Protocol Oblivious Forwarding Unleash the Power of SDN

Protocol Oblivious Forwarding: Unleash the Power of SDN through a Future-Proof Forwarding Plane Haoyu Song Networks Business Unit, Technology Strategy, IP Research Huawei Technologies, USA HUAWEI TECHNOLOGIES CO. , LTD. www. huawei. com

What Happened to Your Mobile Phone: A Metaphor Past l l l Now Preloaded with all the features Get new models for new apps No way to customize l l l Download only the apps you need New features in new software release Write your own apps Decoupling the platform and the apps is the key for smart phone’s success. The real value exists in services provided by software. Better hardware can carry and deliver the value better. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 2

Network Device Programming Models I can only use the device as- is. Data Plane Device Vendor-driven Programmability Closed and proprietary design that meets the pre-defined service requirements HUAWEI TECHNOLOGIES CO. , LTD. Control Plane Program “Black Box” Control Plane I can do whatever I want. Control Management Control Plane I can do what the device has supported. Open. Flow 1. x Open. Flow+ “Gray Box” Data Plane “White Box” Data Plane Device Vendor/Service Provider-driven Provider Split Programmability Open interface using existing technology building blocks for limited programmability Huawei Confidential Open interface using generic network programming model, enabling full programmability 3

Current Open. Flow-enabled Device is a “Gray Box” New service required Yes No Wait for new revision of OF Spec. Wait for the device upgrade to support the new spec. Ideal path Does the OF Spec. support it? Deploy the software to enable the service l l l Plane coupling Protocol/instruction explosion Stateless/Limited expressivity l l Not future-proof Slow innovation process Protocol-specific semantics forces the forwarding elements (FE) to understand the packet formats and retain the specific packet processing knowledge. The reactive evolving path needs incessant standard revisions to accommodate new features and new protocols. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 4

SDN: Operate your Network Device like a PC l l l Simple & generic instruction set Ultimate flexibility & extensibility Upgrade only on performance Service Application API Sys. Call Operating System Controller Driver Instruction Set Forwarding Element CPU system Peripheral SDN Computer System Computer system components have been decoupled from the vertical integration model. SDN is on the track to mimic this transition. But current Open. Flow still doesn’t embrace this model to the full extent. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 5

Protocol Oblivious Forwarding: Core Concept l l l Table search keys are defined as {offset, length} tuples Instructions/Actions access packet data or metadata using {offset, length} tuples Include other math, logic, move, branching, and jump instructions Match ~40 matching header fields defined yet still many uncovered protocols/headers {offset, length} covers any frame based formats Action OFPAT_COPY_TTL_OUT OFPAT_COPY_TTL_IN OFPAT_SET_MPLS_TTL OFPAT_DEC_MPLS_TTL OFPAT_PUSH_VLAN OFPAT_POP_VLAN OFPAT_PUSH_MPLS OFPAT_POP_MPLS OFPAT_SET_NW_TTL OFPAT_DEC_NW_TTL OFPAT_PUSH_PBB OFPAT_POP_PBB and on … POFAT_SET_FIELD POFAT_ADD_FIELD POFAT_DELETE_FIELD POFAT_MOD_FIELD Period. Current Open. Flow POF Packet field parsing and handling are abstracted as generic instructions to enable flexible and future proof forwarding elements. This is simple yet has profound implications to SDN. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 6

How to Ask a Dumb FE to Do Smart Things l The fine-grained bit-level manipulations used to be hardcoded or micro-coded in the FE are now explicitly described by controller Is this an IP packet? Data @ {12 B, 2 B} = 0 x 0800? DMAC Use destination IP to search FIB Extract Data @ {30 B, 4 B}; Use it as key to search LPM table x Process TTL Decrement Data @ {22 B, 1 B}; If result is 0, drop the packet Update Checksum Clear Data @ {24 B, 2 B}; Use algorithm y to calculate checksum over Data @ {14 B, 20 B}; Write result @ {24 B, 2 B} Conventional FE Forwarding Flow POF Forwarding Flow SMAC Type Payload FCS Ethernet/IPv 4 Packet Format Open. Flow’s high level semantics (“what”) is simple in communication but demands forwarding plane intelligence; POF’s low level semantics (“how”) moves all the intelligence up to the controller HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 7

Other POF Features to Enhance Open. Flow l Enable active & stateful data-path • Add general flow-based metadata beyond counters Statistics • Time stamps • Anomaly • Flow states • • Add key metadata instructions Flow Entry data-path instructions that can create and modify flow tables MAC learning • Active firewall • Dynamic load balancing • Controller offloading • Instruction Execution Module Table Update Flow Table Search The flow metadata and data-path table manipulation instructions enrich the forwarding plane programmability and flexibility HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 8

Other POF Features to Enhance Open. Flow (cont’d) l Add entry-specific parameters and allow multiple flow entries share the same instruction block • Save instruction memory and enable fast updates l Treat statistics counters and flow metadata as shared resource pool and assign the resource to flow entries on demand • Aggregated and multi-purpose counters for statistics • Message communication vehicle for flows l Distinguish logical tables and physical tables • The same physical table used by multiple logical tables (e. g. IP/RPF, MAC Learning/forwarding) • One physical table resource shared by multiple unrelated logical tables (e. g TCAM, Hash) These new features facilitate the efficient hardware implementation, otherwise it would be difficult or even impossible for FE to figure out the optimization opportunities. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 9

POF-based SDN Architecture Novel Applications &Services Protocol Specific Application Programming Languages Application API Flow Instruction Set Controller Hardware Abstraction Layer • Programmable • Network optimized Flex Flow Processor POF Instructions CPU • Runtime & Remote ASIC POF Data Path reprogrammable • Table driven & protocol blind • High • Flow instruction set performance HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 10 Driver • • Flexible Generic Standard Low level instruction set Forwarding Elements NPU Open. Flow+ Flow Tables Controller Compiler Protocol Agnostic Tables/Instructions

POF System Prototypes Forwarding Elements Controller HUAWEI Core Router POFSwitch MPU Switch Control Module Open. Flow Connection Management POFGUI Protocol Oblivious Forwarding Open. Flow Parse Bypass Manager Module Open. Flow Encap LPU Open. Flow Parse POFManager Open. Flow Connection Management Open. Flow Encap Resouce Module Resouce of POFSwitch Floodlight Provider (Controller) HAL of POF Forwarding Engine Driver PMDatabase l l Datapath Module Other OFMessage Process Modules Forwarding Engine Based on Floodlight with POF extension Open source, cross platform, Apache licensed, and Javabased software HUAWEI TECHNOLOGIES CO. , LTD. l l Forwarding Engine NP-based hardware implementation on NE 5000 E or NE 40 E router platform Open source software switch on Linux server Huawei Confidential 11

Using NPU to Implement POF l Proprietary NPU runs in RTC (Run To Completion) programming model l Two modes for POF implementation • Function Mode: Each FIS instruction is implemented in FE NPU as a function written in micro-code. Each instruction is essentially a function call. • • Simple but has a performance hit Compiling Mode: Controller or the FE driver compiles the FIS instructions into NPU microcode directly and load the code to the program memory. • l Better performance but more complex Current prototype used Function Mode and we are working on Compiling Mode • We see up to 30% performance loss • • Mainly due to table search key constructions Still satisfy typical application scenarios for the 40 G line card It is feasible to use NPU to implement POF, in the long run we prefer to have some POF-optimized silicon to reduce the cost and boost the performance. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 12

POF Use Cases Forwarding Protocol Enabling User Defined Source Routing NDN CCN SCN … NVGRE VXLAN TRILL IPX Fibre Channel … L 2 IPv 4 IPv 6 MPLS … Network Service Enabling VPLS, Stateful Firewall, DPI, L 4~L 7 Applications Other innovation possibilities Network processing simplification - reduce tunneling and transformation User defined scratch space in packets for in-band info communication (OAM) POF offers unmatched flexibility to the forwarding plane. With it, we can either deploy sophisticated network services or greatly simplify the network forwarding process. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 13

How to realize POF l Define low-level instruction set FIS • • Platform-independent generic primitives Expressive for a wide range of applications Programming in “assembly” style Allows layered abstraction and virtualization • l No need to be the same as the chip instruction set Standardization is the key • • Stabilize a future-proof Open. Flow specification (Open. Flow 2. 0? ) Need industry-wide collaboration involving all the player • • www. poforwarding. org Many hard problems (technical and non-technical) to attack We publish the open-source website to advocate open research and encourage contributions and adoptions • POF has the potential to truly commoditize the forwarding elements while nourishing an independent controller/application software market. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 14

Conclusions l POF thoroughly decouples the SDN control plane and the forwarding plane • Controller-side software can construct flexible applications without any underlying constraints • Controller applies high level languages and compilers to program the FEs through the standard instruction set l l POF advocates a standard, flexible and future-proof forwarding plane • Allow FEs to focus on performance rather than functionality • FE will become simpler and more flexible POF calls for continuous research to improve • Standardize the interface and the FIS, leave the other details for innovation Service providers will benefit from this technology through: (1) using standard, simple, and future-proof FEs to save CAPEX/OPEX (2) quickly deploying customized and innovative services in the form of application software to generate new revenues. HUAWEI TECHNOLOGIES CO. , LTD. Huawei Confidential 15

Thank you www. huawei. com Copyright© 2013 Huawei Technologies Co. , Ltd. All Rights Reserved. The information in this document may contain predictive statements including, without limitation, statements regarding the future financial and operating results, future product portfolio, new technology, etc. There a For more information, please go to www. poforwarding. org and number of factors that could cause actual results and developments to differ materially from those expressed or subscribe ONF SDN-Future Discussion Group mailing list. implied in the predictive statements. Therefore, such information is provided for reference purpose only and constitutes neither an offer nor an acceptance. Huawei may change the information at any time without notice.