ascom
Ascotel 2025/2045/2065
6.1.3.1
Connections between Nodes
Determine the nodes to be connected with one another:
• The topology can be star-shaped, meshed or a combination of both.
• For reasons of connection reliability it is advisable to ensure that each system
can be reached via at least 2 independent routes (requirement for overflow
routing). See also "Reliability Aspects", Page 3.95.
• If possible specify which connections are best implemented virtually via the
public network (e.g. also the integration of GSM subscribers into the private
network).
6.1.3.2
Accesses to the Public Network
Determine which systems are to have accesses to the public network:
• Which systems are to have virtual networking via the public network? This
question is to be addressed in connection with the type of connection between
two systems. Virtual networking is particularly appropriate for greater distances
with a relatively small volume of traffic.
• On which systems should calls be routed to the public network?
The traffic volume on a system on the public network (gateway PINX) is the sum
of the volume of traffic of the system's own traffic and the volume of traffic of
all the systems in the network that telephone out into the public network using
that system. The same applies accordingly for systems that forward calls from
one system to another (transit PINX).
• To which system are calls with the main number routed?
• On which systems are calls from the public network to be routed directly to
subscribers in the private network (direct dialling in)?
– Should the subscribers be obtainable via several DDI numbers?
– Should incoming calls be routed in accordance with break-in criteria? This
requires additional DDI numbers for a correct CLIP indication, see part 2
under Break-In).
• Where are additional connections to the public network required for overflow
routing compatible with emergency operation? (See also "Reliability Aspects",
Page 3.95.)
3.90
Planning a Private Network
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