US 8248953

Patent Overview — US8248953B2

Title: Detecting and isolating domain specific faults

Patent number: US8248953B2 (application US11/782,906; publication US20090028054A1)

Assignee: Cisco Technology, Inc. (original and current assignee per the source listing)

Inventors: Rajesh Kumar; Randall P. J. Ethier

Key dates: Priority/filing date 2007-07-25; publication 2009-01-29; granted 2012-08-21; status listed Active with adjusted expiration 2028-12-05.

Purpose: The disclosure addresses communications quality impairments — e.g., low signal level, high noise level, low mean opinion score — which may be caused by packet loss, excessive traffic, endpoints out of sync, or incompatible hardware/software. Existing diagnostic services typically measure quality at the receiving end only, revealing end-to-end quality but not which network domain degraded the call.

Plain-language scope: The approach compares a first media quality report for a communication from a first node (an ingress node of a first domain) with a second media quality report from a second node (an egress node of that domain). If the difference in at least one aspect exceeds a first threshold, a path between the first and second node used by the communication is determined, and the source(s) causing the difference are isolated. A call quality monitoring system (CQMS) may receive, store, and compare metric reports from endpoints or nodes; metric reports may cover packet loss, delay, jitter, echo, signal level, noise level, failed connections, end-to-end delay, speech/silence, concealed seconds, and severely concealed seconds. An "edgepoint" (e.g., an RTP media relay or session border controller) may define a domain boundary. Stated advantages include identifying which entity within a domain degraded a communication, supporting per-stream SLA verification, and producing evidence that a domain was not the cause.

Source: https://patents.google.com/patent/[US8248953](/patent/US8248953)/en (fetched 2026-09-23).

What the excerpt does not establish: It does not provide the full claim text, the complete written description, the detailed description of FIG. 3's method steps, any prior-art references, or prosecution history. The excerpt is explicitly marked as partial ("consult the source for omitted text"), so claim scope and dependency cannot be fully stated. No litigation, ownership-transfer, validity, or prior-art analysis was performed.