User guide

IP Network Connections 157
PBX Networking
Connection via an Active Transmission
System
For distances exceeding the range of a direct connection, an
active transmission system can increase the range to up to 50 km.
Normally the L1 master is the transmission system for the two
connected PBXs. For the protocol layers L2 and L3, one PBX is
normally the protocol master and the other PBX is the protocol
slave.
Connection by an active transmission system
Note: The active transmission system itself gets its L1 clock
either from the network operator or from a clock generator con-
nected by wire.
Connection via the Public Network
Point-to-point connections via the public network of a network
operator can be used for bridging distances beyond 50 km. Due to
the long distance involved, for technical reasons it is not possible
to synchronise the L2 protocol. Consequently, the public network
is normally the protocol master for protocol layers L1 and L2. One
PBX is therefore the L3 master and the other PBX the L3 slave.
Point-to-point connection via a public network
IP Network Connections
If you are operating a fast and continuous network or internet
connection at two or more sites, you can also network the PBX
systems via a network connection.
There are two different protocols available for networking TC sys-
tems via network connections: Q.SIG-IP and SIP tie line. The vari-
PBX 1
L1 slave
L2 master
L3 master
PBX 2
L1 slave
L2 slave
L3 slave
Transmission
System
L1 master
PBX 1
L1 slave
L2 slave
L3 master
PBX 2
L1 slave
L2 slave
L3 slave
Public
network
L1 master
L2 master