated security counters for the device.