1. Essentials Guide
  2. The Session Load Balancer and Route Manager
  3. Functional Overview
  4. Oracle CSM's Role as S-CSCF

Oracle CSM's Role as S-CSCF

The Oracle Communications Core Session Managers that participate as S-CSCFs in an SLRM load balanced deployment are responsible for performing these key functions:

  • Sends information about itself to the SLRM, including:
    • Cores serviced—The user configures Oracle Communications Core Session Manager registrars with core names. A core name abstracts a registrar, providing a means of correlating domains serviced by a core between the Oracle Communications Core Session Manager and the SLRM.
    • Cluster membership—All Oracle Communications Core Session Managers reside within a default cluster (null). The user can configure specific cluster membership to establish geographic-based preferences with which the SLRM can restrict traffic unless and until outages require that the infrastructure route that traffic outside of the preferred geography.
    • Number of current endpoints—An Oracle Communications Core Session Manager's known number of endpoints includes registered and unregistered users within the registration cache.
    • Maximum endpoint capacity—The Oracle Communications Core Session Manager determines maximum endpoint capacity dynamically. It uses the current number of endpoints and the resources in use by those endpoints to determine maximum endpoint capacity. The SLRM uses this number as part of its criteria to establish load balance order.
    • Operational resources available—The Oracle Communications Core Session Manager also tracks current CPU and memory utilization.
  • Manages cluster membership via refresh timing.
  • Manages SLRM core registration via refresh timing.
  • Responds to SLRM-initiated rebalance processes.
  • Supports manual rebalance processes from the Oracle Communications Core Session Manager.
  • Maintains connectivity with the SLRM function via watchdog messaging

The user specifies registrars for load balancing on an Oracle Communications Core Session Manager using a registrar's (ims-core) parameter, which aligns with a core name configured on the SLRM. These configurations establish 'load-balance group' names between Oracle Communications Core Session Managers and SLRMs.

Having determined core membership, the SLRM determines a target Oracle Communications Core Session Manager by evaluating the endpoint capacity information provided by the Oracle Communications Core Session Managers and identifying the best target for the traffic.