Advanced Micro Devices Corporation

Globalfoundries Inc.

Shr-Jie Tzeng

Peter Ka-Fai Chow

Yatin Acharya

Bahadir Erimli

Somnath Viswanath

Gopal S Krishna

Mrudula Kanuri

Chandan Egbert

Xiaohua Zhuang

A network switch includes network switch ports, each including a port filter configured for detecting user-selected attributes from a received layer 2 type data frame. Each port filter, upon detecting a user-selected attribute in a received layer 2 type data frame, sends a signal to a switching module indicating the determined presence of the user-selected attribute, enabling the switching module to generate a switching decision based on the corresponding user-selected attribute and based on a corresponding user-defined switching policy. The switching policy may specify a priority class, or a guaranteed quality of service (e.g., a guaranteed bandwidth), ensuring that the received layer 2 type data frame receives the appropriate switching support. The user-selected attributes for the port filter and the user-defined switching policy for the switching module are programmed by a host processor. Hence, the integrated network switch is able to perform advanced switching operations for layer 2 type data packets to ensure quality of service requirements, independent of priority information specified in the layer 2 type data packets, based on the user-selected attributes in the layer 2 type data packets and the user-defined switching policies established for the switching module.

Arrangement in a network switch for prioritizing data frames based on user-defined frame attributes

A multiport switch includes an action generator that creates action tags describing how data frames received by the switch are to be forwarded. A port filter generates policy equations and a differential services code point (DSCP) signal for the received packets. A decoder and an action memory in the action generator choose the highest priority policy equation and use the policy equation to look up priority information for the data frame. A state machine in the action generator receives the DSCP signal. A result tag interface receives a DSCP field from the state machine and the priority information from the action memory. Based on these signals, the result tag interface constructs the final action tag.

Action tag generation within a network based on priority or differential services information

A multiport switching device includes an Internal Rules Checker (IRC) that determines forwarding addresses for packets received at the device. The determined forwarding addresses may include a new MAC destination address that is to substituted for the MAC destination address of the received packet. In one implementation, the new MAC destination address is transmitted from the IRC to the dequeuing logic by transmitting pairs of adjacent words through the switch output queues. In other implementations, the new MAC destination address is transmitted from the IRC to the dequeuing logic by transmitting an index field to the output queuing logic or by having the IRC write the new MAC destination address directly to memory.

Address modification within a switching device in a packet-switched network

A network device includes a port filter, a first logic device, and a second logic device. The port filter receives a data frame and generates first data relating to the data frame. The first logic device generates second data for the received data frame. The second logic device receives the first data and the second data, determines whether the first data contains a valid first priority value, and assigns the valid first priority value to the data frame when the first data contains the valid first priority value. When the first data does not contain a valid first priority value, the second logic device determines whether the second data contains a valid second priority value, and assigns the valid second priority value to the data frame when the second data contains the valid second priority value.

System and method for deciding outgoing priority for data frames

A network device includes a receive module, a port filter, an action generator, processing logic, and a transmit module. The receive module receives a packet and detects whether the packet includes a router media access control (MAC) destination address. The port filter stores Internet Protocol (IP) source and destination addresses, determines whether an IP destination address associated with the packet has been stored, and identifies policy handling information for the packet. The action generator generates, based on the policy handling information, forwarding information for the packet. The forwarding information includes at least a port vector, and, when the IP destination address associated with the packet has been stored, a replacement MAC destination address. The processing logic determines a replacement MAC destination address when the IP destination address associated with the packet has not been stored. The transmit module transmits the packet based on the replacement MAC destination address.

System and method for performing layer 3 switching in a network device

A network device that controls the communication of data frames between stations performs an admission control procedure to reduce congestion on the network device. The network device receives data frames from a number of receive ports and reads a portion of a received data frame to determine a priority associated with the received data frame. When admission control is enabled, the network device determines whether to drop the received data frame based on the priority or some other predetermined criteria.

Admission control in a network device

A network switch, configured for performing layer 2 and layer 3 switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis, immediately upon receipt at the network switch port. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The templates may be programmed by a user and stored in an internal min term memory. Moreover, the multiple simultaneous comparisons enable the network switch to perform layer 3 switching for 100 Mbps and gigabit networks without blocking in the network switch.

Apparatus and method for identifying data packet at wire rate on a network switch port

A network device determines priority of a packet based on the priority of one or more previously-received packets. The network device includes a memory, a forwarding engine, and a processor. The memory stores priority information for one or more previously-received packets. The forwarding engine generates the priority information stored in the memory. The processor determines whether to apply the priority information stored in the memory to a received packet. When the priority information applies to the received packet, the processor sends the priority information to the forwarding engine. In response to the priority information, the forwarding engine bypasses the generation of priority information for the received packet and thus cuts down on processing time in the switch and, by doing so, reduces the end-to-end latency for the packet in the network.

Systems and methods for determining priority based on previous priority determinations

A host channel adapter configured for outputting packets according to InfiniBand&#x2122; protocol is implemented using partitioned link modules configured for performing selected link operations prior to outputting the packets. A pre-link module is configured for ordering work queue entries in an order based on determined service level and virtual lane priorities. The pre-link module outputs the ordered work queue entries to a transport service module configured for generating a transport layer header for the packets based on the respective work queue entries. Once the transport layer headers have been generated, a post-link module is configured for retrieval of the transport layer header and transport data and preparing the transmit data packets for transmission on the network by constructing the link layer fields. The post-link module outputs the transmit data packets based on the ordering and the flow control protocol for the appropriate virtual lanes.

Host channel adapter having partitioned link layer services for an infiniband server system

A host channel adapter configured for outputting packets according to InfiniBand&#x2122; protocol includes a queue pair attributes table having queue pair entries configured for specifying attributes of the respective queue pairs. Each queue pair entry includes a timestamp field for storing a time value. Upon teardown of a queue pair, a management agent stores a timestamp value, according to a prescribed time resolution interval, within the timestamp field and sets a corresponding wait state bit. The queue pair attributes table is accessed each prescribed time resolution interval for identification of idle queue pairs having passed a minimum idle interval at least equal to the prescribed time resolution interval. If an identified idle queue pair has a corresponding timestamp value indicating passing of the minimum time idle interval, the corresponding wait state bit is reset enabling the queue pair to be reused.

Queue pair wait state management in a host channel adapter

A network switch, configured for performing layer and layer switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The packet classifier includes a separate FIFO for storing the payload of the layer data frame (e.g., the IP packet), and buffer read logic that enables the packet classifier to read selected portions of the payload as it is received by the network switch port. The multiple simultaneous comparisons enable the network switch to perform layer switching for 100 Mbps and gigabit networks without blocking in the network switch.

Arrangement for reading a prescribed location of a FIFO buffer in a network switch port

A network switch, configured for performing layer and layer switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. The network switch uses the filter to detect the presence of an RFC 2205 compliant bandwidth reservation message from a host computer for reception by a router. The network switch is configured for selectively changing a requested quality of service specified in the bandwidth reservation message, based on a determined absence of available resources within the network switch. The network switch selectively increases the requested quality service, based on the determined absence of the available resources, to a value that will be denied by the router. Hence, the network switch can ensure that a router does not grant a bandwidth reservation message from a host computer that would cause the capacity of the network switch to be exceeded, without any modification to the host computer or the router, or any interference with the resource reservation protocol specified in RFC 2205.

Apparatus and method in a network switch for modifying a bandwidth request between a requestor and a router

A network switch, configured for performing layer and layer switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The templates may be programmed by a user and stored in an internal min term memory. Moreover, the multiple simultaneous comparisons enable the network switch to perform layer switching for 100 Mbps and gigabit networks without blocking in the network switch. The number of templates is minimized by comparing received bytes relative to the beginning of the layer frame, determined by a frame identifier which determines the layer header format that affects the beginning of the layer frame.

Frame identifier for identifying layer 2 data packet types for upper layer packet classification in a network switch port

A network switch, configured for performing layer and layer switching in an Ethernet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data attributes. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The templates may be programmed by a user and stored in an internal min term memory. Hence, the filter can identify selected attributes, such as whether the layer packet includes an SNMP packet or an HTTP packet, regardless of whether the IP frame is in IPv4 format or IPv6 format.

Arrangement for identifying data packet types from multiple protocol formats on a network switch port

A network switch, configured for performing layer 2 and layer 3 switching in an Ethemnet (IEEE 802.3) network without blocking of incoming data packets, includes a network switch port having a filter (i.e., a packet classifier module) configured for evaluating an incoming data packet on an instantaneous basis. The filter performs simultaneous comparisons between the incoming data stream of the data packet and multiple templates configured for identifying respective data protocols, enabling the network switch to perform layer 3 switching for 100 Mbps and gigabit networks without blocking in the network switch. Each template is composed of a plurality of min terms, wherein each min term specifies a prescribed comparison operation within a selected data byte of the incoming data packet. The templates may be programmed by a user and stored in an intemnal min term memory. A min term controller controls the storage of the min terms in the min term memory by determining for each min term a corresponding relevance of the corresponding selected data byte in evaluation of the incoming data packet. The min term controller stores each of the min terms in selected memory blocks of the min term memory based on the corresponding relevance to evaluation of the incoming data packet, enabling storage of the min terms to be optimized for simultaneous comparisons of the most relevant data bytes of the incoming data packet as they are received.

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Fremont, CA, United States of America

Shr-Jie Tzeng