Cisco Technology, Inc.

Diasense, Inc.

Mark L Hendrickson

Jonathan David Rosenberg

Cullen F Jennings

Hakim N Mehmood

Rajeev Narang

Rajiv Asati

Stewart Frederick Bryant

John K Restrick, Jr

Christian Cassar

John D Alexander

Chris Pearce

Augustyn Waczynski

Somashekar S V

David J Hartwick

Andre V Vaguine

Subramanian Thamaraisamy

David E Hanzel

Kenneth A Patton

A method is provided in which a call agent process that supports one or more Internet Protocol (IP) calls, stores to persistent memory a set of data associated with the one or more IP calls. An outage is detected affecting the one or more IP calls. Using the data retrieved from the persistent memory, the one or more IP calls are resynthesized using a device simulator process to simulate connectivity with endpoints that were participating in the one or more IP calls prior to the outage. After resynthesizing, depending on activity detected from devices associated with the one or more IP calls, the one or more IP calls are internally re-stitched/re-establishing (without signaling to endpoints) with the endpoints involved in the one or more IP calls, or the one or more calls are fully re-stitched/re-established by signaling an endpoint that was participating in the one or more IP calls.

Supporting hitless upgrade of call processing nodes in cloud-hosted telephony system

In one embodiment, a network interruption may be determined to have occurred at an active node of a communication system, wherein the active node may be facilitating a first communication dialog between a first end point and a second end point. In response to the network interruption, a stateful switchover can be initiated between the active node and a standby node of the communication system. A reroute message may be transmitted to the first end point and the second end point, wherein the reroute message can instruct the first end point and the second end point to cease use of the first communication dialog and begin use of a second communication dialog, wherein the second communication dialog may be facilitated by the standby node.

Method and apparatus for supporting high availability

In one embodiment, a clock on a network device is initialized, and then a first timing message is received at the network device from a reference device having a first timestamp indicating when the first timing message was transmitted from the reference device. The network device may then determine and store a one-way delay from the first timestamp to a first time at which the first timing message was received at the network device. In response to restarting the clock, the network device may receive a second timing message from the reference device having a second timestamp indicating when the second timing message was transmitted from the reference device. The network device may then calibrate the clock such that a second time at which the network device received the second timing message is the second timestamp plus the stored one-way delay.

Recalibration of precision clocks in a computer network

A system may generate from a first value, based on rounding information, a first security key that matches a second security key whenever the first value and a second value from which the second security key is generated differ by less than a non-zero predetermined amount. The second security key may be generated from the second value rounded to a multiple of a rounding interval that is nearest to the second value. The rounding information may include a rounding direction indication. The rounding direction indication may indicate the direction in which the second value is rounded to the multiple of the rounding interval nearest to the second value.

Rounding for security

A system for verifying VoIP call routing information. The system may include an apparatus integrated with a private branch exchange (PBX). The apparatus may store at least one call attribute of a public switched telephone network (PSTN) call initiated to a destination telephone number. The apparatus may verify a destination Voice-over-Internet-Protocol (VoIP) call agent for the destination telephone number based on demonstrated knowledge of the PSTN call. The apparatus may route a new call either over a VoIP network to the destination VoIP call agent or over a circuit switched network based on whether the destination VoIP call agent is verified for the destination telephone number.

Integration of VoIP address discovery with PBXs

In one embodiment, an apparatus may receive at least one call attribute of a public switched telephone network (PSTN) call initiated to a destination telephone number. The apparatus may verify a destination Voice-over-Internet-Protocol (VoIP) call agent for the destination telephone number based on demonstrated knowledge of the PSTN call. The apparatus may transmit an indication the destination VoIP call agent is verified for the destination telephone number.

Separation of validation services in VoIP address discovery system

Synchronous detection system for multichannel infrared spectroscopy

Growing community of inventors

Lafayette, CO, United States of America

Mark L Hendrickson