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openwsn-berkeley / dissectors

6TiSCH/IEEE802.15.4e Wireshark dissectors
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PAN ID compression not properly interpreted #3

Closed mstaflex closed 9 years ago

mstaflex commented 9 years ago

I am sending EBeacons (version 2 + IE bit set) with ext. src addr and enabled PAN compression, however the dissected output shows a parsed src. PAN ID, which shouldn't be there (leading to cascade parsing errors).

Details: My FCF[0]&[1] is 0x40 0xe2 => Beacon - Ver (2), Frame, Sec. (False), Pend. (False), Ack (False), Compr. (True), SeqSupr. (False), IE Present (True), Dst.Addr. (Not present), Src.Addr. (Extended address), SrcPAN (False), DstPAN (False)

This case is covered by line six in Table 2a--PAN ID Compression in 802154e-2012, which should result in no included PAN ID (neither src. nor dst.).

This parsing error is not so crucial, because beacons without any PAN ID might not occur too often in reality.

(I am using wireshark version 1.99.7 and the repo version with hash be5bb101bbcc0d93178eaa2d1fd95b0946e15a65 from July 1)

screenshot from 2015-07-01 15 31 39

mstaflex commented 9 years ago

As discussed in #4 the observed apparent "error" is rather intentional. The PAN ID compression specification in IEEE802.15.4e is still WIP and inconsistent. Hence, this issues is non-relevant for the time being.