BlueGate 2100
Appendices—A: Intro to BT
July 26, 2001
WIDCOMM, Inc, Proprietary and Confidential
A-4
Link Keys
To avoid entering a passkey over-and-over for a known and trusted remote device, a link
key can be created.
A link key is a number created from:
•
The passkey.
•
The Bluetooth device address of the remote device.
•
An internally random-generated number.
There is no limit to the number of link keys that may be created.
Devices that share a link key are “bonded.” Bonded devices are authenticated
automatically, without operator intervention.
S
ERVICES
The software that allows a Bluetooth device to act as a server is known as a
service
.
Enabled services are started automatically when the computer boots. The services then
run as background tasks.
Typical Bluetooth services include:
•
Local Area Network access.
•
Dial-up networking.
•
File transfer between computers.
•
Object exchange between computers.
•
Serial port emulation.
•
FAX device support.
•
File system synchronization.
NOTE: BlueGate only supports one service—Local Area Network access using PPP (LAP).
D
EVICE
I
NQUIRY AND
S
ERVICE
D
ISCOVERY
To connect to a remote Bluetooth device, the remote device must:
•
Be within radio range.
•
Provide a Bluetooth service.
•
Be accessible, from a security standpoint, by the local device.
Device Inquiry
A Bluetooth device must be within radio range of a second Bluetooth device to establish
a connection.
Every Bluetooth device keeps a list that contains the user-friendly name and device
address of each remote device that is within its radio range.
As Bluetooth devices wander in and out of the Bluetooth Neighborhood the list must be
updated. This is accomplished in two ways:
•
The list is updated automatically when the local device periodically queries all
other Bluetooth devices within range.
•
The list can also be updated as necessary by selecting an on-screen option.