1

I'm looking through the Zigbee spec and the ZCL spec, and the two seem incompatible in that I cannot figure out how AF frames and ZCL commands intersect. Is the ZCL an alternative to using 'standard' AF frames, are they contained within AF frames, or is there some aspect of Zigbee that I am fundamentally missing?

SegFaults McGee
  • 321
  • 2
  • 13

1 Answers1

2

I assume by AF frame, you mean APS frame. The ZigBee spec defines the low level layer (APS and NWK layers) as well as ZDO protocol which is carried within the APS packets. As with ZDO, ZCL frames are carried as the payload of the APS frames and these protocols.

I drew the image below to illustrate the layers below the ZCL - ZDO would be substituted at the same layer as ZCL although the packet structure is a little different. Of course, below this sits the 802.15.4 frame.

ZigBee protocol layers

cdjackson
  • 137
  • 1
  • 9
  • thank you for the response, this is really helpful. I think that there must be multiple competing/outdated specifications for what can exist in the payload of an APS frame. The specification that is confusing me is here, section 1.3.4: https://www3.nd.edu/~mhaenggi/ee67011/zigbee.pdf According to this document, an entirely separate frame format exists (the "AF" frame), which is itself either a list of key-value pairs or an unspecified blob payload. I think this must be an old version of the spec. – SegFaults McGee Jun 04 '18 at 22:36
  • You are looking at a very old version of this document (r06, from 2005). I would suggest to reference something newer as ZigBee has gone through major changes since the first version (ZB Pro in 2007, then ZigBee 3). The [current public version of this document](http://www.zigbee.org/wp-content/uploads/2014/11/docs-05-3474-20-0csg-zigbee-specification.pdf) is version r20. – cdjackson Jun 07 '18 at 09:38
  • Do you know if the "Destination PAN Identifier", "Destination Address", "Source PAN Identifier", and "Source Address", defined in the MAC frame format (802.15.4 Specification 5.2.1) are the same as the fields with the same name in the NWK frame? – m4l490n Mar 14 '19 at 19:43