Cisco Technology, Inc.

Andrew J Valencia

Kenneth A Moberg

Claude Alan Cartee

Pradeep Kumar Kathail

William B May, Jr

Kirk Stewart Lougheed

Pedro Marques

David R Hampton

Timothy D Kolar

Gregory D Stovall

Shoou Jiah Yiu

Carl D Sutton

Chandrashekhar Appanna

Andrew George Harvey

Frederick Juergens Baker

Joel P Bion

Ashwin Baindur

Pokman Perry Leung

A layer two forwarding protocol (L2F) provides virtual direct dial-up service into private networks through public internet service providers. An authorized remote client appears as a direct dial-up client to the home gateway, even through the client is accessing the home gateway remotely through the ISP. The new forwarding protocol allows the remote client to conduct point-to-point link protocols, such as point-to-point protocol (PPP) and serial line interface protocol (SLIP) directly with the local network home gateway. The network access server changes from a routing mode where a communication protocol is conducted with the client to a switching mode where the POP simply sends data from one port to a tunnel. The tunnel then transmits the data to another port, regardless of the header information on transmitted data packets. The remote client can then be managed through databases controlled by the local network and gain access to resources not typically accessible through the internet. The layer two forwarding protocol conducts an independent authorization session to prevent unauthorized access to the private network and provides point-to-point protocol transport over the internet independently of internet transport protocols.

Virtual dial-up protocol for network communication

In an embodiment, a network router includes plural interfaces and a chain walker which, upon receipt of a first protocol packet in a first interface, processes the packet by walking the packet through a decapsulation chain associated with the interface and the first protocol and an encapsulation chain associated with an identified second interface and identified second protocol. The walker passes the packet to elements of the decapsulation chain to produce a decapsulated packet. The walker passes the decapsulated packet to elements of an encapsulation chain to produce an encapsulated packet. Each chain includes at least one packet-processing element. An element receives the packet from the walker as processed by a previous element, the packet being further processed as appropriate. The walker, upon receipt of the first protocol packet, passes the packet to elements of a demultiplexer chain associated with the first interface to produce a demultiplexed packet.

Packet processing using encapsulation and decapsulation chains

A system and method are disclosed for increasing the efficiency with which data is transmitted over a network link. Voice packets are encoded to include header bits that indicate the presence and duration of pauses in the voice transmission. A Network linking device monitors incoming voice packets on a link, checking for the presence of a pause. The linking device also keeps track of all voice connections on the link. When none of the voice connections are active, the linking device increases the size of the maximum allowed transferable unit (MATU), thus fragmenting less data packets than it would have fragmented if a voice connection had been active. Fragmentation is reduced while maintaining sound quality.

Optimizing queuing of voice packet flows in a network

A method and system for notifying router subsystems of configuration changes made to router configuration information which are maintained by a centralized information provider or database system. The centralized database provides registration and unregistration for notification of changes made to the router configuration information. The centralized database further provides router configuration change notifications to subsystems registered to receive such notifications.

Subsystem application notification method in a centralized router database

A method for processing packets in a router includes specifying operations on packets as chains of processing elements. Each chain is uniquely associated with one interface/protocol pair, and each processing element performs at least one function on a packet. An incoming packet is received, and processed, first by a demultiplexor element which determines the protocol of the next higher level used by the packet. Then, the packet is processed by the elements of a decapsulation chain associated with the interface on which the packet was received, and by the elements of an encapsulation chain associated with the interface on which the packet is to be transmitted. The demultiplexor element or operation passes the packet on to a decapsulation chain associated with the protocol and with the incoming interface, depending on protocol information contained in the incoming packet. Decapsulation and encapsulation chains can be built dynamically, by inserting new and removing old elements as necessary as new protocols are developed and new features added. A chain walker walks through the chains, passing the processed packet to each element in a chain, until either the end of the chain is reached and processing is complete, or until the packet is dropped because no function can process it, or because a packet is processed by an outside process or by hardware, which may optionally stop the chain walk. A chain walk may be temporarily halted, or may be terminated. If temporarily halted, the chain walk can be resumed at any element in the chain, depending on the packet's requirements. A chain walk can also begin at any element in a chain.

A method and system for verifying router configuration transactions carried out by a centralized information provider or database system. The centralized database provides verification registration and verification unregistration for various router subsystems associated with said database system. The centralized database and the subsystems registered for verification engage in a verification handler sequence to verify proposed router configuration transactions.

Method and system for verifying configuration transactions managed by a centralized database

A method and system for transacting routing device configurations using a centralized information provider or database system. The invention receives configuration commands from a user of the router. The invention then communicates the configuration command to the centralized database system. The centralized database system manages a storage structure (database tree) having a plurality of tuple nodes, where each tuple node contains configuration data for the router. The centralized database then carries out the configuration change in the appropriate tuple node using the configuration information provided in the configuration command issued by the user. The invention allows the user of the router to &ldquo;back-out&rdquo; of such transactions by reverting the configuration of the affected tuple node to its previous or original state. The invention also reverts the configuration of the affected tuple nodes upon the occurrence of certain events.

Method and system for executing, tracking and restoring temporary router configuration change using a centralized database

A method of monitoring congestion within a data path having a queuing node located therein and a plurality of downstream nodes positioned downstream of the queuing node. The method includes monitoring congestion at the plurality of downstream nodes and setting a congestion notification flag by one of the downstream nodes when the node is congested. The transmission of data packets from the queuing node is stopped and packets received at the queuing node are queued when the flag is set. The method further includes transmitting packets from the queuing node when the congestion notification flag is cleared. A system for monitoring congestion on a data path is also disclosed.

Congestion management system and method

A layer two forwarding protocol (L,F) provides virtual direct dial-up service into private networks through public internet service providers. An authorized remote client appears as a direct dial-up client to the home gateway, even through the client is accessing the home gateway remotely through the ISP. The new forwarding protocol allows the remote client to conduct point-to-point link protocols, such as point-to-point protocol (PPP) and serial line interface protocol (SLIP) directly with the local network home gateway. The network access server changes from a routing mode where a communication protocol is conducted with the client to a switching mode where the POP simply sends data from one port to a tunnel. The tunnel then transmits the data to another port, regardless of the header information on transmitted data packets. The remote client can then be managed through databases controlled by the local network and gain access to resources not typically accessible through the internet. The layer two forwarding protocol conducts an independent authorization session to prevent unauthorized access to the private network and provides point-to-point protocol transport over the internet independently of internet transport protocols.

A stack group bidding protocol (SGBP) establishes systems as members of a stack group connected together through one or more networks. When an event, such as establishment of a point-to-point link, occurs on one of the systems, a bid request is sent to each stack group member. Each stack group member then bids for the event. The bid is based on dynamic bid weighting criteria that varies depending on the computation capacity of the member at the time the bid request is initiated. A multichassis multilink PPP (MLP) protocol utilizes the SGBP to conduct multilink PPP sessions for links that either originate or terminate on different physical systems. A L2F forwarding protocol is used in combination with multichassis MLP to forward the links from one system to another system and offers location transparency.

Growing community of inventors

Vashon, WA, United States of America

Andrew J Valencia