Logical Link Control | Bluetooth Technology Website

Assigned Numbers are used in the Logical Link Control for protocol/service multiplexers.

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)

ProtocolPSMReference
SDP0x0001See Bluetooth Service Discovery Protocol (SDP), Bluetooth SIG
RFCOMM0x0003See RFCOMM with TS 07.10, Bluetooth SIG
TCS-BIN0x0005See Bluetooth Telephony Control Specification / TCS Binary, Bluetooth SIG
TCS-BIN-CORDLESS0x0007See Bluetooth Telephony Control Specification / TCS Binary, Bluetooth SIG
BNEP0x000FSee Bluetooth Network Encapsulation Protocol, Bluetooth SIG
HID_Control0x0011See Human Interface Device, Bluetooth SIG
HID_Interrupt0x0013See Human Interface Device, Bluetooth SIG
UPnP0x0015See [ESDP], Bluetooth SIG
AVCTP0x0017See Audio/Video Control Transport Protocol, Bluetooth SIG
AVDTP0x0019See Audio/Video Distribution Transport Protocol, Bluetooth SIG
AVCTP_Browsing0x001BSee Audio/Video Remote Control Profile, Bluetooth SIG
UDI_C-Plane0x001DSee the Unrestricted Digital Information Profile [UDI], Bluetooth SIG
ATT0x001FSee Bluetooth Core Specification
​3DSP0x0021​​​See 3D Synchronization Profile, Bluetooth SIG.
​LE_PSM_IPSP​0x0023See Internet Protocol Support Profile (IPSP), Bluetooth SIG
OTS0x0025See Object Transfer Service (OTS), Bluetooth SIG
EATT0x0027See 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
0x0000-0xFFFFBluetooth 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
0x0000-0x001FBluetooth Core Specification
Vol 3, Part A, section 2.1 (all versions v2.1 + EDR, and later), Table 2.2
0x0020-0x003EReserved for future use
0x003F-0xFFFFBluetooth Core Specification
Vol 3, Part A, section 2.1 (all versions v2.1 + EDR, and late), Table 2.2