1. Essentials Guide
  2. Oracle USM Supporting the IMS Edge
  3. Access Border Functions
  4. A-BGF Functions

A-BGF Functions

The Oracle Communications Unified Session Manager performs the following access-related BGF functions:

  • Opening and closing gates/packet filtering—The Oracle Communications Unified Session Manager opens and closes gates (media pinholes) on a session-by-session basis. Packet filtering rules include full source and destination IP address and port number.
  • Per-session DiffServ or ToS marking—Media flows destined for the IMS core network can be explicitly marked using ToS or DiffServ. Media packets can be marked by VPN, by codec (voice, video) or by E.164 phone number prefix.
  • NAPT-PT and topology hiding—The Oracle Communications Unified Session Manager provides NAPT for all media flows associated with a session on a per session-basis. Double NATing, NATing both source and destination sides, is utilized to fully hide topology in each direction for RTP and RTCP. Local IP addresses and port resources are dynamically allocated from steering pools provisioned on the Oracle Communications Unified Session Manager.
  • Hosted NAT traversal—The Oracle Communications Unified Session Manager supports HNT function that allows media flow traversal through the CPE firewall/NAT without upgrading the CPE equipment. The Oracle USM interacts with the endpoints to dynamically establish and maintain bindings in the CPE firewall/NAT that allow the signaled communications to pass through. The Oracle Communications Unified Session Manager's registration management and media relay functions make CPE-based NATs transparent to the service delivery elements.
  • Traffic Policing—Traffic is policed at the session and media/transport layer. At the signaling layer, the Oracle Communications Unified Session Manager polices at a number of levels.
  • Policing of Media (e.g. RTP & RTCP) traffic on a per-flow basis—CBR policing is applied to each flow based on offered and negotiated media codecs.