T5_presentation

T5_presentation
POF
Protocol-Oblivious Forwarding
Towards OpenFlow 2.0
RB | 27.03.2015
OpenFlow 1.X
A Survey of Software-Defined Networking: Past, Present, and Future of
Programmable Networks (Figure 2)
The Evolution of OpenFlow
•
•
•
•
New Specifications at high rate
Reactive Evolution
Increased matching fields from 12 to
41
Need for more matching fields for
specific applications (e.g. Datacentre)
Version
Date
Header Fields
OF 1.0
Dec 2009
12 fields (Ethernet,
TCP/IPv4)
OF 1.1
Feb 2011
15 fields (MPLS, inter-table
metadata)
OF 1.2
Dec 2011
36 fields (ARP, ICMP, IPv6,
etc.)
OF 1.3
Jun 2012
40 fields
OF 1.4
Oct 2013
41 fields
P4: Programming Protocol-Independent Packet Processors (Table 1)
The Problem with OpenFlow 1.X
•
•
•
•
New OF Specifications at high rate
Hardware development cycle rate
much lower
Most OF Switches still run OF v1.0
OF table type pattern
New Service Required
OF Support?
No
Wait for new revision of OF
Specification
Wait for device support
Deploy the new service
Protocol Oblivious Forwarding: Unleash the Power of SDN through a
Future-Proof Forwarding Plane – SIGCOMM 2013 HotSDN Presentation
Yes
Towards OpenFlow 2.0
• New Services/Applications
– Demand for new Matching Fields
– Increasing Complexity of OF Instruction Set
• Trend to Programmable Switches
–
–
–
–
CPU/Software
Network Processors
FPGA
Flexible Match+Action ASICs
Protocol Independent Forwarding
•
•
•
•
Protocol Independence
Target Independence
Reconfigurability
Language Independence
“We believe that future generations of OpenFlow should allow
the controller to tell the switch how to operate rather than be
constrained by a fixed switch design” – Nick McKeown
P4: Programming Protocol-Independent Packet Processors
PIF - Initiatives
• P4 – Programming Protocol-Independent Packet Processors
http://www.p4.org/
• POF – Protocol-Oblivious Forwarding
http://www.poforwarding.org/
• ONF PIF – OpenSource Project
https://www.opennetworking.org/protocol-independent-forwarding
Protocol-Oblivious Forwarding
Protocol Oblivious Forwarding: Unleash the Power of SDN through a
Future-Proof Forwarding Plane – SIGCOMM 2013 HotSDN Presentation
PC Analogy
• Standard instruction set
• Intermediate level
abstracts the hardware
Protocol Oblivious Forwarding: Unleash the Power of SDN through a
Future-Proof Forwarding Plane (Figure 1)
POF Framework
• Flow Instruction Set
– Parsing, Editing, Forwarding
• Flow Instructions Blocks
– Flow Handling
• Several Northbound
Interfaces possible
Forwarding in Protocol-Oblivious Instruction Set (Figure 1)
POF – Flow Instruction Set
•
•
•
•
Concise set of instructions
Optimized for networking
applications
Platform independent
Protocol agnostic
Category
Instructions
EDITING
SET_FIELD, ADD_FIELD, DEL_FIELD, ALG,
CALCULATE_CHECKSUM,
SET_FIELD_UPDATE_CHECKSUM,
INC_FIELD, DEC_FIELD, OR_FIELD,
SRL_FIELD, SLL_FIELD, AND_FIELD,
XOR_FIELD, NOR_FIELD, NOT_FIELD
FORWARDING
GOTO_TABLE, COUNTER, OUTPUT,
GROUP, MOVE_PACKET_OFFSET,
SET_PACKET_OFFSET
ENTRY
SET_TABLE_ENTRY, ADD_TABLE_ENTRY,
DEL_TABLE_ENTRY
JUMP
BRANCH, COMPARE, JUMP
FLOW
SET_FLOW_METADATA,
GET_FLOW_METADATA,
ORDER_ENFORCE
Forwarding in Protocol-Oblivious Instruction Set (Table 1)
POF – Flow Instruction Set
•
•
•
•
•
Flow metadata
Flow table manipulation by data-path
Reuse of instruction blocks
Statistic counters are shared resources
Categorization of lookup tables
POF – Instruction Set
Is this an IP packet?
Data @{12B, 2B} = 0x0800?
Use destination IP to search
FIB
Extract Data @{30B, 4B};
Use it as key to search LPM
table x
Process TTL
Update Checksum
Conventional FE
Forwarding Flow
Decrement Data @{22B, 1B};
If result is 0, drop the packet
Use algorithm y to calculate
checksum over Data @{14B,
20B};
Write result @{24B, 2B}
POF Forwarding
Protocol Oblivious Forwarding: Unleash the Power of SDN through a
Future-Proof Forwarding Plane – SIGCOMM 2013 HotSDN Presentation
Characteristics of POF-FIS
• Flexibility
• Independence
– Northbound Interface
– Service and Application
• Completeness
– Same functionality as OpenFlow
Instead of hardcoded protocol fields, search key {offset, length}
Realization
• Controller based on Floodlight
• Two POF FE prototypes
– Huawei NE5000 core router platform
– Software-based FE
• Northbound-Interface
– CLI
– GUI
– High-Level Language Description
• Forwarding throughput reduction of up to 30%
Successful Transition
• OpenFlow Compatibility
– Incremental Deployment
• Forwarding Element Implementation
– New chips support POF natively
– Make existing chip support POF
Discussion
“As long as the performance is satisfactory, service providers will never
need to deal with vendors again after devices are deployed.”
“For instance, EDIT includes all packet editing related instructions we
believe ever needed, and FORWARDING and JUMP cover all the
common packet processing related instructions.”
“If one has sufficient understanding (…), he or she is able to design the
whole forwarding process by directly assembling the POF flow
instructions (…) without any compiler or interpreter.”
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