MAC: "00:11:22:33:44:55" Mac of the Bluetooth-USB-Stick
PIN: "1234"
Use linkkeys-files to save pairing: "YES"

Start Sdpd: "YES"
sdpd options: ""
Start Bnep: "YES"
bnep options: ""
Start Rfcomm: "YES"
rfcomm options:""

Run (once) sdptool: "NO"
sdptool options : ""
Run (once) rfcomm: "YES"
rfcomm options : "bind all"

Start Pand : "YES"
sdptool options for usage with pand: "add NAP"
pand options : "--listen --role=NAP"

Start Dund: "YES"
sdptool options for usage with dund: "add --channel=1 SP"
dund options : "--listen --pppd /usr/bin/pppd --persist --msdun call dun"

19200
192.168.178.1:192.168.178.123
local
ms-dns 192.168.178.1
noauth
debug
passive

speed
Fritzbox IP:IP for BT Device
local
ms-dns DNS-IP (mostly Fritzbox IP)
noauth
debuging to /var/log/debug
passive

# HCId options
options {

# Automatically initialize new devices
autoinit yes;

# Security Manager mode
# none - Security manager disabled
# auto - Use local PIN for incoming connections
# user - Always ask user for a PIN
#
security auto;

# Pairing mode
# none - Pairing disabled
# multi - Allow pairing with already paired devices
# once - Pair once and deny successive attempts
pairing multi;

# PIN helper
pin_helper /usr/bin/bluepin;

# Local device name
# %d - device id
# %h - host name
name "%h";

# Local device class
class 0x3e0100;

# Default packet type
#pkt_type DH1,DM1,HV1;

# Inquiry and Page scan
iscan enable; pscan enable;

# Default link mode
# none - no specific policy
# accept - always accept incoming connections
# master - become master on incoming connections,
# deny role switch on outgoing connections
#
#lm accept,master;
lm accept;

# Default link policy
# none - no specific policy
# rswitch - allow role switch
# hold - allow hold mode
# sniff - allow sniff mode
# park - allow park mode
#
#lp hold,sniff;
lp hold,sniff,park;

# Authentication and Encryption
auth enable;
encrypt enable;

00:11:22:33:44:55 12345678901234567890123456789012 0 #MAC HASHED_KEY 0 (Device 1)
77:88:99:00:11:22 88888888888888888888999999999999 0 #MAC HASHED_KEY 0 (Device 2)

Caution, for this example you have to install "bridge-utils".
brctl addif lan bnep0
ifconfig bnep0 up

rfcomm0 {

bind yes;
device 00:11:22:33:44:55;
channel 1;
comment "IPAQ3870";

...