Patent ID: 8363555

Claim:
An apparatus comprising: an interface at an endpoint coupled to a network, the interface operable to receive signaling packets from the network, wherein the signaling packets comprise Layer 3 data or Layer 2 data, the Layer 3 data comprising Internet Protocol (IP) headers, the Layer 2 data indicating quality of service (QoS) classifications of the signaling packets; and a monitoring agent at the endpoint coupled to the interface, the monitoring agent operable to: compare one or more portions of the Layer 3 data or the Layer 2 data in the signaling packets with reference data residing at the endpoint prior to receipt of the signaling packets, the reference data comprising one or more portions of one or more proper IP headers or proper QoS classifications; determine whether one or more of the portions of the Layer 3 data or the Layer 2 data in the signaling packets deviate from the reference data residing at the endpoint; and if one or more of the portions of the Layer 3 data or the Layer 2 data in the signaling packets deviate from the reference data at the endpoint, then report to a call agent residing at a server coupled to the network the one or more deviations as one or more signaling-packet faults in the signaling packets, the signaling-packet faults in the signaling packets suggesting one or more network-path faults in a network path that communicated the signaling packets to the interface.