We present Dionysus, a system for fast, consistent network updates in software-defined networks. Dionysus encodes as a graph the consistency-related dependencies among updates at individual switches, and it then dynamically schedules these updates based on runtime differences in the update speeds of different switches. This dynamic scheduling is the key to its speed; prior update methods are slow because they pre-determine a schedule, which does not adapt to runtime conditions. Testbed experiments and data-driven simulations show that Dionysus improves the median update speed by 53--88% in both wide area and data center networks compared to prior methods.

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Dynamic scheduling of network updates

One embodiment of the present invention provides a switch. The switch includes a port that couples to a server hosting a number of virtual machines. The switch also includes a set of virtual port grouping information and a virtual port grouping mechanism. During operation, the virtual port grouping mechanism determines whether a frame is traveling from a virtual port group to the same virtual port group. If the frame is not traveling to the same virtual port group, the virtual port grouping mechanism prevents the frame from being forwarded.

Virtual port grouping for virtual cluster switching

A data transmission system includes probes (probe A, probe B) connected between end user sites (site A, site B) and a data switching network (12). Each probe is connected to the switching network (12) via an access channel (20, 21, 26 or 27) wherein transmission circuits establish paths between the sites through the access channel (20, 21, 26 or 27) and switching network (12). The probes capture and retransmit data traveling between the sites over respective transmission circuits, and can thereby insert service level anaylsis (SLA) messages into data traffic in order to actively communicate network performance information to other probes. For each transmission circuit, the probes periodically collect measurements related to one or more network performance metrics, including round-trip delay (RTD), data delivery ratio (DDR) and network availability. During each SLA measurement cycle, a sequence of SLA messages is exchanged over each transmission circuit, which messages contain data used to determine RTD and DDR.

Method and apparatus for performing service level analysis of communications network performance metrics

An ATM network switch and method of utilization for adaptively providing integrated services therein is disclosed. In providing such integrated services, if the allocated bandwidth for one connection has been consumed, or if the connection is not entitled to allocated bandwidth, the connection can optionally use dynamic bandwidth arbitration, or a combination of both allocated and dynamic. The switch includes an input port processor, a bandwidth arbiter, and an output port processor. Cells are transmitted from the input to the output, under the control of respective port processors and the bandwidth arbiter. Flow control is implemented on a per-connection basis. Individual queues are then assigned to traffic type groups in order to provide traffic type flow control. Based upon prioritization information associated with the cell at the input, cells are prioritized and transmitted from the output, with each cell maintained in the same order, relative to other cells on a connection, in which it was received.

Allocated and dynamic bandwidth management

One embodiment of the present invention provides a switch. The switch includes a first port configured to receive Transparent Interconnection of Lots of Links (TRILL) traffic; a second port configured to receive Fiber Channel (FC) traffic; and a third port configured to transmit received TRILL or FC traffic based on a Fiber Channel over IP (FCIP) protocol.

Converged network extension

An arbitrary node that belongs to a virtual LAN sends a request packet including a count value indicating the number of communication hops across nodes to each of its adjacent nodes that belong to the virtual LAN and are adjacent. Upon receiving the request packet, each of the adjacent nodes sends the request packet in which the count value is incremented or decremented, as predetermined, to each of its adjacent nodes that belong to the virtual LAN and are adjacent to the node, excluding a sender of the request packet received, and sends a reply packet including the sender's address (sender address), an address of the node that is a replying node (replying node address), and the count value to a given return destination. The return destination collects reply packets sent thereto and keeps track of the topology of the nodes constituting the virtual LAN from information contained in the reply packets.

Method and apparatus for keeping track of virtual LAN topology in network of nodes

A system for monitoring an ATM cross-connecting apparatus by inputting a test cell through a path for a main signal into the ATM cross-connecting apparatus, and examining the cell after the cell passed through the ATM cross-connecting apparatus. An initial value of a PN sequence and the PN sequence generated based on the initial bit sequence is written in the test cell before inputting to the ATM cross-connecting apparatus. When examining the test cell, the initial bit sequence and the PN sequence are read from the cell, a PN sequence is generated based on the initial bit sequence, and is then compared with the PN sequence read from the test cell to detect an error in the test cell. In addition, a bit pattern indicating a primitive polynomial to generate the PN sequence may be written in the test cell. In this case, the bit pattern is used for generating the PN sequence when examining the test cell. Further, the same VPI values may be written in both the header and the information field of the test cell before inputting the cell to the ATM cross-connecting apparatus, and the VPI value in the information field is compared with a VPI value in the header of the test cell when examining the test cell.

System for monitoring ATM cross-connecting apparatus by inside-apparatus monitoring cell

A cross-connection apparatus for B-ISDN includes plural interface units, multiplexers, virtual path identifier (VPI) conversion tables, demultiplexers, and loop-back units and a switch unit The interface unit has a reception port for receiving an ATM cell or inserting a monitor cell, and a transmission port for transferring the ATM cell or extracting the monitor cell; The multiplexer is operatively connected to corresponding interface unit for multiplexing the monitor cell; The VPI conversion tables is operatively connected to corresponding multiplexer for converting the VPI to change a transmission route of the monitor cell; The switch unit is operatively connected to the VPI conversion tables for switching the transmission route of the monitor cell based on the VPI; The demultiplexer is operatively connected to the switch unit for demultiplexing the monitor cell and transferring the monitor cell to the transmission port; The loop-back unit is operatively connected to corresponding interface unit for changing the transmission route so as to transfer the monitor cell to the same interface unit which the monitor cell is inserted, and as a result, the apparatus can be monitored by comparing the inserted monitor cell with the extracted monitor cell in the same interface unit

Cross-connection apparatus for b-isdn

We have developed a fiber-longitudinal monitor that visualizes distance-wise optical power throughout the entire multi-span link by using the signal waveform obtained by a coherent receiver placed at the receiver-end. This is an in-situ monitor that estimates power profile along the link-longitudinal axis from its incoming signal by employing digital post-processing of coherent receiver data. We demonstrate through experiments that our method can simultaneously visualize and localize multiple power attenuation anomalies over fiber transmission links. This data processing-based monitoring by digital coherent receiver will be a key element in future autonomous optical networks driven by rich information on physical-layer.

Kazuyuki Tajima

Papers

Method and apparatus for keeping track of virtual LAN topology in network of nodes

System for monitoring ATM cross-connecting apparatus by inside-apparatus monitoring cell

Cross-connection apparatus for b-isdn

Fiber-Longitudinal Anomaly Position Identification Over Multi-Span Transmission Link Out of Receiver-end Signals

Experimental Demonstration of a Coherent Receiver that Visualizes Longitudinal Signal Power Profile over Multiple Spans out of Its Incoming Signal