Abstract: A method and system for distributed network address translation with security features. The method and system allow Internet Protocol security protocol (“IPsec”) to be used with distributed network address translation. The distributed network address translation is accomplished with IPsec by mapping a local Internet Protocol (“IP”) address of a given local network device and a IPsec Security Parameter Index (“SPI”) associated with an inbound IPsec Security Association (“SA”) that terminates at the local network device. A router allocates locally unique security values that are used as the IPsec SPIs. A router used for distributed network address translation is used as a local certificate authority that may vouch for identities of local network devices, allowing local network devices to bind a public key to a security name space that combines a global IP address for the router with a set of locally unique port numbers used for distributed network address translation.

Abstract: A Medium Access Control (“MAC”) Layer protocol and a method for contention resolution using the protocol is provided for networks with multiple priority traffic. The protocol is used where a physical layer connected to a transmission medium uses a carrier modulation scheme with multiple frequencies. Stations on the network that desire access to the transmission medium use a carrier modulation scheme with multiple frequencies. Stations that desire access simultaneously transmit a single frequency selected at random from a set of physical layer frequencies during an open-contention-interval. At the same time, the stations listen to a combined frequency signal and analyzes it for frequency content. The station whose own frequency matches the highest frequency signal in the combined signal gains access to a transmission medium. In the event of a collision, a restricted-contention-interval is used only for the colliding stations.

Abstract: A method and system for distributed network address translation for mobile network devices. A mobile network device requests one or more locally-unique ports with a Port Allocation Protocol from a second network device on a first network to identify the first network device on the first network if the mobile first network device roams to a second external network. One or more default or ephemeral ports on the mobile network device are replaced with one or more locally-unique ports obtained with the Port Allocation Protocol. The one or more locally-unique ports allow distributed network address translation to be used with the mobile network device. A combination network address is created for the mobile network device with a locally unique port and an external network address for the first network to identify the mobile first network device if the mobile first network device roams to a second external network.

Abstract: A system for user-space packet modification, including a set of kernel code and a user-level application programming interface (API). The system facilitates creation of a special socket for passing packets between kernel space and user space. The system in turn facilitates creation and application of a packet filter associated with the socket, in order to trap incoming or outgoing packets being processed in the kernel at a designated point in a protocol stack. Once a packet is trapped, it is moved through the socket into user space, thereby at least temporarily preventing the protocol stack from further processing the packet. In user space, an application may operate on the packet, for instance, modifying aspects of the packet or deleting the packet altogether. The system in turn facilitates injection of a packet from user space into kernel space, and into a designated point in the protocol stack for desired stack processing.

Abstract: A method and apparatus are provided for reducing delivery time latency in data transferred between a packet data service network and mobile data device. The method includes the steps of detecting an indicia of bandwidth needed for information to be transferred from the packet data service network to the mobile data device, comparing an attribute of the indicia with a predetermined criteria and notifying a wireless interface controller servicing the wireless data device when the attribute of the data block exceeds the predetermined file criteria.

Abstract: A method and apparatus for controlling the transmission of real-time media signals over a data network based on a triggering event associated with a participating teleconference station. This triggering event may be the presence or absence of motion, the presence or absence of sound, or any of a variety of other events that preferably indicate the presence or absence of a person at the station. When no person is present at the station and/or when an appropriate triggering event occurs, remote teleconference participants will not transmit media signals over the network to the station, thereby conserving valuable network bandwidth and simulating a physically common meeting between people. In turn, when a person is present at the station and/or when another appropriate triggering event occurs, remote teleconference participants may start transmitting media signals over the network to the station.

Abstract: A system for Distibuted Network Address Translation (“DNAT”). DNAT is used with small office/home office (“SOHO”) networks or other legacy local networks that have multiple network devices using a common external network address to communicate with an external network. The system includes a port allocation protocol to allocate globally unique ports to network devices on a local network. Individual network devices on a SOHO networks replace local source ports with the globally unique ports. The globally unique ports are used in a combination network address with a common external network address such as an Internet Protocol (“IP”) address, to identify multiple network devices on a local network to an external network such as the Internet, an intranet, etc. DNAT helps overcome the large computation burdens encountered when network address translation is done by a router and helps extend the life of older versions IP using 32-bit addressing.

Abstract: A high-fidelity voice/audio communication system including a high-fidelity SLIC (HSLIC) device that combines traditional BORSCHT functionality with high fidelity sampling and compression techniques. The HSLIC preferably resides on a single plug-in line card contained within a multi-cards chassis. The line card includes an analog interface that connects to a two-wire subscriber line, a high fidelity codec for sampling the analog signal at a high resolution and converting high rate digital signals to an analog signal, a voice processing client running on a microprocessor and associated digital memory. The high fidelity codec preferably has a sample rate of at least twenty thousand samples per second, and no less that 250 quantization levels.

Abstract: A method and apparatus are described for providing data services to a mobile data device through a packet data service node system and a wireless data network. The method includes the steps of exchanging data between the mobile data device and packet data service node system at least partially through the wireless data network using a tunneling protocol, decoding the tunneling protocol within a programmers space of a general purpose computing platform of the packet data service node system, determining an identity of the user from the decoded tunneling protocol and providing at least some data services to the identified user based upon a predetermined services list associated with the identified user.

Abstract: A computationally simple yet powerful forward error correction code scheme for transmission of real-time media signals, such as digitized voice, video or audio, in a packet switched network such as the Internet. An encoder at the sending end derives p redundancy blocks from each group of a k payload blocks and concatenates the redundancy blocks, respectively, with payload blocks in the next group of k payload blocks. At the receiving end, a decoder may recover up to p missing packets in a group of k packets, provided with the p redundancy blocks carried by the next group of k packets. The invention thereby enables correction from the loss of multiple packets in a row, without significantly increasing the data rate or otherwise delaying transmission.

Abstract: A test system and method for providing a network simulator to simulate the packet delivery delay and loss dynamics of an network such as the Internet. The test system delays and drops packets delivered between host devices on the test system according to a trace profile of the actual network packet delivery dynamics. The trace profile is recorded using a network measurement system transmitting and measuring the delivery of packets on the network. The trace profile records the actual network packet delivery dynamics, which is utilized by the test system to simulate the network packet performance. Using the test system as a network simulator, developers of interactive network application can accurately develop and test the performance of interactive network applications under realistic network conditions.

Abstract: A method and protocol for Distributed Network Address Translation (“DNAT”) is provided. DNAT is used to overcome the limited address 32-bit address space used for versions of the Internet Protocol (“IP”). DNAT is used with small office or home office networks or other legacy local network that have multiple network devices using a common external network address to communicate with an external network. The protocol includes a port allocation protocol to allocate globally unique ports to network devices on a local computer network. The globally unique ports are used in a combination network address with a common external network address such as an IP address, to identify multiple network devices on a local network to an external network such as the Internet, an intranet, or a public switched telephone network.

Abstract: A protocol and methods for peer network device discovery is presented. The peer discovery protocol includes a peer discovery marker than can be used with an existing networking protocol such as Transmission Control Protocol (“TCP”) to discover peer network devices. The peer discovery protocol also includes a peer discovery table to record network addresses of peer network devices and their associated host network devices. The peer discovery method allows a first peer network device such as an edge router, to send out a peer discovery request with the peer discovery protocol to other peer network devices as the peer network device is sending data packets for a host network device. Once a second peer network device receives a peer discovery request, the second peer network device attempts to establish a two-way, peer-to-peer data-flow to the first peer network device that sent the peer discovery requests.

Abstract: A computationally simple yet powerful forward error correction code scheme for transmission of real-time media signals, such as digitized voice, video or audio, in a packet switched network, such as the Internet. For each window of k data packets, the invention generates and transmits at least one cross-wise parity packet taken as an index-shifted function over the k data packets. The invention thereby enables a receiving end to recover from packet loss.

Abstract: A computationally simple yet powerful forward error correction code scheme for transmission of real-time media signals, such as digitized voice, video or audio, in a packet switched network, such as the Internet. The invention appends to each of a series of payload packets a single forward error correction code that is defined by taking the XOR sum of a preceding specified number of payload packets. The invention thereby enables correction from the loss of multiple packets in a row, without significantly increasing the data rate or otherwise delaying transmission.

Abstract: A Medium Access Control (“MAC”) Layer protocol and a method for contention resolution using the protocol is provided for networks with multiple priority traffic. The protocol is used where a physical layer connected to a transmission medium uses a carrier modulation scheme with multiple frequencies. Stations on the network that desire access to the transmission medium use a carrier modulation scheme with multiple frequencies. Stations that desire access simultaneously transmit a single frequency selected at random from a set of physical layer frequencies during an open-contention-interval. At the same time, the stations listen to a combined frequency signal and analyzes it for frequency content. The station whose own frequency matches the highest frequency signal in the combined signal gains access to a transmission medium. In the event of a collision, a restricted-contention-interval is used only for the colliding stations.

Abstract: A method and apparatus for improving the speed and quality of end-to-end data or real-time media transmissions over an internet is disclosed. A media stream being transmitted to the internet is channel coded at the edge of the internet in order to free upstream bit rate for use in source coding the media. The channel coded media stream may then be decoded at a remote edge of the internet to recover lost packets.

Abstract: A method and apparatus for improving the speed and quality of end-to-end data or real-time media transmissions over an internet is disclosed. A data stream representing a media signal at a given level of compression is processed just before the data stream enters the internet. A less compressed data stream representing the same media signal is generated transmitted through the internet. Due to the lower level of compression, the underlying media signal is less sensitive to packet loss in the internet and, as a result, the media signal that arrives at the receiving end will tend to be more continuous and clear.

Abstract: A computationally simple yet powerful forward error correction code scheme for transmission of real-time media signals, such as digitized voice, video or audio, in a packet switched network such as the Internet. An encoder at the sending end derives p redundancy blocks from each group of a k payload blocks and concatenates the redundancy blocks, respectively, with payload blocks in the next group of k payload blocks. At the receiving end, a decoder may recover up to p missing packets in a group of k packets, provided with the p redundancy blocks carried by the next group of k packets. The invention thereby enables correction from the loss of multiple packets in a row, without significantly increasing the data rate or otherwise delaying transmission.

Abstract: A complete collision avoidance contention resolution protocol is provided for networks with stations communicating over a shared access communication medium. The protocol is used where a physical layer connected to the communication medium uses a carrier modulation scheme with multiple frequencies. Stations on the network that desire access to the communication medium use a carrier modulation scheme with multiple frequencies. Stations that desire access simultaneously transmit a single frequency selected at random from a set of physical layer frequencies during an open-contention-interval. At the same time, the stations listen to a combined frequency signal and analyzes it for frequency content. If one station whose own frequency matches the highest frequency signal in the combined signal, the station gains access to a communication medium. If more than one station have the same highest frequency signal in the combined signal, no station gains access to the medium.