ASCOM Ascotel 2025 - Private ISDN-Based Network (PISN)

ascom Ascotel 2025/2045/2065
HBT_20321104_01/B0_en Networking the Systems 1.27
4.1 Private ISDN-Based Network (PISN)
A private network based on the ISDN standard is referred to as a PISN (Private Inte-
grated Services Network). Its characteristic feature is that all connected subscrib-
ers can communicate with one another in the same way as PBX-internal subscrib-
ers. This applies to both voice traffic and to ISDN-based data traffic. A PISN is the
keystone of any corporate communication structure optimized in terms of flexibil-
ity, user convenience and cost.
A network is generally defined by its nodes and the connections between those
nodes. In a PISN they are formed by ISDN PBXs. A PISN consists of at least two
nodes and can be structured both as a meshed network and as a star-shaped net-
work. Hybrid forms are also admissible.
Usually a PISN is connected to the public network in at least 1 place.
Fig. 1.14: PISN with at least two nodes
Fig. 1.15: Star-shaped and meshed PISN
PISN
ISDN
PBX 1
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ISDN
PBX 2
PISN
ISDN
PBX 2
ISDN
PBX 1
ISDN
PBX 3
PISN
ISDN
PBX 2
ISDN
PBX 1
ISDN
PBX 3
Star-shaped network
Meshed network
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