Sonus Networks, Inc.

Wassim Matragi

Ahmed Abdelal

David Lapsley

Ti-yuan Dean Shu

Joby Joseph

Mark Topham

Kenneth Dumble

Sri Chary

Jonathan Klotzbach

Miri Mansur

Shaun Jaikarran Bharrat

James A Pasco-Anderson

Oliver C Ibe

Ronald V Grippo

Fardad Farahmand

Vladimir Botchev

Kenneth R St Hilaire

Nui Chan

Rohinton Gonda

Sunil K Menon

Glenn W Stewart

William C Templeton

The invention features systems and methods for detecting and mitigating network attacks in a Voice-Over-IP (VoIP) network. A server is configured to receive information related to a mitigation action for a call. The information can include a complexity level for administering an audio challenge-response test to the call and an identification of the call. The server also generates i) a routing label based on the identification of the call, and ii) a script defining a plurality of variables that store identifications of a plurality of altered sound files for the audio challenge-response test. Each altered sound file is randomly selected by the server subject to one or more constraints associated with the complexity level. The server is further configured to transmit the script to a guardian module and the routing label to a gateway.

Real-time network attack detection and mitigation infrastructure

A non-intrusive objective speech quality assessment is performed on a degraded speech signal. The methods are well suited for systems where random and bursty packet losses may occur and/or packet stream regeneration may also occur prior to speech signal quality assessment. In one embodiment received packetized speech is analyzed to determine to an overall final signal quality score. A limited set of trained neural networks, e.g., 5, corresponding to different signal features, each determine a signal feature quality score. A trained joint quality score determination module determines a joint quality score based on the signal feature quality scores. Packet loss is estimated based on received packet header information and/or detected gap durations. The determined joint quality score is adjusted, based on estimated packet loss information obtained from examining the speech signal, network level statistics and/or codec parameters to generate the final quality score.

Methods and apparatus for signal quality analysis

Described are methods and apparatuses, including computer program products, for limiting server overload via client control. A first set of a plurality of requests are transmitted to a server at a first transmission rate during a first period of time. The first transmission rate is limited to be less than or equal to a first transmission limit rate. An overload value is determined based on whether at least two or more requests of the first set of requests for service satisfy an overload criterion. A second transmission limit rate is determined based on the overload value and the first transmission limit rate. A second set of a plurality of requests is transmitted to the server at a second transmission rate during a second period of time. The second transmission rate is limited to be less than or equal to the second transmission limit rate.

Adaptive rate control based on overload signals

Described are methods and apparatuses, including computer program products, for controlling server resources. An occupancy value of a buffer and a first utilization value of a first processor are measured. The buffer is configured to store one or more requests for service from at least a first client. The first processor is configured to receive and process the one or more requests from the buffer. A buffer size value is determined based on a processor throughput calculation, and a first service request limit for the first client is determined based on the occupancy value, the first utilization value, and the buffer size value.

Hybrid server overload control scheme for maximizing server throughput

Described are methods and apparatus, including computer program products, for controlling time-sensitive data in a packet-based network. Data associated with a call is received, and the data includes an identifier associated with the data, a data source, or one or more data destinations. The data is associated with a logical trunk group selected from a plurality of logical trunk groups each in communication with the one or more data destinations over a packet-based network. The logical trunk group is selected based in part on the identifier. Calls through the packet-based network are managed based in part on the associated logical trunk group.

Controlling time-sensitive data in a packet-based network

Growing community of inventors

North Andover, MA, United States of America

Wassim Matragi