Cisco Technology, Inc.

Georges Akis

Peter Clarke Newman

Krishnan Subramani

Vinod Mitulal

Mohammadreza Alizadeh Attar

Francis Matus

Kinjal Shah

Thomas James Edsall

Rong Pan

Luca Cafiero

Kit Chiu Chu

Shang-Tse Chuang

Francisco M Matus

Sarang M Dharmapurikar

Sha Ma

Mario Mazzola

Sharad Vasantrao Chole

Ganlin Wu

Felice Bonardi

The subject technology relates to the management of a shared buffer memory in a network switch. Systems, methods, and machine readable media are provided for receiving a data packet at a first network queue from among a plurality of network queues, determining if a fill level of a queue in a shared buffer of the network switch exceeds a dynamic queue threshold, and in an event that the fill level of the shared buffer exceeds the dynamic queue threshold, determining if a fill level of the first network queue is less than a static queue minimum threshold.

Queue protection using a shared global memory reserve

Systems, methods, and computer-readable storage media for monitoring queue occupancy in a network buffer, detecting microbursts, and analyzing the same. An ASIC device can monitor a queue occupancy value of a network buffer, detect when the queue occupancy value exceeds a first predetermined threshold queue occupancy, create a record with a time that the queue occupancy value exceeds the first predetermined threshold queue occupancy, a queue occupancy value at the time that the queue occupancy value exceeds the first predetermined threshold queue occupancy, detect when the queue occupancy value falls below a second predetermined threshold queue occupancy, and determine a maximum queue occupancy value between the time that the queue occupancy value exceeded the first predetermined threshold queue occupancy and a time that the queue occupancy value falls below the second predetermined threshold queue occupancy, and add to the record the maximum queue occupancy value, a time of the maximum queue occupancy value, the time that the queue that the queue occupancy value falls below the second predetermined threshold queue occupancy and the queue occupancy value at the time that the queue occupancy value falls below the second predetermined threshold queue occupancy.

Detecting and measuring microbursts in a networking device

A network device receives a packet at a port from among a number of ports. A queue threshold is randomly adjusted for a queue having an output buffer to which the packet is stored. When a fullness of the queue exceeds the adjusted queue threshold, at a time when the packet is to be enqueued into the queue, an action is performed. The action includes either dropping the received packet, or flow-controlling the port at which the packet is received.

Providing source fairness on congested queues using random noise

A network switch includes a buffer to store network packets linked to queues to feed the packets to output ports of the switch associated with the queues. The buffer is shared dynamically among multiple traffic pools. The network switch determines per-pool dynamic thresholds each based on an amount of unused buffer space, and per-queue dynamic thresholds based on amounts of unused buffer space available in the pools with which the queues are associated. The network switch receives packets, and for each received packet, the network switch admits the packet to the pool with which the packet is associated and the queue for which the packet is destined if (i) occupancy of the associated pool is less than the corresponding per-pool dynamic threshold, and (ii) occupancy of the queue for which the packet is destined is less than the corresponding per-queue dynamic threshold, and otherwise drops the packet.

Dynamic protection of shared memory used by output queues in a network device

Provided are a method, a non-transitory computer-readable storage device and an apparatus for managing use of a shared memory buffer that is partitioned into multiple banks and that stores incoming data received at multiple inputs in accordance with a multi-slice architecture. A particular bank is allocated to a corresponding slice. Received respective data packets are associated with corresponding slices based on which respective inputs they are received. Determine, based on a state of the shared memory buffer, to transfer contents of all occupied cells of the particular bank. Writes to the bank are stopped, contents of occupied cells are transferred to cells of one or more other banks associated with the particular bank's slice, information is stored indicating where the contents have been transferred, and the particular bank is returned to a shared pool after transferring is completed.

Dynamic packet buffers with consolidation of low utilized memory banks

A network switch includes a buffer to store network packets and packet descriptors (PDs) used to link the packets into queues for output ports. The buffer and PDs are shared among the multiple traffic pools. The switch receives a multicast packet for queues in a given pool. The switch determines if there is unused buffer space available for packets in the given pool based on a pool dynamic threshold, if there is unused buffer space available for packets in each queue based on a queue dynamic threshold for the queue, if there are unused PDs available to the given pool based on a pool dynamic threshold for PDs, and if there are unused PDs available for each queue based on a queue dynamic threshold for PDs for the queue. The network switch admits the packet only into the queues for which all of the determining operations pass.

Dynamic protection of shared memory and packet descriptors used by output queues in a network device

A ternary content-addressable memory (TCAM) that is implemented based on other types of memory (e.g., SRAM) in conjunction with processing, including hashing functions. Such a H-TCAM may be used, for example, in implementation of routing equipment. A method of storing routing information on a network device, the routing information comprising a plurality of entries, each entry has a key value and a mask value, commences by identifying a plurality of groups, each group comprising a subset number of entries having a different common mask. The groups are identified by determining a subset number of entries that have a common mask value, meaning at least a portion of the mask value that is the same for all entries of the subset number of entries.

Ternary content addressable memory utilizing common masks and hash lookups

An example method, system, and switching element are provided and may provide for an egress port to be configured to receive a plurality of data packets, each of the plurality of data packets being a class of a plurality of classes. A buffer may communicate with the at least one data port interface. A memory management unit may be configured to enable and disable transmission of the plurality of classes of the plurality of data packets based on a metering policy; and place the plurality of data packets in the buffer.

Supporting quality of service differentiation using a single shared buffer

A multi-stage network switch comprises a plurality of ingress port subsystems each comprising one or more ingress ports configured to receive packets. The switch also comprises a plurality of unscheduled crossbar switching elements connected to the ingress port subsystems that are configured to receive one or more packets from at least one of the ingress port subsystems. The switch further comprises a plurality of egress port subsystems each comprising a memory and a plurality of egress ports. The memory comprises at least one shared egress buffer configured to receive any packets forwarded by the crossbar switching elements from the ingress port subsystems directed to the egress port subsystem, and the egress ports are configured to transmit the packets received in the shared egress buffer.

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Los Altos, CA, United States of America

Georges Akis