The main purpose of this MIB is to define the statistics information for Session Border Controller application. The statistics are mainly of two types - Call statistics and Media statistics. The calls can further be categorized as SIP calls and H.248 calls.
This MIB categorizes the statistics information into following four types: 1. Global call statistics - Represents the global call related
statistics like call rates, media flows, signaling flows etc.
- Periodic statistics - Represents the SBC call statistics information for a particular time interval like current 5 minutes, previous 5 minutes, current 15 minutes, previous 15 minutes, current hour and previous hour.
- Per flow statistics - Represents the SBC media flow statistics. These are media statistics for each of the current ongoing call flow.
- H.248 statistics - Represents the H.248 call related statistics information when H.248 controller is associated with SBC.
The Session Border Controller (SBC) enables direct IP-to-IP interconnect between multiple administrative domains for session-based services providing protocol inter-working, security, and admission control and management. The SBC is a voice over IP (VoIP) device that sits on the border of a network and controls call admission to that network.
The primary purpose of an SBC is to protect the interior of the network from excessive call load and malicious traffic. Additional functions provided by the SBC include media bridging and billing services.
GLOSSARY SBC: Session Border Controller
CSB: CISCO Session Border Controller
CAC: Call Admission Control - protects voice traffic from the negative effects of other voice traffic and to keep excess voice traffic off the network. It is used to prevent congestion in Voice traffic. It is used in the Call Setup phase.
RTP: Real Time Transport Protocol - defines a standardized packet format for delivering audio and video over the Internet.
RTCP: Real Time Control Protocol - It is a sister protocol of the Real-time Transport Protocol (RTP). RTCP provides out-of-band control information for an RTP flow. It partners RTP in the delivery and packaging of multimedia data, but does not transport any data itself. It is used periodically to transmit control packets to participants in a streaming multimedia session.
VMG: Virtual Media Gateway - introduced to bridge between different transmission technologies and to add service to end-user connections. Its architecture separates control and connectivity functions into physically separate network layers.
VPN: Virtual Private Network - It is a communications network tunneled through another network, and dedicated for a specific network.
Gate Id - Context Identifiers assigned uniquely to a SIP/H.248 call flows.
Flow Pair Id: Stream Identifiers assigned uniquely to a SIP/H.248 call flows.
Adjacency: An adjacency contains the system information to be transmitted to next HOP.
REFERENCES 1. CISCO Session Border Controller Documents and FAQ http://zed.cisco.com/confluence/display/SBC/SBC