CISCO-SESS-BORDER-CTRLR-EVENT-MIB
The main purpose of this MIB is to define the SNMP notifications and alarms generated by Session Border Controller application and used to send these notifications to SNMP manager application. Each of these event/notification is explained in detail in the MIB file. The SBC service is implemented on a service card on CISCO routers. SBC application offer functionalities like firewall/NAT traversal, media bridging, policy-based call routing, signaling protocol inter-working, call billing and some degree of Call Admission Control. SBC looks to play an essential role in full-scale commercial deployment of VoIP and integration into the existing PSTN. 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. Various types of notifications required for SBC applications are as follows: 1. When SIP/H2.48 calls are established and SBC application receives traffic (RTP/RTCP packets) from a source whose IP address or port is ambiguous, a source alert event is generated for the unwanted data packets received by SBC application. 2. Blacklisting is the process of matching inbound packets based on some simple parameters (for example source IP address) and preventing packets that match those parameters from being processed. SBC detects an attempt to disrupt traffic flowing through it. When a source is blacklisted in SBC application, an event is generated to provide information of the blacklisted source like its IP address, port, VPN address etc. 3. When there is a change in the state of any SBC service configured like a new SBC service is configured or the SBC card goes to standby state, reboot or offline state, a service is removed from SBC card, an event is generated by SBC. 4. When a large number of SIP/H.248 calls are ongoing and system is congested i.e. high CPU usage or high use of memory utilization, congestion event is generated at this point and when congestion is cleared means CPU usage comes to normal another event for congestion clear is generated. 5. When a service is configured on SBC application, its call policies are defined during the configuration like maximum number of calls, maximum call rates etc. If any of these policies is violated, an event for violation of service level agreement is generated. 6. When a radius server is attached/detached with SBC, a notification is generated to provide information of radius server type, IP address, port etc. 7. When an adjacency is attached/detached with SBC, a notification is generated to provide its information like the adjacency type and state. 8. When a H.248 controller is attached/detached with SBC to establish H.248 calls with SBC, a notification is generated to provide the information regarding the attached/detached H.248 controller like controller index, IP address, port, state etc. 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. SLA: Service Level Agreement - Service level agreement includes some call admission control policies which are defined during the SBC configurations like maximum number of calls, maximum call rates etc. Diameter Server: A Diameter Server is one that handles authentication, authorization and accounting requests for a particular realm. REFERENCES 1. CISCO Session Border Controller Documents and FAQ http://zed.cisco.com/confluence/display/SBC/SBC