Route Analysis

The route analysis is a process of table query and data analysis. Figure 1 illustrates the process for analyzing how to route an outgoing call over ISUP trunks.

Figure 1 Route analysis process

Assuming that a local subscriber has originated an outgoing call, the MSOFTX3000 performs route analysis in the following way:

1. The MSOFTX3000 looks up the Call Prefix table for Route selection name of the called prefix, that is, the route selection strategy planned for the called prefix.
2. The MSOFTX3000 looks up the Route Analysis table for a record that matches Route selection name. By analyzing Route selection source name, Caller category, Address information indicator, Transmission capability, and Time segment name in the record, the MSOFTX3000 decides whether to grant a route to the current call and which route is to be granted. If the analysis is successful, the MSOFTX3000 obtains the name of the selected route.
3. The MSOFTX3000 looks up the Route table for a record that matches the route name. According to the subroute selection strategy in the record, the MSOFTX3000 selects the subroute to be used and obtains the name of the selected subroute. There are two strategies for subroute selection: sequential selection and percentage-based selection.
4. The MSOFTX3000 looks up the Sub-Route table for a record that matches the subroute name. According to the trunk group selection strategy in the record, the MSOFTX3000 selects the trunk group to be used and obtains the number of the selected trunk group. There are two strategies for trunk group selection: cyclic selection and random selection.
5. The MSOFTX3000 looks up the SS7 Trunk Group table for a record that matches the trunk group number. It then analyzes the record to select a trunk circuit on a particular MGW. It also obtains the internal number (circuit number) of the selected trunk circuit.

NOTE:

The commonly used circuit selection modes are Maximum, Minimum, Master/slave, and Cycle.

• Maximum: Among the available circuits, the system always selects the circuit with the maximum circuit number on the WCCU/WCSU with the largest module number.
• Minimum: Among the available circuits, the system always selects the circuit with the minimum circuit number on the WCCU/WCSU with the smallest module number.
• Cycle: Among the available circuits, the system always selects the circuit that is first released. The circuit selection is based on the circuit numbers (which are numbered within one module) but not the CICs, and thus you must configure the circuit with a smaller CIC to the module with a smaller module number if the circuits in an office direction must be configured to multiple modules. This ensures that circuits can be selected based on the CICs.
• Master/slave: If a master circuit is available, the system always selects the master circuit. The system selects the slave circuit only when no master circuit is available. Therefore, coordinate with the peer MSC server when setting the Master/slave circuit selection mode. If the peer MSC server uses the even master circuit selection mode, the local MSC server must use the odd master circuit selection mode. If the circuit selection mode of the local MSC server does not match that of the peer MSC server, circuit dual-seizure occurs frequently and the call completion rate is affected.
5. The MSOFTX3000 looks up the SS7 Trunk Group table or a record that matches the trunk circuit number. From the record, it obtains the E1 timeslot ID (TID) that is mapped to the trunk circuit number.
6. The MSOFTX3000 sends an H.248 message with the TID to instruct the MGW to select the required trunk circuit.