SDN-enabled Data Center Bridging Demo from Ethernet Summit 2013

1. SDN Enabled DCB Configuration
Elastic QoS by Controlling Link Level DCB Primitives
Dell Enterprise Service Group
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2. Office of the CTO2
Agenda
• What is DCB?
• Problems
• SDN Advantage
• Use Cases
• Demo

3. Office of the CTO3
Data Center Bridging (DCB)
• DCB Definition
• Ethernet Enhancement for data centers
• Best Effort  Lossless-ness
• Convergence: Running Fiber Channel over Ethernet
• Primitives
• Priority Flow Control (PFC) – IEEE 802.Qbb
• Enhanced Transmission Selection (ETS) – IEEE 802.Qaz
• Congestion Notification (CN) – IEEE 802.1Qau
• Control
• DCB-Exchange Protocol (DCBX)
• New TLV Fields in LLDP
• Peer2Peer (Port Level)

4. Office of the CTO
Bandwidth
Allocation in
Egress Queues
70%
20%
10%
Ingress
Traffic Types
by dot1p
Priorities
ETS Priority
Groups:
LAN: 0,1,2,5,6,7
SAN: 3
IPC: 4
10
GigE
4
Link Level Primitives
• Priority Flow Control
• Receiving station sends Pause Frames
• Uses well-known Multi-cast MAC
• Quanta – Num of 512 bits to wait
• Enhanced Transmission Selection
• Assign priorities to application classes
• Manage traffic priority to the app
• Allocate bandwidth to the classes
• Congestion Notification
• L2 End-to-End Cong. Notification
• Requires Enabling on entire data-path
• Switches in-patch can send CN frames
Receive
Buffers
PFC Pause
Frame sent
only for
Priority 3
Traffic
Dot1p
Priorities
as Virtual
Transmit
Queues
7
6
5
4
3
2
1
0
10
GigE
1
2
3
4
2Gbps
2Gbps
2Gbps
1GbpsCN

5. Office of the CTO5
Problems
• Configuration Issues
• Static Port to Port – Multihop is complex
• DCBX-TLVs carry config params
• DCBX unsupported on end-hosts
• Interoperability Issues
• Not Uniformly Implemented
• QCN not required for PFC/ETS
• Hence DCB perceived confusing
• Inflexible and Non-Scalable
• DCB capabilities may be sparse
• Wasted Switch Resource if Unused
• Associated only with Storage
Legacy Config
X
X
Legacy Config
X X
Legacy Config

6. Office of the CTO6
SDN Advantage
• Centrally Program/Configure Primitives
• Removes need for DCBX
• Supports End host Config
• Eliminate Willing/Non-Willing Modes
• Interoperability Simplified
• Heterogeneous Friendly
• Switches advertise capabilities
• Actively Probe, Verify and Configure
• Flexible and Scalable
• Dynamically Reconfigure Paths
• Optimized use of resources
• New QoS functions – Lossless Paths
Legacy ConfigSDN Controller
Legacy ConfigSDN Controller
Legacy ConfigSDN Controller

7. Office of the CTO
• Simplify and Enable Multi-Hop Environments
• Move Data effortlessly between SANs
• Lossless-QoS For Granular Flows in Multi-Tenant
Environments
• Prioritize SQL query on iSCSI for RED over BLUE
• …Over Email Backup on iSCSI SAN 2 for BLUE-Tenant
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Use Cases

8. Office of the CTO
Demo
8
• Demo Setup
• How we test/tools etc.
• Verification

9. Office of the CTO9 Confidential
Demo Setup
Stack Diagram Demo Topology
App
(Elastic DCB)
OF-Controller
(POX Modified)
OF-Switch
(DCB Extensions)
OFPT_PORT_MOD
Extensions
Ethernet Ports
Program DCB
Primitives
pssh
iperf
clients
iperf
server

10. Office of the CTO
Sample DCB Configuration
• DCB Configuration Profile 1
• ETS
ets tc_tx_bw: 90 10 0 0 0 0 0 0
ets tc_rx_bw: 90 10 0 0 0 0 0 0
ets tc_tsa : 2 2 0 0 0 0 0 0
ets prio_tc : 0 1 2 0 0 0 0 0
• Demo Instruments Few Such Profiles
• ETS
ets tc_tx_bw: 90 10 0 0 0 0 0 0
ets tc_tx_bw: 70 30 0 0 0 0 0 0
ets tc_tx_bw: 50 50 0 0 0 0 0 0
ets tc_tx_bw: 30 70 0 0 0 0 0 0
ets tc_tx_bw: 10 90 0 0 0 0 0 0
90% B/W* on P0 Traffic1
10% B/W* on P1 Traffic
*Minimum Guarantee
TSA – transmission
selection algorithm
ETS – priority 0 and 1

11. Office of the CTO11 Confidential
Applying Profile 1, Different Tests

12. Office of the CTO12 Confidential
Summary
• DCB Primitives via SDN/OpenFlow
• Eliminated need for DCBx
• Created New QoS/Classes