Overview

Realms are a logical distinction representing routes (or groups of routes) reachable by the Oracle® Enterprise Session Border Controller and what kinds of resources and special functions apply to those routes. Realms are used as a basis for determining ingress and egress associations to network interfaces, which can reside in different VPNs. The ingress realm is determined by the signaling interface on which traffic arrives. The egress realm is determined by the following:

• Routing policy—Where the egress realm is determined in the session agent configuration or external address of a SIP-NAT
• Realm-bridging—As applied in the SIP-NAT configuration and H.323 stack configurations
• Third-party routing/redirect (i.e., SIP redirect or H.323 LCF)

Realms also provide configuration support for denial of service (DoS)/access control list (ACL) functionality.

Realms can also be nested in order to form nested realm groups. Nested realms consist of separate realms that are arranged within a hierarchy to support network architectures that have separate backbone networks and VPNs for signaling and media. This chapter provides detailed information about nested realms after showing you how to configure realms on your Oracle® Enterprise Session Border Controller.