Abstract: A system for dynamically implementing a plurality of virtual local area networks (“VLANs”) across multiple sites is provided. The system includes a first VLAN-capable switch at a first site; a first system under test (“SUT”) connected to the first VLAN-capable switch via a first burn rack switch; a second VLAN-capable switch located at a second site remote from the first site; a second SUT connected to the second VLAN-capable switch via a second burn rack switch. The first and second VLAN-capable switches are connected such that the first and second SUTs are connected to a single virtual private network (“VPN”). The connection may include either first and second routers respectively connected to the first and second VLAN-capable switches and interconnected via a T1 line or an ATM connection.
August 26, 2003
Date of Patent:
May 12, 2009
Dell Products L.P.
Dennis M. Wiedeman, Eugene Baker, Dwayne R. Potter, Richard Amberg
Abstract: Herein disclosed is a unicast-to-multicast converting apparatus comprising: a unicast network interface for receiving monitoring data including a plurality of UDP unicast data packets; a packet buffer for temporally storing the UDP unicast data packets received from the unicast network interface; a converting table storage section for storing conversion key information and a conversion rule table indicative of relationship between source entities and destination entities; a converting judging section for sequentially comparing each of the UDP unicast data packets stored in the packet buffer with the conversion key information stored in the converting table storage section to judge that a UDP unicast data packet is to be multicast when the UDP unicast data packet matches with the conversion key information and determining UDP unicast data packets to be multicast; a converting section for converting the UDP unicast data packets to be multicast determined by the converting judging section into a plurality of UDP
Abstract: A method of determining whether a wireless packet data service can be activated in a dormant state. To activate one of a plurality of packet data services in the dormant state, a BS transmits to an MS a Page Message containing an SR ID identifying the service to be activated. If a service instance for the service is unavailable, the MS transmits to the BS a response message indicating that the service cannot be reconnected. The BS then terminates immediately, thereby saving radio resources and improving system performance.
Abstract: A method of measuring jitter of a packet flow includes identifying the data packet flow at each of a first and second network locations by analyzing the data fields of each of the packets in the flow. The method associates a transmit time code with each packet transmitted from the first location, and associates a receive time code with each packet received at the second location. The method calculates inter-arrival times for consecutive pairs of packets by (i) subtracting the transmit time code of the first packet from the transmit time code of the second packet, (ii) subtracting the receive time code associated with the first packet from the receive time code associated with the second packet, and (iii) subtracting the results. The method includes calculating a jitter value as a smoothed version of two or more inter-arrival times, smoothed over a predetermined number of pairs of consecutive packets.
May 18, 2001
Date of Patent:
March 31, 2009
EXFO Service Assurance, Inc.
Kaynam Hedayat, Daniel S. Pyrik, Steven A. DesRochers
Abstract: A radio line is easily influenced in its nature by attenuation or reflection of an electromagnetic wave or the like and the surrounding environment. Due to this fact, a variation of the data transfer speed frequently occurs at the time of image streaming so as to become a hindrance to reproduction of an image at the receiving terminal. A distribution server is provided with a multiplexer for multiplexing information indicating the transmission start time for the image data and a switching unit for switching an image bit rate in response to a request from the receiving terminal. The receiving terminal uses information indicating a transmission start time for the image data, monitors the receiving bit rate and sends out a request for transmission of the most-suitable image bit rate in response to a comparison thereof.
Abstract: Methods and systems provide approaches to start code emulation prevention at a granularity higher than the bit level. By operating at a level other than the bit level, processing capability requirements on both the encoder and decoder side can be reduced. In accordance with one or more embodiments, a start code emulation prevention method looks for data patterns relative to fixed-size data portions larger than single bits. When a particular pattern is found, start code emulation prevention data is inserted to prevent start code emulation. The inserted data is larger than a single bit and, in some embodiments, comprises a byte. When a decoder decodes data that has had start code emulation prevention data inserted, it can easily identify legitimate start codes and then can remove the start code emulation prevention data to provide the original data that was protected.
Abstract: In a communication network system having a multi-switch Fiber Channel fabric, adjacent switches are communicatively coupled together by a plurality of links. The links are selectively determined to join a trunked group for enabling frames received at one switch to be routed over the links in the trunked group to the adjacent switch in an evenly distributed manner. In one embodiment, a link within the trunked group is coupled to a pair of ports residing on adjacent switches each having a designated trunking master port. The traffic load at one switch is routed through the trunking master port which distributes the load across multiple links and guarantees that the load is received at the adjacent switch with “in-order” delivery.
June 1, 2001
Date of Patent:
November 4, 2008
Brocade Communications Systems, Inc.
David C. Banks, Kreg A. Martin, Shunjia Yu, Jieming Zhu, Kevan K. Kwong
Abstract: A redundant network interface for ethernet devices is disclosed. The redundant network interface provides connections between one or more Ethernet devices and two or more independent networks. The redundant network interface device also tests an active primary Ethernet connection path, and when a failure or inactive path is detected, the redundant network interface device reroutes the messages to alternate communication path.
Abstract: Connecting a new node to a double ring network or establishing a new network having a double ring network is greatly simplified by automatic mapping of logical interfaces to physical interfaces to conform to a mapping or polarity observed by other nodes in the network. A node may discover the network polarity via a message received from an adjacent node and, if necessary, invert the mapping between its two logical interfaces and two physical interfaces. This facilitates installation by relaxing the requirement that the correct media pair be connected to the correct node physical interface. Nodes equipped with this automatic side selection capability may interoperate with nodes that are not so-equipped.
Abstract: A DOCSIS 2.0 compatible sniffer which can receive legacy DOCSIS 1.x TDMA bursts as well as DOCSIS 2.0 SCDMA bursts. One embodiment uses two cable modems in the sniffer, one to capture downstream data bursts and the other to capture downstream messages and to recover the downstream symbol clock and generate an upstream reference clock which is phase coherent with the recovered downstream symbol clock. The reference clock is used by a cable modem termination system to capture upstream SCDMA DOCSIS 2.0 bursts. DOCSIS 1.x TDMA bursts may also be captured. Other embodiments use a DOCSIS 2.0 compatible modem in the sniffer to lock onto a downstream, register as a cable modem in the system and capture downstream messages in order to derive the correct timing to generate control signals to control burst capture circuitry in the sniffer to capture DOCSIS 1.x and 2.0 upstream bursts.
Abstract: Systems and methods are provided for providing communication between an ATM layer device and multiple multi-channel PHY layer devices, which increase the number of multi-channel PHY layer ports supported by the ATM layer device.