Route Cache Sizing and Checkpoint Configurations

The Route Cache holds subscriber identity data and session identity data that maps either subscribers or sessions to particular customer sub-domains. The Traffic Routing Agent (TRA-RT-(SI/DR)) and the Network Enabler use the Route Cache to look up routing information when processing network requests. You can use the configuration settings below for sizing the Route Cache and creating Route Cache checkpoints.

Route Cache Table Sizing

The Route Cache Controller (RCC) configuration includes definitions of the available Route Cache tables, such as the subscriber identity table and the session identity table. Cached subscriber identity data is updated infrequently, and the data is more or less static. The identity data includes items that identify the subscriber, such as the subscriber ID, IMSI, MSISDN, and login ID. Cached session data is constantly updated and contains only the session ID for identifying actual sessions in real-time, such as voice or data sessions. Each cache is held in a separate table.

Size the Route Cache tables according to your business needs. Use the expected size of your subscriber base and the expected sessions (generated by event-transaction) identified by your performance testing when deciding table sizes. You define sizing configuration for each Route Cache table in the Route Cache Controller configuration properties file (rcc_base.cfg).

Auto-size Route Cache Tables

Instead of specifying the size of the route cache tables up front, optionally, you can configure the RCC to calculate the susbscriber and sessions table capacity automatically based on available shared memory. The create_rc_config.py script uses the following process to auto-size the Route Cache tables:
  1. Obtains the total and shared memory values from the system or, if set, using the create_rc_config.py script command line arguments.
  2. Checks the headroom percentage and the size specified for the Route Cache admin table.
  3. Subtracts the headroom percentage and admin table size form the shared memory to find the available shared memory.
  4. Calculates the number of bytes needed per subscriber.
  5. Calculates the Route Cache table capacities based on available shared memory and the number of bytes needed per subscriber.
For example, for the following values:
  • Total memory available — 23378 mb
  • Total shared memory available — 11689 mb
  • Total memory used for admin tables — 82 mb
  • Total memory used for route cache tables — 443 mb
  • Number of supported subscribers — 270000
The auto-sized subscriber table capacity is 1890000, and the auto-sized sessions table capacity is 1620000.