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US 10,764,208 B2Granted
Distributed switch architecture
AssigneeAvago Technologies International Sales Pte. Limited
InventorsAmit Kumar, William Brad Matthews, Bruce Hui Kwan, Puneet Agarwal
Life of this patent
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Abstract
A distributed switch architecture supports very high bandwidth applications. For instance, the distributed switch architecture may be implemented for cloud networks. The architecture scales by organizing traffic management components into tiled structures with distributed buffering. The tile structures are replicated and interconnected to perform transfers from ingress to egress using an interconnect bandwidth scheduling algorithm. Bandwidth scaling may be achieved by adding more tiles to achieve higher bandwidth. The interconnect in the architecture may be swapped out depending on implementation parameters, e.g., physical efficiency.
Claims18
A method comprising:
- establishing a distributed buffering architecture comprising:
- an input packet buffer in an ingress tile;
- an output packet buffer in an egress tile, the input packet buffer and the output packet buffer not being located on shared memory;
- and
- at least one buffer in a switching fabric, the at least one buffer in the switching fabric being separate from the input packet buffer and the output packet buffer and being located between an ingress and an egress of the switching fabric;
- connecting the ingress tile and the egress tile with the switching fabric;
- executing a distributed bandwidth grant mechanism between the ingress tile and the egress tile, through the switching fabric, wherein the distributed bandwidth grant mechanism comprises a store-and-forward bandwidth credit grant mechanism;
- tracking, with an ingress queue scheduler, active and inactive virtual output queues (VoQs) defined in the input packet buffer;
- issuing a bandwidth credit request message to the egress tile for a selected active VoQ among the active VoQs, to report that the selected active VoQ should receive credits at a rate specified by a pre-configured QoS policy;
- issuing a bandwidth status update message to the egress tile for a selected inactive VoQ among the inactive VoQs, to report that the selected inactive VoQ should stop receiving credits because the selected inactive VoQ has a credit surplus and/or no more data to transmit;
- making a cut through decision on whether a packet cell is eligible to flow from the ingress tile to the egress tile without waiting for entire packet buffering;
- and
- operating, in response to a determination that the cut through decision is a grant, in a cut through mode in which the packet cell flows from the ingress tile to the egress tile without waiting for the entire packet buffering.
10 more elements
A machine comprising:
- an ingress tile comprising:
- an input packet buffer configured to store a whole received packet and an individual packet cell payload for an arriving packet;
- and
- a staging buffer configured to store a packet cell pointer to the packet cell payload while a cut through decision is made for the arriving packet corresponding to the individual packet cell payload;
- an egress tile comprising:
- an output packet buffer configured to define a port-specific cut through buffer;
- and
- circuitry configured to make the cut through decision, the cut through decision being a decision on whether the packet cell payload is eligible to flow from the ingress tile to the egress tile without waiting for entire packet buffering;
- a switching fabric, including at least one buffer that is separate from the input packet buffer and the output packet buffer, the at least one buffer being located between an ingress and an egress of the switching fabric, the switching fabric being configured to connect the ingress tile to the egress tile;
- and
- bandwidth allocation circuitry distributed between the ingress tile and the egress tile, the bandwidth allocation circuitry being configured to
- execute a distributed bandwidth grant mechanism between the ingress tile and the egress tile, through the switching fabric, wherein the distributed bandwidth grant mechanism comprises a store-and-forward bandwidth credit grant mechanism;
- perform tracking, with an ingress queue scheduler, active and inactive virtual output queues (VoQs) defined in the input packet buffer;
- issue a bandwidth credit request message to the egress tile for a selected active VoQ among the active VoQs, to report that the selected active VoQ should receive credits at a rate specified by a pre-configured QoS policy;
- and
- issue a bandwidth status update message to the egress tile for a selected inactive VoQ among the inactive VoQs, to report that the selected inactive VoQ should stop receiving credits because the selected inactive VoQ has a credit surplus and/or no more data to transmit,
- wherein the switching fabric is configured, in response to a determination that the cut through decision is a grant, to operate in a cut through mode in which the individual packet cell payload flows from the ingress tile to the egress tile without waiting for the entire packet buffering.
14 more elements
A machine comprising:
- an ingress tile comprising:
- an input packet buffer configured to store a whole received packet and an individual packet cell payload for an arriving packet;
- and
- a staging buffer configured to store a packet cell pointer to the packet cell payload while a cut through decision is made for the arriving packet corresponding to the individual packet cell payload;
- an egress tile comprising:
- an output packet buffer configured to define a port-specific cut through buffer;
- and
- circuitry configured to make the cut through decision, the cut through decision being a decision on whether the packet cell payload is eligible to flow from the ingress tile to the egress tile without waiting for entire packet buffering;
- a switching fabric connecting the ingress tile to the egress tile,
- wherein the machine further comprises circuitry configured to
- execute a distributed bandwidth grant mechanism between the ingress tile and the egress tile, through the switching fabric, wherein the distributed bandwidth grant mechanism comprises a store-and-forward bandwidth credit grant mechanism;
- perform tracking, with an ingress queue scheduler, active and inactive virtual output queues (VoQs) defined in the input packet buffer;
- issue a bandwidth credit request message to the egress tile for a selected active VoQ among the active VoQs, to report that the selected active VoQ should receive credits at a rate specified by a pre-configured QoS policy;
- and
- issue a bandwidth status update message to the egress tile for a selected inactive VoQ among the inactive VoQs, to report that the selected inactive VoQ should stop receiving credits because the selected inactive VoQ has a credit surplus and/or no more data to transmit, and
- wherein the switching fabric is configured, in response to a determination that the cut through decision is a grant, to operate in a cut through mode in which the individual packet cell payload flows from the ingress tile to the egress tile without waiting for the entire packet buffering.
13 more elements
Dependencies are inferred from the claim text.