4.4 OpenFlow versions and feature evolution
4 min read•august 9, 2024
OpenFlow, the pioneering protocol in Software-Defined Networking, has evolved significantly since its inception. From basic packet matching and simple actions in version 1.0, it has grown to support complex network functions and advanced traffic management.
Each new version of OpenFlow has expanded its capabilities, introducing features like multiple flow tables, , and . These enhancements have made OpenFlow more flexible and powerful, enabling it to handle diverse network scenarios and emerging technologies.
OpenFlow Version Evolution
Key Milestones in OpenFlow Development
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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1 of 3
Top images from around the web for Key Milestones in OpenFlow Development
Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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Software Defined Network (SDN) and OpenFlow Protocol in 5G Network View original
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1 of 3
- introduced in 2009 marked the first standardized version of the protocol
- OpenFlow 1.0 defined basic (source/destination MAC addresses, IP addresses, and TCP/UDP ports)
- OpenFlow 1.0 supported simple actions (forward, drop, and modify packet headers)
- released in 2012 brought significant enhancements to the protocol
- OpenFlow 1.3 added support for multiple flow tables, allowing more complex packet processing
- OpenFlow 1.3 introduced group tables for implementing multicast and load balancing
- launched in 2014 represented a major update to the protocol
- OpenFlow 1.5 introduced egress tables for processing packets after they exit the switch pipeline
- OpenFlow 1.5 added support for stateful processing, enabling more advanced network functions
Protocol Capabilities Expansion
- OpenFlow 1.0 limited to 12 match fields for packet classification
- OpenFlow 1.3 expanded match fields to include MPLS labels and VLAN tags
- OpenFlow 1.3 introduced the concept of metadata, allowing information to be passed between flow tables
- OpenFlow 1.5 added support for packet registers, enabling more complex packet modifications
- OpenFlow 1.5 introduced the ability to match on TCP flags, improving traffic control capabilities
- Each version progressively increased the number of supported counters and meters
- OpenFlow 1.5 added support for egress port properties, allowing finer control over packet transmission
Advanced Pipeline Processing
Multi-Table Pipeline Architecture
- Multiple tables enable more efficient and flexible packet processing
- Packets traverse through tables in a predefined order, allowing for staged decision making
- Each table can have its own set of match fields and actions
- defines the action when no match is found (drop, send to controller, or next table)
- allows packets to be sent to a specific table for further processing
- Multiple tables support modular policy implementation, separating different network functions (access control, routing, QoS)
- Pipeline processing reduces the total number of required compared to single-table implementations
Group Table Functionality
- Group tables introduce advanced forwarding abstractions in OpenFlow
- Group tables consist of group entries, each containing a list of action buckets
- Four types of group tables: all, select, indirect, and fast failover
- All group type executes all action buckets, used for multicast or broadcast forwarding
- Select group type executes one bucket based on a selection algorithm, enabling load balancing
- Indirect group type executes the single defined bucket, providing a level of indirection
- Fast failover group type executes the first live bucket, enabling quick fault recovery
- Group tables support complex actions like link aggregation and multipath routing
- Group tables can be referenced by flow entries, allowing for reusable action sets
Traffic Management Features
Advanced Metering Capabilities
- Metering enables rate-limiting and prioritization of traffic flows
- contain , each specifying a rate and a set of
- Bands define actions to take when traffic exceeds specified rates (drop, dscp remark)
- Meters can be applied to individual flows or groups of flows
- OpenFlow 1.3 introduced , allowing fine-grained traffic control
- OpenFlow 1.5 added support for meter statistics, enabling better monitoring of traffic patterns
- Metering supports implementation of policies in OpenFlow networks
Enhanced Protocol Support
- added in OpenFlow 1.2, expanded in later versions
- include source and destination addresses, flow label, and ICMPv6 type/code
- OpenFlow 1.3 introduced full support for
- OpenFlow 1.4 added support for , enabling SDN in optical networks
- OpenFlow 1.5 introduced support for , improving traffic classification capabilities
- Later versions added support for new protocols (SCTP, GRE, VXLAN) expanding use cases
Extensible Match Framework
- allows for flexible packet classification beyond predefined fields
- introduced in version 1.2 enables vendor-specific match fields
- OXM allows for future protocol support without requiring OpenFlow protocol updates
- Extensible match supports matching on arbitrary packet header fields and payload data
- used for extensible match fields, providing flexibility and efficiency
- Extensible match enables OpenFlow to adapt to new network protocols and technologies
- Custom match fields can be defined for specific network applications or environments
Key Terms to Review (36)
Backward Compatibility: Backward compatibility refers to the ability of a system, such as software or hardware, to work with previous versions of itself or with products designed for earlier standards. This feature ensures that new updates or versions do not disrupt existing systems and allows users to gradually transition without losing functionality. It is particularly crucial in evolving technologies like networking protocols, as it helps maintain interoperability across different versions.
Bands: In the context of networking, bands refer to frequency ranges allocated for wireless communication, which can significantly influence the performance and capabilities of networks, including those utilizing protocols like OpenFlow. The evolution of these bands is critical as it impacts the way data is transmitted and the efficiency of network management across different OpenFlow versions.
Control plane: The control plane is a fundamental component of network architecture responsible for managing and directing network traffic by controlling the flow of data packets through the network. It separates the decision-making process from the data forwarding process, allowing for more dynamic and efficient network management and enabling features like programmability and automation.
Data Plane: The data plane is the part of a network that carries user data packets from one point to another. It operates on the forwarding of data based on rules set by the control plane, managing how packets are transmitted and processed through the network infrastructure.
Extensible match support: Extensible match support is a feature in OpenFlow that allows for the specification of various fields in packet headers for matching purposes, enabling more flexible and granular traffic management. This capability supports the evolution of network management by allowing new types of matches to be added without requiring changes to the core protocol, thus facilitating enhanced network control and adaptability as networking needs grow.
Extensible matching: Extensible matching is a flexible and dynamic method used in network protocols, particularly within the OpenFlow architecture, that allows for the creation of complex matching rules based on various packet header fields and metadata. This approach enables network operators to tailor their traffic management strategies by easily extending or modifying matching criteria as new needs or technologies emerge. As OpenFlow has evolved, extensible matching has become essential for supporting diverse applications and policies, enhancing overall network efficiency and performance.
Flow entries: Flow entries are data structures used in Software-Defined Networking (SDN) that define how packets should be processed as they traverse a network switch. They include important information such as match fields, actions to take on matching packets, and counters to track statistics. Flow entries are essential in determining the behavior of network traffic by enabling switches to make intelligent decisions based on the defined rules.
Goto-table action: A goto-table action is a fundamental mechanism in the OpenFlow protocol that directs packets to a specific flow table based on the matching criteria defined in the flow entries. This action allows for greater flexibility and control in network traffic management, enabling more complex decision-making by the controller as it processes packets. By using goto-table actions, network devices can efficiently handle different types of traffic and apply different processing rules without needing to revert back to the controller for every packet.
Group Tables: Group tables are a feature in OpenFlow that allow for the management of groups of actions to be applied to packets. This mechanism enables more complex operations and the ability to execute multiple actions in a single rule, enhancing the flexibility and efficiency of network management. They evolve as part of OpenFlow’s development, contributing to advanced functionalities such as load balancing and traffic engineering.
IETF: The Internet Engineering Task Force (IETF) is an open organization responsible for developing and promoting voluntary Internet standards, particularly in the field of networking protocols. It plays a crucial role in shaping the direction of networking technologies, including key protocols like TCP/IP, and standards for Software-Defined Networking (SDN) that support interoperability and enhance the evolution of network architecture.
Ipv6 match fields: IPv6 match fields are specific criteria used in network switches that utilize the OpenFlow protocol to identify and process IPv6 packets. These fields enable devices to inspect various aspects of IPv6 headers, such as source and destination addresses, traffic class, and flow label, allowing for fine-grained control over traffic routing and policy enforcement. By incorporating IPv6 match fields, networks can leverage the capabilities of the latest Internet Protocol version to enhance performance and functionality in Software-Defined Networking environments.
Ipv6 support: IPv6 support refers to the ability of network devices, protocols, and applications to operate using Internet Protocol version 6, which is designed to replace IPv4 due to the exhaustion of available IPv4 addresses. This support is essential for ensuring that OpenFlow can effectively manage modern networks that are increasingly reliant on a growing number of devices connected to the Internet, each requiring unique IP addresses.
Latency reduction: Latency reduction refers to the process of decreasing the time delay experienced in data transmission across a network. In the context of software-defined networking, latency reduction is crucial as it enhances the efficiency and performance of data flow, leading to improved responsiveness for applications and services. Reducing latency helps optimize bandwidth utilization and supports real-time communication, making it an essential aspect of network design and management.
Match fields: Match fields are key components in the OpenFlow protocol that specify criteria for matching packets against rules in flow tables. These fields allow switches to identify and process network traffic based on specific attributes, such as source and destination IP addresses, MAC addresses, and transport layer protocols. The flexibility of match fields enables efficient traffic management and facilitates the implementation of complex networking policies.
Meter Entries: Meter entries are specific components within the OpenFlow protocol that define how traffic is measured and controlled in a network. These entries allow for the implementation of quality of service (QoS) by enabling traffic management features such as bandwidth limits, rate shaping, and traffic prioritization, which evolve across different versions of OpenFlow to enhance network performance and flexibility.
Meter tables: Meter tables are data structures used in OpenFlow to manage and store metering information for network flows. These tables define how traffic is measured, including bandwidth usage and rate limits, which helps in monitoring and controlling network performance. Meter tables are essential for implementing Quality of Service (QoS) policies and allow for more granular control over the flow of data across a network.
Metering Capabilities: Metering capabilities refer to the ability of a network to measure, monitor, and manage the flow of data traffic in a Software-Defined Networking (SDN) environment. This involves tracking the amount of data transmitted through various network paths, which aids in understanding bandwidth usage and implementing quality of service (QoS) policies effectively. As SDN evolves, metering capabilities have become essential for dynamic resource allocation, traffic engineering, and enhancing overall network performance.
MPLS Label Stacking: MPLS label stacking is a method used in Multiprotocol Label Switching (MPLS) networks where multiple labels are applied to packets for better routing and traffic engineering. This technique allows for more granular control of data paths through the network, enabling features like traffic segregation and improved bandwidth utilization. By stacking labels, a single packet can carry information for different services or flows, enhancing the efficiency of packet processing and forwarding.
Open Networking Foundation: The Open Networking Foundation (ONF) is a non-profit organization that promotes the adoption of open software-defined networking (SDN) and related technologies. It aims to drive innovation through collaboration among various stakeholders in the networking ecosystem, ensuring interoperability and advancing the SDN paradigm. By creating open standards, the ONF supports the development of SDN solutions and fosters a community around platforms like OpenDaylight and ONOS, as well as evolving OpenFlow specifications.
Open vSwitch: Open vSwitch is an open-source virtual switch designed to enable network automation while supporting standard management interfaces and protocols. It acts as a software-based switch that can manage traffic between virtual machines and physical networks in a Software-Defined Networking environment. This flexibility makes it crucial for integrating with various SDN controller platforms and adapting to evolving OpenFlow standards.
OpenFlow 1.0: OpenFlow 1.0 is a foundational protocol in Software-Defined Networking (SDN) that allows the separation of the control plane from the data plane in networking devices, enabling centralized management of network resources. This version marked the beginning of the OpenFlow protocol's evolution, providing essential features such as flow tables and the ability to manage network traffic dynamically. Understanding OpenFlow 1.0 is crucial for grasping how SDN architecture operates and how subsequent versions have expanded its capabilities.
OpenFlow 1.3: OpenFlow 1.3 is a widely-used standard protocol within Software-Defined Networking (SDN) that allows for the programmable control of network devices such as switches and routers. This version brought significant enhancements over its predecessors, including support for additional features like group tables, better packet handling capabilities, and support for IPv6, enabling more complex and flexible network management and programmability.
OpenFlow 1.5: OpenFlow 1.5 is a version of the OpenFlow protocol, which is an essential component of Software-Defined Networking (SDN) that enables the separation of the control plane and data plane in network devices. This version builds on previous iterations by introducing new features that enhance its capabilities, such as improved support for network virtualization and better handling of complex flow management. These enhancements align with the evolving needs of SDN architecture, making OpenFlow 1.5 a crucial standard for managing and orchestrating networks more efficiently.
OpenFlow Extensible Match (OXM): OpenFlow Extensible Match (OXM) is a flexible match field structure used in OpenFlow protocol that allows for dynamic specification of match criteria for packet processing. It provides a way to extend the range of fields that can be matched on beyond the basic set defined in earlier versions of OpenFlow, accommodating newer protocols and use cases as the networking landscape evolves.
Optical Port Properties: Optical port properties refer to the characteristics and functionalities of ports that facilitate optical communication within network devices. These properties define how light signals are transmitted, received, and processed, affecting the performance and efficiency of data flow in a network. Understanding these properties is crucial as they relate to the evolution of protocols like OpenFlow, which has adapted to better handle optical technologies in networking.
Packet-in messages: Packet-in messages are a type of communication used in Software-Defined Networking (SDN) frameworks, specifically in OpenFlow, to inform the controller about packets that have been received by a switch but could not be handled locally. These messages play a critical role in enabling the controller to make dynamic decisions about packet forwarding and network behavior. They signify the interaction between the data plane and the control plane, facilitating network management and optimization.
Packet-out messages: Packet-out messages are a crucial component in the OpenFlow protocol, utilized for sending packets from a controller to a switch, enabling customized handling of network traffic. These messages allow the controller to specify how packets should be treated, which can include actions like forwarding them to specific ports or modifying packet headers. This functionality is vital as it helps in controlling and managing network flows effectively, reflecting the evolution and enhancements of the OpenFlow protocol over different versions.
Per-flow metering: Per-flow metering is a technique used in networking to monitor and collect statistics on individual data flows within a network. This method enables more granular analysis of network traffic, allowing for better resource allocation, performance monitoring, and anomaly detection. By focusing on specific flows rather than aggregated data, per-flow metering enhances the ability to make informed decisions regarding traffic management and quality of service.
Quality of Service (QoS): Quality of Service (QoS) refers to the ability of a network to provide different priority levels to different types of data, ensuring a certain level of performance for applications. This concept is critical for managing network traffic, as it helps prioritize important data flows, manage bandwidth allocation, and minimize latency or packet loss. QoS plays a key role in various contexts like packet forwarding techniques, traffic optimization strategies, and is essential for service providers and data centers to meet user demands.
Scalability concerns: Scalability concerns refer to the challenges and limitations associated with expanding a network's capacity to accommodate growth without sacrificing performance or efficiency. In the context of networking technologies, particularly with the evolution of OpenFlow, scalability concerns arise as networks need to adapt to increasing numbers of devices, users, and applications while maintaining manageable complexity and operational costs.
SDN Controllers: SDN controllers are the central components in Software-Defined Networking that manage and orchestrate network resources and policies. They serve as the communication bridge between the software applications and the underlying hardware infrastructure, enabling dynamic configuration, monitoring, and management of the network. SDN controllers play a crucial role in simplifying network management, enhancing automation, and facilitating innovations like OpenFlow, which has evolved through various versions to support more features and functionalities.
Support for multiple tables: Support for multiple tables refers to the capability of a networking protocol to maintain and manage more than one flow table within a device, such as a switch. This feature enhances the flexibility and efficiency of packet processing, allowing for different types of traffic or policies to be applied simultaneously without interference. Multiple tables enable more advanced functionalities like better traffic engineering, prioritization, and support for complex applications that require distinct handling of various flows.
Table miss flow entry: A table miss flow entry is a type of entry in a flow table that defines how to handle packets that do not match any existing flow entries. When a switch encounters a packet that doesn't match any rules, it checks for a table miss entry to determine the appropriate action, which could include sending the packet to the controller or dropping it. This concept is crucial for dynamic packet handling in Software-Defined Networking, enabling efficient communication between switches and controllers.
Tcp flags matching: TCP flags matching refers to the process of identifying and filtering TCP packets based on specific control flags set in the TCP header, such as SYN, ACK, FIN, and RST. This matching is crucial for managing the state of TCP connections and implementing rules in network protocols like OpenFlow, enabling finer control over traffic handling and flow management.
Tlv (type-length-value) format: The tlv format is a data encoding scheme that encodes information in three components: a type identifier, a length field, and a value field. This structure allows for the flexible and extensible representation of various data elements, making it particularly useful in network protocols and data serialization. In the context of OpenFlow, the tlv format helps manage different features and versions by enabling the efficient transmission and parsing of information across diverse network devices.
Vendor-neutrality: Vendor-neutrality refers to the principle of designing systems or standards in a way that they are not tied to any specific manufacturer or supplier. This concept is crucial for ensuring interoperability and flexibility, allowing users to choose from various vendors without being locked into a single provider's ecosystem. In the context of evolving technologies like OpenFlow, vendor-neutrality supports innovation and competition by promoting open standards that different vendors can implement.