Sniffing-based network monitoring

1. A method of monitoring a packet-switched network via which real-time data is transmitted, the method comprising:

in response to signaling messages issued by a media gateway controller, non-promiscuously sniffing only data packets of a Voice over Internet Protocol (VoIP) phone call, said data packets containing real-time data, said non-promiscuous sniffing conducted by a monitor subagent to monitor a quality-of-service parameter, said monitor subagent accepting commands from a softswitch to start and stop the non-promiscuous sniffing such that unnecessary non-promiscuous sniffing in an absence of Real-Time Transport Protocol (RTP) traffic does not occur, wherein the sniffing is with regard to at least one of RTP packets and RTP Control Packets (RTCP), wherein said real-time data is encapsulated with a Real-Time Transport Protocol (RTP) header and a Real-Time Transport Protocol (RTP) trailer and said Real-Time Transport Protocol (RTP) header and said Real-Time Transport Protocol (RTP) trailer are encapsulated with a user datagram protocol (UDP) header and a user datagram protocol (UDP) trailer;

notifying, in response to a threshold breach of the quality-of-service parameter detected via said non-promiscuous sniffing, a monitor agent about the threshold breach;

forwarding to the media gateway controller the threshold breach of the quality-of-service parameter, the media gateway controller then adapting to changed network conditions indicated by the quality-of-service parameter by directing media entities to renegotiate bandwidth communication for a higher bandwidth communication for the VoIP phone call;

notifying, by the monitor agent, a network node manager about the threshold breach, wherein the network node manager is a hardware entity comprising computer code stored thereon; and

determining, by the network node manager via responsive initiation and performance of a path analysis, a root cause of a fault of the threshold breach.

2. The method of claim 1 , wherein the determining of the root cause of the fault enables Service Level Agreement (SLA) management.

3. The method of claim 1 , further comprising reporting the root cause to a user.

4. The method of claim 1 , wherein the quality-of-service parameter comprises one of egress delay, ingress delay, jitter, roundtrip delay, packet loss, throughput, instantaneous signal loss, and accumulated content loss.

5. The method of claim 1 , wherein notifying a network node manager comprises sending a trap to the network node manager.

6. The method of claim 5 , wherein sending a trap comprises sending a simple network management protocol (SNMP)-trap.

7. The method of claim 1 , wherein the path analysis comprises examining interfaces of network devices lying on a path.

8. The method of claim 1 , wherein the monitor subagent cooperates with determining the root cause of the fault.

9. The method of claim 1 , wherein the network node manager comprises a path analysis subsystem and a root cause analysis subsystem.

10. The method of claim 1 , wherein an alert is triggered in response to breaching a threshold.

11. The method of claim 1 , wherein a “what-if” analysis is performed based on performance data stored in a data warehouse.

12. A system for monitoring a packet-switched network via which real-time data is transmitted, the system comprising:

one or more monitor subagents configured to:

in response to signaling messages issued by a media gateway controller, non-promiscuously sniff only data packets of a Voice over Internet Protocol (VoIP) phone call, said data packets containing real-time data to monitor a quality-of-service parameter, said monitor subagent accepting commands from a softswitch to start and stop the non-promiscuous sniffing such that unnecessary non-promiscuous sniffing in an absence of Real-Time Transport Protocol (RTP) traffic does not occur, wherein the sniffing is with regard to at least one of (RTP) RTP packets and RTP control packets (RTCP), wherein said real-time data is encapsulated with a Real-Time Transport Protocol (RTP) header and a Real-Time Transport Protocol (RTP) trailer and said Real-Time Transport Protocol (RTP) header and said Real-Time Transport Protocol (RTP) trailer are encapsulated with a user datagram protocol (UDP) header and a user datagram protocol (UDP) trailer;

notify, in response to a threshold breach of the quality-of-service parameter detected via said non-promiscuous sniffing, a monitor agent about the threshold breach;

forward to the media gateway controller the threshold breach of the quality-of-service parameter, the media gateway controller then adapting to changed network conditions indicated by the quality-of-service parameter by directing media entities to renegotiate bandwidth communication for a higher bandwidth communication for the VoIP phone call; and

the monitor agent configured to notify a network node manager about the threshold breach, wherein the network node manager is a hardware entity comprising computer code stored thereon that, when executed by a processor, causes the network node manager to responsively initiate and perform a path analysis to determine a root cause of a fault of the threshold breach.

13. The system of claim 12 , wherein the network node manager is configured to determine the root cause of the fault by performing a path analysis to find out a path over which real-time data is transmitted.

14. A non-transitory computer-readable storage medium having stored thereon, computer-executable instructions that, when executed by a system, causes the system to perform a method comprising:

in response to signaling messages issued by a media gateway controller, non-promiscuously sniffing only data packets of a Voice over Internet Protocol (VoIP) phone call, said data packets containing real-time data, said non-promiscuous sniffing conducted by a monitor subagent to monitor a quality-of-service parameter, said monitor subagent accepting commands from a softswitch to start and stop the non-promiscuous sniffing such that unnecessary non-promiscuous sniffing in an absence of Real-Time Transport Protocol (RTP) traffic does not occur, wherein the sniffing is with regard to at least one of RTP packets and RTP control packets (RTCP), wherein said real-time data is encapsulated with a Real-Time Transport Protocol (RTP) header and a Real-Time Transport Protocol (RTP) trailer and said Real-Time Transport Protocol (RTP) header and said Real-Time Transport Protocol (RTP) trailer are encapsulated with a user datagram protocol (UDP) header and a user datagram protocol (UDP) trailer;

notifying, in response to a threshold breach of the quality-of-service parameter detected via said non-promiscuous sniffing, a monitor agent about the threshold breach;

forwarding to the media gateway controller the threshold breach of the quality-of-service parameter, the media gateway controller then adapting to changed network conditions indicated by the quality-of-service parameter by directing media entities to renegotiate bandwidth communication for a higher bandwidth communication for the VoIP phone call;

notifying, by the monitor agent, a network node manager about the threshold breach, wherein the network node manager is a hardware entity; and

determining, by the network node manager via responsive initiation and performance of a path analysis, a root cause of a fault of the threshold breach.

15. The computer-readable storage medium of claim 14 , wherein determining the root cause of the fault comprises performing a path analysis to find out a path over which real-time data is transmitted.