- play_arrow Weighted Random Early Detection (WRED) and Explicit Congestion Notification (ECN)
- play_arrow WRED and Drop Profiles
- play_arrow Explicit Congestion Notification (ECN)
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- play_arrow CoS Queue Schedulers, Traffic Control Profiles, and Hierarchical Port Scheduling (ETS)
- play_arrow Queue Schedulers and Scheduling Priority
- Understanding Default CoS Scheduling and Classification
- Understanding CoS Scheduling Behavior and Configuration Considerations
- Understanding CoS Output Queue Schedulers
- Defining CoS Queue Schedulers
- Example: Configuring Queue Schedulers
- Defining CoS Queue Scheduling Priority
- Example: Configuring Queue Scheduling Priority
- Monitoring CoS Scheduler Maps
- play_arrow Port Scheduling and Shaping
- play_arrow Troubleshooting Egress Bandwidth Issues
- play_arrow Traffic Control Profiles and Priority Group Scheduling
- Understanding CoS Traffic Control Profiles
- Understanding CoS Priority Group Scheduling
- Understanding CoS Virtual Output Queues (VOQs)
- Defining CoS Traffic Control Profiles (Priority Group Scheduling)
- Example: Configuring Traffic Control Profiles (Priority Group Scheduling)
- Understanding CoS Priority Group and Queue Guaranteed Minimum Bandwidth
- Example: Configuring Minimum Guaranteed Output Bandwidth
- Understanding CoS Priority Group Shaping and Queue Shaping (Maximum Bandwidth)
- Example: Configuring Maximum Output Bandwidth
- play_arrow Hierarchical Port Scheduling (ETS)
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- play_arrow Data Center Bridging and Lossless FCoE
- play_arrow Data Center Bridging
- Understanding DCB Features and Requirements
- Understanding DCBX
- Configuring the DCBX Mode
- Configuring DCBX Autonegotiation
- Understanding DCBX Application Protocol TLV Exchange
- Defining an Application for DCBX Application Protocol TLV Exchange
- Configuring an Application Map for DCBX Application Protocol TLV Exchange
- Applying an Application Map to an Interface for DCBX Application Protocol TLV Exchange
- Example: Configuring DCBX Application Protocol TLV Exchange
- play_arrow Lossless FCoE
- Example: Configuring CoS PFC for FCoE Traffic
- Example: Configuring CoS for FCoE Transit Switch Traffic Across an MC-LAG
- Example: Configuring CoS Using ELS for FCoE Transit Switch Traffic Across an MC-LAG
- Example: Configuring Lossless FCoE Traffic When the Converged Ethernet Network Does Not Use IEEE 802.1p Priority 3 for FCoE Traffic (FCoE Transit Switch)
- Example: Configuring Two or More Lossless FCoE Priorities on the Same FCoE Transit Switch Interface
- Example: Configuring Two or More Lossless FCoE IEEE 802.1p Priorities on Different FCoE Transit Switch Interfaces
- Example: Configuring Lossless IEEE 802.1p Priorities on Ethernet Interfaces for Multiple Applications (FCoE and iSCSI)
- Troubleshooting Dropped FCoE Traffic
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- play_arrow CoS Buffers and the Shared Buffer Pool
- play_arrow CoS Buffers Overview
- play_arrow Shared Buffer Pool Examples
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Best-Effort Unicast Traffic
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Best-Effort Traffic on Links with Ethernet PAUSE Enabled
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Multicast Traffic
- Example: Recommended Configuration of the Shared Buffer Pool for Networks with Mostly Lossless Traffic
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- play_arrow CoS on EVPN VXLANs
- play_arrow Configuration Statements and Operational Commands
Configuring CoS Asymmetric Ethernet PAUSE Flow Control
Ethernet PAUSE flow control is a congestion relief feature that works by providing link-level flow control for all traffic on a full-duplex Ethernet link, including Ethernet links that belong to link aggregated (LAG) interfaces. Ethernet PAUSE works in both directions on the link. In one direction, an interface generates and sends PAUSE messages to stop the connected peer from sending more traffic. In the other direction, the interface responds to PAUSE messages it receives from the connected peer to stop sending traffic.
Asymmetric flow control allows you to configure the PAUSE functionality in each direction independently on an interface. The configuration for generating PAUSE messages and for responding to PAUSE messages does not have to be the same. It can be enabled in both directions, disabled in both directions, or enabled in one direction and disabled in the other direction.
Symmetric flow control means that the interface has the same configuration in both directions. The PAUSE generation and PAUSE response functions are both configured as enabled or they are both disabled. If you do not want to PAUSE all of the traffic on a link, you can use priority-based flow control (PFC) to selectively pause traffic based on its IEEE 802.1p code point.
Asymmetric flow control provides the ability to configure the receive buffer and transmit buffer Ethernet PAUSE actions independently on an interface. The buffers perform the following actions:
The receive buffers generate and send PAUSE messages to the connected peer to ask the peer to stop sending traffic for a time period specified in the PAUSE frame. The peer interface’s buffers may store outgoing frames until the PAUSE period elapses and the interface can resume sending traffic.
The transmit buffers respond to PAUSE messages received from the connected peer to stop sending traffic to the peer. The transmit buffer may store outgoing frames until the PAUSE period elapses and the interface can resume sending traffic.
Asymmetric flow control enables you to specify independently whether or not the interface receive buffer generates and sends PAUSE messages to stop the connected peer from transmitting traffic, and whether or not the interface transmit buffer responds to PAUSE messages it receives from the connected peer and stops transmitting traffic. The receive buffer configuration determines if the interface transmits PAUSE messages, and the transmit buffer configuration determines if the interface receives and responds to PAUSE messages:
Receive buffers on—Enable PAUSE transmission (generate and send PAUSE frames)
Transmit buffers on—Enable PAUSE reception (respond to received PAUSE frames)
You must explicitly set both the receive buffer and the transmit buffer to configure asymmetric flow control.
To configure asymmetric flow control on an interface:
content_copy zoom_out_map[edit interfaces interface-name ether-options] user@switch# set configured-flow-control rx-buffers (on | off) tx-buffers (on | off)
For example, to configure interface
xe-0/0/24to generate and send PAUSE messages but not to respond to received PAUSE messages:content_copy zoom_out_mapset interfaces xe-0/0/24 ether-options configured-flow-control rx-buffers on tx-buffers off
For example, to configure interface
xe-0/0/30to respond to received PAUSE messages but not to generate and send PAUSE messages:content_copy zoom_out_mapset interfaces xe-0/0/30 ether-options configured-flow-control rx-buffers off tx-buffers on
If you configure both buffers to be on, that
is equivalent to symmetric flow control. If you configure both buffers
to be off, there is no flow control (flow control is disabled).
