Logical Link Control

Channel Identifiers

The predefined L2CAP Channel Identifiers can be found within the Bluetooth^® Core Specification, in Volume 3, Part A – Logical Link Control and Adaptation Protocol Specification.

Protocol and Service Multiplexers (PSMs)

Protocol	PSM	Reference
SDP	0x0001	See Bluetooth Service Discovery Protocol (SDP), Bluetooth SIG
RFCOMM	0x0003	See RFCOMM with TS 07.10, Bluetooth SIG
TCS-BIN	0x0005	See Bluetooth Telephony Control Specification / TCS Binary, Bluetooth SIG
TCS-BIN-CORDLESS	0x0007	See Bluetooth Telephony Control Specification / TCS Binary, Bluetooth SIG
BNEP	0x000F	See Bluetooth Network Encapsulation Protocol, Bluetooth SIG
HID_Control	0x0011	See Human Interface Device, Bluetooth SIG
HID_Interrupt	0x0013	See Human Interface Device, Bluetooth SIG
UPnP	0x0015	See [ESDP], Bluetooth SIG
AVCTP	0x0017	See Audio/Video Control Transport Protocol, Bluetooth SIG
AVDTP	0x0019	See Audio/Video Distribution Transport Protocol, Bluetooth SIG
AVCTP_Browsing	0x001B	See Audio/Video Remote Control Profile, Bluetooth SIG
UDI_C-Plane	0x001D	See the Unrestricted Digital Information Profile [UDI], Bluetooth SIG
ATT	0x001F	See Bluetooth Core Specification​
​3DSP	0x0021​	​​See 3D Synchronization Profile, Bluetooth SIG.
​LE_PSM_IPSP	​0x0023	​See Internet Protocol Support Profile (IPSP), Bluetooth SIG
OTS	0x0025	See Object Transfer Service (OTS), Bluetooth SIG
EATT	0x0027	See Bluetooth Core Specification

CID Name Space

The CID name space for the ACL-U, AMP-U, and LE-U logical links that are defined can be found within the Bluetooth Core Specification in Volume 3, Part A – Logical link Control and Adaptation Protocol Specification.

The ACL-U and AMP-U CID Name Space

Value(s)	Reference for Definitions
0x0000-0xFFFF	Bluetooth Core Specification Vol 3, Part A, section 2.1 (all versions v2.1 + EDR and later), Table 2.1

The LE-U  CID Name Space

Value(s)	Reference for Definitions
0x0000-0x001F	Bluetooth Core Specification Vol 3, Part A, section 2.1 (all versions v2.1 + EDR, and later), Table 2.2
0x0020-0x003E	Reserved for future use
0x003F-0xFFFF	Bluetooth Core Specification Vol 3, Part A, section 2.1 (all versions v2.1 + EDR, and late), Table 2.2