3com Corporation

Hewlett-packard Development Company, L.p.

3com Technologies

Hewlett Packard Enterprise Development LP

Hewlett-packard Company

David J Law

Paul J Moran

Eugene O'Neill

Alan R Poulter

Quang T Tran

Edele O'Malley

Daniel M O'Keeffe

Justin A Drummond-Murray

Bryan J Donoghue

Kam Choi

Peter Furlong

Nigel Horspool

James Scott Hiscock

Tadhg Creedon

Kevin Loughran

Jerome Nolan

Christopher Alan Walker

Nicholas Mark Stapleton

Edward Turner

Robin Parry

Maurice A Goodfellow

Patrick Gibson

Patrick Michael Overs

Richard N Bayfield

Sharon L Wiles

Eoghan Stack

Peter J Wilson

Mark A Bobbitt

Paul Cramphorn

Gareth Edward Allwright

Christopher Hay

Terence D Lockyer

Neil J Clifford

Christopher Byham

Steven Brewer

David Wright

Rob Parry

Maunte A Goodfellow

Pauric O'Callaghan

Neil J MacDonald

Hana Hailichova

A method for managing a number of Ethernet links includes identifying a number of Ethernet links to utilize a number of channels of a cable based on a number of capabilities and a number of policies of a number of media access controllers (MACs) and a number of physical layer entities (PHYs), determining a number of Ethernet link types to be configured for the cable based on the capabilities and policies of the MACs and PHYs, negotiating a number of parameters to allow multi-channel ports of a number of nodes connected to the cable to establish communications through the Ethernet links based on the determined Ethernet link types and the utilized channels, and managing the cable configuration describing the MACs to be supported by the channels within the cable based on the policies.

Managing a number of ethernet links

In one implementation, a network scheduling method includes collecting information describing pending traffic for a network and generating a plurality of initial scheduling plans for network resources associated with the pending traffic within the network. The network scheduling method also includes analyzing a plurality of scheduling plans derived from the plurality of initial scheduling plans, and defining a current scheduling plan for the network resources from the plurality of scheduling plans.

Network scheduling

In one implementation, a traffic tuning system includes an aggregation engine, an option engine, and a comparison engine. The aggregation engine is to collect information about pending traffic for a network from applications communicating via the network. The option engine is to generate a plurality of potential scheduling plans from the information about the pending traffic based on a plurality of traffic tuning parameters and one or more network paths for the pending traffic. The comparison engine is to compare the plurality of potential scheduling plans and to define a tuned scheduling plan based on comparing the plurality of potential scheduling plans.

Network traffic tuning

In one embodiment, a method is described for detecting an operational failure between the network unit and an adjacent network unit in the stack; controlling the switching engine to redirect packets which would otherwise be sent from a particular port to the adjacent network unit to be forwarded from another port to be sent to a different network unit in the stack; and entering the switching engine into a bypass mode in response to control data indicating an operational failure between at least two other network units in the stack to cause packets to be forwarded without being re-directed by the switching engine.

Cascade system for network units

The occurrence of false positives and the post-processing of digital streams subjected to examination by a deterministic finite state machine for character strings are reduced by combining location-based pattern matching, e.g. on packet headers, and content-based pattern matching, e.g. on payloads of packets. One scheme allows automatic transition from a header match state into an initial state of a content matching machine. Another scheme is based on a rules graph defining strings of match states and the examination of a list of match states (rather than characters) which have been previously determined, for example by means of header matching and content matching. The latter is also capable of comparing offset and depth values associated with the match states with offset and depth criteria.

Signature checking using deterministic finite state machines

An apparatus including logic to receive a data packet comprising a string of characters, said apparatus having a plurality of states and at least one state for every character position in the string of characters; logic to examine the string of characters for matches with a plurality of predefined values, beginning with an initial character; and logic to execute forward exit transitions from any of the plurality of states based upon the examination of the characters, wherein a current state of the apparatus represents a count of a number of characters from the initial character of the string of characters.

Positionally dependent pattern checking in character strings using deterministic finite automata

A network stack includes a plurality of network units each of which includes a multiplicity of ports for receiving and forwarding addressed data packets, at least two cascade ports and a switching engine for forwarding received packets to at least one port in accordance with address data in the packets and a cascade connection including, for each of two opposite directions around the stack, at least one unidirectional path for data packets composed of links each between a respective cascade port on a network unit and a corresponding cascade port on the next network unit.

A deterministic finite state machine organised for the detection of positionally significant matches of characters in a string of characters examines each character in turn to determine a exit transition for a current state of the machine to another state The machine responds to an examination of the string of characters by executing in response to a first character at the commencement of the string a transition from an initial state to another state. The machine has at least one state for every character position, includes a exit transition from each state for each character to another state; and possesses only forward exit transitions each from any of the states whereby the current state of the machine unambiguously represents a count of the number of characters from the commencement of the string. The machine may include at least one match state which indicates that all character matches in the string required by at least one respective rule have been detected. Some but not all the states in the multiplicity of states each have a single exit transition for any value of a respective character in the string. At least some of the states in the multiplicity of states each define an exit transition to a state indicating 'no match'. The machine may be disposed to cease its examination of the character string on attaining a 'no match'state.

The deciphering of fragmented enciphered IP packets is performed without requiring reassembly of the fragments. fragmented packets. When a first frame is deciphered a characteristic poly-tuple is saved against the state of the cipher, particularly an output vector. When the next frame comes in, the cipher would continue on from that previously saved state after a look-up of the poly-tuple. Each frame would then be sent on, deciphered, but still representing a fragment of the original packet. The poly-tuple employed for the look-up includes the identity and protocol fields from the IP header and at least one of the source IP address and the destination IP address. The deciphering process may commence with the combination of input data with an initializing vector and proceed by combining input data with a vector fed back from the output of the deciphering engine. The saved cipher state is employed as the initializing vector for the next frame.

Deciphering of fragmented enciphered data packets

A deterministic finite state machine is operated to detect any one of a plurality of digital signatures each corresponding to a succession of characters and each defined by a sequence of states in the state machine. The machine is organized such that for each state after the first in any sequence there are not more than two allowed exit transitions of which one is to a default state. Input characters are examined to determine a transition from a current state of the machine to a next state. When the machine responds to an input character to perform a transition to the default state, the input character is re-examined to determine the next state of the state machine. The reduction in transitions saves considerable space in memory.

Pattern matching using deterministic finite automata and organization of such automata

Network units such as switches for use in a cascaded stack are organised to provide a cascade connection in the form of a dual unidirectional connection so that, in its ordinary configuration, there is at least one and preferably more than one unidirectional ring for each direction around the cascade, each ring including a respective port on each unit. For each ring, each port on a unit is connected by a respective link to a corresponding port on the preceding unit and the following unit. The units provide a self-healing operation in the event of various kinds of operational failure. The self-healing operation includes loop-back of packets in units adjacent the failure and bypass of a packet switching process for other units. The units include control logic for passing control frames containing status information relating to the units and links between them and for co-operation with a CPU to control a switching engine to perform the self-healing operation in accordance with that status information. The units forward on the cascade packets with headers that identify a destination port and the unit on which that port is located and also indicate which units have and have not been traversed by a packet.

A connecting unit for use in a system comprising a 'stack' of network communication units having a cascade connection has three ports having lines for forwarding and receiving data packets and for forwarding and receiving control messages. The connecting unit increments a first signal value defining an identification number received by way of a control message at a first port, provides the received signal value by way of a control message to the third port and provides the incremented signal value by way of a control message to the second port. The connecting unit also receives a second signal value defining an active unit count by way of a control message at the first port and provides the second signal value, incremented or not in dependence on a control message received at the third port, in a control message at the second port. The first signal values (UnitIDs) are used to establish the numbering of the units in the stack and the second signal values are used to compute a count of the 'active' units in the stack.

Cascade architecture and operation for packet-based communication systems

A control device for a unit in a cascade connection of network units includes control logic which increments a count of active units and passes the count to the next control device. The count is initiated and terminated by an absence of control messages at the down port and up port respectively. The incremented count is passed up the cascade and a final count is passed down the cascade.

Cascade control architecture and operation for packet-based communication systems

A network device is arranged to transmit a specific identification such as the device's MAC address in Next Pages of auto-negotiation and to determine a link status to be 'down' if 'Next Pages' containing that address are received by the same port. The invention avoids the use of signal detect pins for fiber optic links.

Network device including detection of link status employing auto-negotiation

Growing community of inventors

Kempston, United Kingdom

David J Law