3com Corporation

Asc - Advanced Switching Communications

Stanley T Naudus

Vijay J Nadkarni

Guido M Schuster

Chester Szczepucha

Thomas A Gentles

Daniel L Schoo

James M Kroll

Leland Otis Thompson

William Verthein

Ying Wu

Richard J Varman

Jack L Manbeck, Jr

Tom Gentles

Chang-Shan Hsu

D Richard Miller, Jr

James R Loehndorf, Jr

Disclosed is an architecture for a network access server wherein a switching device is placed between a network gateway device and a first network, where the switching device detects the presence or absence of a security protocol field in the header information of data packets received from the first network and routes the data packets accordingly. When the security protocol field is absent, the switching device routes the data packet to the network gateway device for processing in accordance with a protocol service provided by the network access server. When the security protocol field is present, the switching device decrypts the data packet, processes the data packet in accordance with the protocol service provided by the network access server, and routes the data packet to another device within the network access server on the basis of decrypted address information within the data packet.

Apparatus and method for processing encrypted packets in a computer network device

Method and apparatus for Real Time protocol mixer traversal. Data including at least one feedback component are transmitted from a first to a second node. The feedback component is transmitted to the first node. Alternatively, a method includes transmitting Real Time Protocol data to a mixer from a first and a second node participating in a real time communications session. The mixer has a first feedback decoupling and a second feedback decoupling array. A feedback stream is sent from the first node and the second node to the mixer. The first and second feedback stream are responsive to the mixed stream. The first and second feedback stream are separated into a first and a second feedback component part. The first part is associated with Real Time Protocol information received from the first node. The second feedback component is representative of the information received from the second node. The first and second feedback component parts are combined into a plurality of feedback streams comprising the feedback components. The mixer feedback streams are transmitted to the nodes. A communications system includes a first and a second node. Data is transmitted from the first to the second node. A mixer receives feedback including at least one feedback component. The feedback component is transmitted to the first node and is responsive to the real time data received by the second node.

Method and apparatus for real time protocol feedback mixer traversal

A method and apparatus are used in a gateway to discard selected frames received with a selected encoded-information-type from a communication link with a larger bandwidth to avoid overflowing an internal delay variance removing queue used for protocol translation to a communication link with a smaller bandwidth. The discarded frames do not decrease the quality of translated information. A visual delay variance removing queue congestion indicator is included to indicate three levels of congestion in the delay variance removing queue for received frames. The method and apparatus are used in a multimedia gateway which is translating audio/video conferencing protocols (e.g., H.320, H.323/LAN H.323/PPP and H.324) received from a communication link with a large bandwidth and sent to a communication link with a smaller bandwidth.

Method and apparatus for adaptive prioritization of multiple information types in highly congested communication devices

A system and method in a network-based telephone system for simulating a typical plain old telephone system (POTS) connection by generating sounds in response to conditions in the telephone connection that simulate POTS sounds that occur during the typical POTS connection. Telephones in a network-based telephone system are connected to a wide-area network (WAN) such as the Internet via an Internet telephony gateway. A calling telephone connects to the local exchange carrier to permit a user to connect to a calling Internet telephony gateway by dialing an access telephone number. The calling Internet telephony gateway receives access information and the destination telephone number and uses the destination telephone number to determine the Internet telephony gateway that is closest to the called telephone with the destination telephone number. The calling Internet telephony gateway connects to the called Internet telephony gateway which connects to the called telephone number. During the setup of the connection, the calling Internet telephony gateway generates dialing sounds to the calling telephone. The Internet telephony gateway may also generate busy signals, fast busy signals, click sounds and comfort noise sounds to provide the caller with a POTS feel.

System and method for simulating telephone use in a network telephone system

A method and apparatus for sending delay sensitive information assisted by packet switched networks for network nodes in a computer network. Delay sensitive information such as voice information is sent over higher cost delay sensitive connections. Control and status information for the delay sensitive connections is sent in control messages over lower cost packet switched connections to the nodes in the computer network. Information in the control messages is stored in status tables on the network nodes. The status table is used by network nodes to determine the status of any delay sensitive connections in the computer network and is used to establish a lowest cost connection path or a desired quality of service connection path when a delay sensitive connection between network nodes is requested. Sending delay sensitive control and status information over the lower cost packet switch connections to the network nodes and using status tables on the network nodes to establish delay sensitive connections significantly decreases the costs associated with using delay sensitive connections.

Method and apparatus for sending delay sensitive information assisted by packet switched networks

A method and apparatus for communicating packet fragments over a symmetrical interface with reversed asymmetrical links. The method comprises the steps of coupling a first asymmetric interface to a computing device. The first interface has an up-link transmission rate greater than its down-link receiving rate. A second asymmetric interface is coupled to the computing device. The second interface has a down-link rate and an up-link rate. The down-link rate is greater than the up-link rate, the difference between the two rates defining a second asymmetric difference that is substantially equal to the first asymmetric difference. The apparatus comprises a first asymmetric interface having an up-link rate and a down-link rate. The down-link rate is less than the up-link rate wherein a difference between the up-link rate and the down-link rate defines a first asymmetric difference. A second asymmetric interface has a down-link rate and an up-link rate. The up-link rate is less than the down-link rate wherein a difference between the down-link rate and the up-link rate defines a second asymmetric difference that is generally equivalent to the first asymmetric difference.

Multiple parallel asymmetric interfaces with reversed asymmetric links

A method and apparatus for distributing protocol processing among a plurality of computing platforms. Data communications equipment such as Remote Access Devices, Communication Servers, Terminal Servers, and Dial-up Routers provide single user or large-scale multiple user communication access to various computing environments. The equipment costs and performance of such access equipment is related to the amount of CPU processing capability and memory required to support the desired number of serial communication links. It is common to use protocols that terminate in their entirely in the same processing machine. This invention encompasses methods developed to increase the cost/performance capabilities of the communication equipment that supports these serial links, primarily by means of distributing the protocol processing for higher level protocols across multiple computing platforms, including devices such as modems. Examples of such higher level protocols include PPP, SLIP and RTP.

Distributed processing of high level protocols, in a network access server

A method and system for reflexive tunneling. One aspect of the invention includes a method for reflexive tunneling using hidden virtual tunnels. A first peer application sends data packets to a second peer application and intermediate network devices create a hidden virtual tunnel to send the data packets. The hidden virtual tunnel is &ldquo;hidden&rdquo; from the first peer application and the second peer application. The hidden virtual tunnels may allow supplemental services to be added to a network device such as a gateway in less time with less expense. Another aspect of the invention includes a method for reflexive tunneling using transparent virtual tunnels with multiple segments. A first peer application associated with a first network device on a first network with multiple communication channels sends data packets to a second peer application associated with a second network device on a second network over a pre-determined communications channel forming a first segment of transparent virtual tunnel. Intermediate network devices create a second segment of the transparent virtual tunnel, by adding headers to the data packets between the first and second networks. Reflexive tunneling with transparent virtual tunnels with multiple segments between the first and second networks, may allow peer applications on a network device with multiple communication channels on a communication link to communicate with other peer applications on other independent devices without confusion.

Method and system for reflexive tunneling

A method and system in a network telephony system for transporting audio signals with lower delay when DTMF is not present. The method of transporting audio signals determines whether DTMF signals are included in the audio signal, or are likely to be transported according to the called or calling parties. A delay is imposed in the audio when DTMF signals are sensed or determined to be present as indicated by the calling party, the destination telephone number, the called party, and various other indicators. A timer may be used to trigger a reduction and elimination in the audio delay after an initial period in the call for calls in which DTMF signaling is used for an initial period of the call. The timer may also trigger the reduction and elimination in the audio delay when no DTMF signals have been received after a period of time. The system uses a DTMF detector to sense DTMF signals in the audio signal and to signal the delay generator to impose a delay in the audio stream. The delay generator may impose the delay by elongating the time between talk-spurts or by inserting fill packets in the audio stream. The delay may be removed from the audio stream when DTMF is not likely to be present.

System and method for efficiently transporting dual-tone multi-frequency/multiple frequency (DTMF/MF) tones in a telephone connection on a network-based telephone system

A protocol and method for synchronized transfer-window based firewall traversal is provided. The firewall traversal protocol includes messages for securely opening and closing a virtual data transfer-window through a firewall. The method allows a first network device inside a firewall to allow a virtual data transfer-window through a firewall to be opened with a second network device outside the firewall by sending the second network device secure information with the firewall traversal protocol. The secure information allows the second network device outside the firewall to securely traverse the firewall through the virtual data transfer-window to reach the first network device inside the firewall. The protocol and method help to improve firewall security and may help make the firewall less vulnerable to a number of common firewall attacks.

Method and protocol for synchronized transfer-window based firewall traversal

Method and apparatus for adaptive prioritization of multiple information

A method and apparatus for determining a network protocol type as the protocol is received on a network connection is presented. A network protocol being used on a communication link is determined by receiving N-number of data frames over the communication link, where N is a small number (e.g., 1 data frame). Error detection codes are calculated on the N-number of data frames with a selected error detection process. The calculated error detection codes are used to determine the type network protocol being used on the communication link. A protocol stack with multiple network protocol layers used on a communication link can also be determined by identifying individual protocol types in the protocol stack using error detection codes. Identifying a network protocol as it is received reduces the complexity of identifying network protocols and prevents multiple network protocol interpreters from being invoked to determine what network protocol is being used.

Method and apparatus for determining a protocol type on a network

A system is provided for creating a tunneling service from the use of a traditional tunneling protocol, such as the layer two tunneling protocol (L2TP). In particular, the L2TP tunneling protocol, which is designed to go point-to-point between an L2TP Access Concentrator (LAC) and an L2TP Network Server (LNS), is abstracted so that L2TP becomes an access protocol to a tunneling service. A new L2TP tunnel merger and management (LTM) service is created which severs the tight configuration relationships between LAC and LNSs. Only a tight configuration between an LAC and its LTM edge device and between an LNS and its LTM edge device is required. An internal trunk protocol (INT protocol) carries needed information between LTM edge devices to establish ingress/egress L2TP access calls inside of separate L2TP access tunnels on opposite LTM edge devices. The addition of another LAC is accomplished by re-routing L2TP tunnels within the LTM service without reconfiguration of the LNSs, and the addition of another LNS is accomplished by re-routing L2TP tunnels within the LTM service without reconfiguration of the LACs. The LTM service determines the need for both additional trunk and access resources and establishes both new trunk/access tunnels to provide additional resources. The LTM service also determines excess resources on both trunk and access entities and releases trunk/access tunnels to provide the needed additional resources.

Growing community of inventors

Springfield, VA, United States of America

Stanley T Naudus