Packet buffer usage

Packet buffer usage on a router or coordinator varies depending on the application. The following activities can require use of packet buffers for up to several seconds:

• Route and address discoveries
• Application broadcast transmissions
• Stack broadcasts (for example ZDO “Device Announce” messages when devices join a network)
• Unicast transmissions buffered until acknowledgment is received from destination or retries exhausted
• Unicast messages waiting for end device to wake

Applications that use regular broadcasting or that require regular address or route discoveries use up a significant number of buffers, reducing the buffer availability for managing packets for end device children. Applications can reduce the number of required application broadcasts, and consider implementing an external address table or many-to-one and source routing if necessary to improve routing efficiency.