Bluetooth Asynchronous Connectionless (bthci_acl)
ACL frames are used to transfer non-realtime data between nodes in a Bluetooth network.
The purpose of ACL is to provide a connection between one node and another node(unicast) or a set or other nodes(multicast). ACL provides the mechanism to send large PDUs between the nodes by a fragmentation mechanism that supports transferring PDUs up to 64kbyte in size.
BTL2CAP: The only protocol running ontop of BTHCI_ACL is L2CAP.
No. Time Source Destination Protocol Info 11 5.731294 L2CAP Sent Echo Request Frame 11 (57 bytes on wire, 57 bytes captured) Bluetooth HCI H4 Sent ACL Data Direction: Sent (0x00) HCI Packet Type: ACL Data (0x02) Bluetooth HCI ACL Packet .... 0000 0010 1001 = Connection Handle: 0x0029 ..10 .... .... .... = PB Flag: Start Fragment (2) 00.. .... .... .... = BC Flag: Point-To-Point (0) Data Total Length: 52 Bluetooth L2CAP Packet Length: 48 CID: 0x0001 Command: Echo Request Command Code: Echo Request (0x08) Command Identifier: 0xc8 Command Length: 44
The BTHCI_ACL dissector is fully functional and can reassemble fragmented PDUs.
There is a HCI_ACL preference to control whether Wireshark shall reassemble PDUs spanning multiple fragments or not.
Example capture file
A complete list of BTHCI_ACK display filter fields can be found in the display filter reference
Show only the BTHCI_ACL based traffic:
You cannot directly filter BTHCI_ACL protocols while capturing since currently you cant capture at all.
External links and Captures
See Bluetooth for example captures and links.