Trunk network is a link cable connection from 1 MSC to other MSC,from 1 MSC to many MSC ,the length connection is depend on the area distance(near or long).
When Area A connect to Area B,or Province A connect to province B,So the connection between both trunk need to have signaling for connection,So that the relationship between signaling network and trunk network by using signaling point(SP) and Signaling Transfer point(STP).
Office direction
In case of there is a direct Trunk connection between two switch or from 2 MSC so it must be have an office direction, Like connection from MSC to MSC1 , MSC to MSC2 ,MSC to BSC, MSC to RNC...So need to have office direction.
Attention: Please pay attention with this note for connection between MSoftX3000 and UMG8900 of Huawei product has no office direction,but for other have.
Sub-Route (SRT)
and Route(RT)
-SRT :Sub -Route
-If there is a direct voice channel
between two offices, it is taken that there is a sub-route between them
-RT : Route
-For an office direction, the set of
all sub-routes to it is called a route, One route may contain multiple
sub-routes, and different routes may contain the same sub-routes
Trunk
circuit and trunk group
-Trunk circuit:
-The trunk circuit is the component
constituting a trunk group, and one trunk circuit corresponds to one timeslot
in E1 line
-Trunk group
-The trunk group is the component
building a sub-route, and it is a set of trunk circuits with the same
properties. It can be composed of one or multiple PCM systems.
-The trunk circuits to the same
office direction are grouped into one trunk group
-The SS7 trunk group is generally
bi-directional, and used to carry outgoing or incoming traffic.
CIC
(Circuit Identification Code)
-The CIC is used to identify a circuit
between two SPs. CIC fields only exist in the TUP and ISUP messages of circuit
switched services. Because a CIC field is 12 bits long, there can be 4096
circuits between two SPs in maximum
CIC
number principle
