SDN QoS. Yatish Kumar - CTO Corsa

Transcription

1 SDN QoS Yatish Kumar - CTO Corsa

2 QoS is a design problem Who gets how much? For how long? Why?

3 QoS Tools Buffers Schedulers s Policers Meters Flow Control / BackPressure

4 Quick Summary of Each Tool Meters Mark packets that are in rate or out of rate Policers Drop Packets that are deemed out of rate Buffers Hold Packets in ONE or more queues Schedulers Pull Packets from queues s Pace how fast packets are transmitted Flow Control Signal the sources about congestion

5 Different Desires Network Owner : I would like to see all users get a fair share of the network, with no wastage Network Engineer : I need to make sure my critical in-band OAM is always given priority High Energy Physicist : We need to have some predictable guarantees, so we can schedule jobs. And we will scavenge all the left over bandwidth you have. Big Telescope Operator : Once the supernova goes off, we are streaming bits. Do not drop the data, or you ve got some explaining to do. Best Effort, Weighted Fair Queuing High Priority, Guaranteed Minimum Guaranteed Minimum, Weighted Fair Queueing Random Early Discard Bandwidth reservation with Shaping

6 Configure QoS tools to create different Classes Of Service Class 1 Best Effort, Weighted Fair Queuing Class 2 High Priority, Guaranteed Minimum Class 3 Guaranteed Minimum, Weighted Fair Queueing Random Early Discard Class 4 Bandwidth reservation with Shaping

7 SDN s Role In QoS Class 1 : Green : Port 22 Assign 1. a Port, ( Physical Egress) 2. a meter band ( Drop Precedence ) 3. a Class of Service ( Output Queue ) Packet Classification 4. edits packet to annotate ( Drop Precedence, Class of Service, Flow Control ) Eth-VLAN Priority IP-DSCP ( ECN ) MPLS-EXP

8 QoS and H/W Virtualization Application QoS Circuit Based QoS QinQ GRE VLAN VLAN MPLS Port Based Queues

9 QoS and Underlay Virtualization QinQ GRE VLAN 8 Classes of Service Which Logical Goes Next? Sorted List of Packets Ready to Go Optional Shaping on all L2 Circuits Port 2 P5: Egress Scheduler Port 2 P5: Egress Queue Which Logical Switch Port goes next? Port Based Queues

10 Take a deep breath And we will see how deep this rabbit hole goes

11 QoS and Overlay Virtualization 1 The network operator builds up Classes of Service that represent the needs of all users. High Priority, Guaranteed Minimum Best Effort, Weighted Fair Queuing Bandwidth reservation with Shaping Network Owner : I would like to see all users get a fair share of the network, with no wastage Network Engineer : I need to make sure my critical in-band OAM is always given priority High Energy Physicist : We need to Port 2 Port 5: Egress Scheduler Port 2 Port 5: Egress Queue have some predictable guarantees, so we can schedule jobs. And we will scavenge all the left over bandwidth you have. Big Telescope Operator : Once the supernova goes off, we are streaming bits. Do not drop the data, or you ve got some explaining to do.

12 QoS and Overlay Virtualization 1 The network operator builds up Classes of Service that represent the needs of all users. 2 Builds a Logical Network for different services. Exposes to Overlay network LHCONE BOD JRA Port 2 Port 5: Egress Scheduler Port 8: Egress Scheduler Port 2 Port 5: Egress Queue Port 8: Egress Queue

13 The Finger of Blame Very simple OVERLAY scenario - Multiple controller s only delivering core Logic - Only need to select a. Operator decides on all the details - Isolation from each other. Resources. And optionally BW isolation. - Full OpenFlow Multi-Table Virtualization. Not single table FlowVisor slicing. Quagga LHCONE BOD ONOS I ve got this really easy idea It s never going to work Why? You just need to map from VLAN to Port!! #@$# Difficult!! Very Clean Operator scenarios - complete control over physical resource and bandwidth allocation - correct balance of user driven forwarding and protection of production services - excellent maintenance and migration for network upgrades, underlay fail over - stats by user, as well as stats for underlay Why? ACK!! Hold it! We are doing it anyway. This is important.

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15 Multi Table Multi Level Multi Pipeline Fully Virtualized Multi Chassis QoS XC-12 Egress Scheduler Needs Full Visibility of input Queues Across the fabric! or else. Proper QoS Is impossible! XC-12 Port 2 Port 5: Egress Scheduler Port 2 Port 5: Egress Queue

16 Fixed Pipeline Small Table Un-Virtualizable Shallow Buffer QoS Munging White Box Scale Out Fabrics

17 Shameless Vendor Promotion The Only SDN Switch that combines: Internet Scale Multi Table OF 1.3+ Best In Class QoS ASIC that exceeds many high end routers Hardware Virtualization WITH QoS per Virtual Switch QoS Engineered Fabric for scale out expansion