Huawei Agile Network: A Solution for the Three Major Problems Facing Traditional Networking
By Ma Yun, Vice President of Huawei Enterprise Networking Product Line
Bottlenecks in Traditional Networking
The Internet is developing at a rate that outpaces all existing data networks in both speed and scale – except for perhaps the rate at which Internet service innovation is occurring. As the variety of real-time services continue to develop, including video and audio, cloud data center, and mobile services, bottlenecks can form that prevent traditional networks from delivering expected service quality. In this environment, traditional networks face three problems:
• Lack of user experience guarantees: Most IP networks are connectionless, providing only minimum bandwidth service quality. The lack of quality controls for delivered services results in situations that thwart user expectations for a quality experience and impacts customer relationships.
• Inefficient service deployment: In traditional networking, services and networks are deployed separately. Most networks are configured using commands or network management systems. These networks are essentially static and inefficient at deploying dynamic services that require timely adjustments. In extreme cases, these networks may even fail to support such services.
• Slow adaptation to new services: It may take years for traditional networks to upgrade features, adjust architectures, or introduce new devices to meet new service requirements. For example, the traditional Layer 2 VLAN mechanism of a cloud data center with virtual machines and virtual networks is required to run new bearer protocols on switches to meet scalability requirements; however, the physical devices involved cannot adapt to these requirements quickly enough. In this situation, software-defined virtual switches and Virtual Extensible Local Area Network/Network Virtualization Generic Routing Encapsulation (VXLAN/NVGRE) overlay networking can bypass the limitations of physical switches and still satisfy the scalability requirements of the network.
Over the years, many solutions have been proposed to solve the problems facing traditional networks. As is often the case, when one problem is solved, another one crops up. The nature of traditional networking determines the decoupling between networks and services (represented by IP and Ethernet services). Networks and services are transparent to each other. This decoupling mode enables rapid Internet service innovations, but creates a barrier between networks and services. The problems facing traditional networking cannot be solved without focusing on the fundamental design of network infrastructure.
SDN Industry Conundrums
SDN was proposed as the answer to problems with IP network architecture and to support future network growth. The scope of SDN, however, has constantly shifted since the original proposals. The characteristics of SDN technologies as understood by the networking industry can be summarized as follows:
• Centralized control architecture: An SDN characteristic first put forward by the Clean Slate project team, this architecture removes the control functions from IP network devices and moves them into a logically separate server, called the controller. In this architecture, network devices forward traffic based on the control data delivered by the controller. The controller requires no direct knowledge of the network architecture. The Open Network Foundation (ONF) currently sponsors this architecture and the control protocol is called OpenFlow. However, the IETF and some equipment vendors believe that traditional device control protocols, such as Network Configuration Protocol (NETCONF), Command Line Interface (CLI), Simple Network Management Protocol (SNMP), Path Computation Element Protocol (PCEP), and the latest, Internet Routing System (IRS), are already sufficient to meet the requirements for centralized control and this function should be inherited. An architecture that separates forwarding from control cannot be equated with OpenFlow because OpenFlow is merely a control option.
• Open network capabilities: This SDN characteristic provides additional benefits. The core concept involves packaging network capabilities into an operating-system-like controller. In this architecture, upper-layer applications and services obtain network capabilities through APIs at the controller, thereby closely integrating services and networks. There are currently two open network capability standards: a network-specific plug-in interface and Quantum API defined by OpenStack, and a device-specific OpenFlow interface defined by ONF. Because APIs defined in these two standards cannot apply to all network applications, equipment vendors have gradually developed their own APIs.
• Overlay and network function virtualization: Virtual network devices in data centers, such as vSwitch, vRouter, and vFirewall, can be regarded as virtualized server resources. The universal server virtual machine platform uses software to simulate traditional device functions, breaking through the limitations posed by Application-Specific Integrated Circuits (ASICs) used by traditional devices. As a result, the virtual machine platform can provide flexible device capabilities, facilitating new service deployment and management.
The preceding three characteristics, although all are called SDN characteristics, are loosely related and can be implemented separately. When discussing SDN, different organizations may focus only on a single SDN characteristic, which may explain why SDN is perceived as confusing and controversial.
Huawei Agile Network: Adapting Networks to Services
Huawei has launched the Agile S12700 Series, the industry's first Agile Network Architecture, SDN-ready switches. Huawei Agile Network provides a highly adaptive network architecture that resolves the three major problems facing traditional networking – lack of user experience guarantees, inefficient service deployment, and slow adaptation to services. Furthermore, it lays the foundation necessary to establish quality-focused and efficient networks for customers. Huawei Agile Network architecture inherits the SDN industry's latest achievements as well as Huawei's extensive experience deploying efficient and high-quality networks over the past 20 years.
The Huawei Agile Network architecture consists of three layers: the device layer, the control layer, and the management orchestration layer. Physical Huawei devices and virtual machines running on the hypervisor (the virtual machine monitor) reside on the device layer. The controller resides on the control layer. The management orchestration layer controls the entire network to implement end-to-end service deployment. The three layers provide abstracted device, network, and service capabilities, respectively, through independent, open APIs that meet the programming needs of different user levels. Currently, three Huawei Agile Network-architecture-based solutions are available: Cloud Data Center, Efficient WAN, and Agile Campus.
To eliminate the problems facing traditional networking, Huawei Agile Network adds three new mechanisms to the centralized control, open network capabilities, and network function virtualization characteristics common to SDN: full programmability, a service-friendly architecture, and smooth evolution from traditional networks. These three new mechanisms enable Huawei Agile Network to quickly respond to cloud and mobile service deployments and to facilitate fast programming for new services as well. In addition, the new mechanisms allow Huawei Agile Network to quickly identify and locate factors affecting the user experience, enabling efficient fault location and prompt adjustments to ensure network quality.
● Fully Programmable Network: Software-Defined Flexibility with Hardware Performance
"Software-defined" mechanisms are at the core of SDN. These mechanisms enable networks to quickly and flexibly implement new service requirements and innovations. In practical terms, SDN's central control and open network capabilities cannot be applied to all existing networks. In the forwarding plane of physical devices, fixed ASICs cannot be reprogrammed, thereby limiting the deployment of future services. In response, Huawei has developed a low-cost, high-throughput programmable Ethernet Network Processor (ENP) chip to break the restrictions of fixed ASICs. vSwitches and vFirewalls in Overlay Mode provide device capabilities by means of server virtualization. The ENP chip enables the forwarding and control planes to be fully programmable. Huawei Agile switches maintain the high forwarding speeds of hardware switches and still provide software-defined flexibility, high performance, low power consumption, and low-cost switch forwarding.
● Service-Friendly Architecture
In traditional networking, the separation of services from networks prevents basic mechanisms to guarantee a quality user experience. Continuous and discontinuous quality deterioration remain a constant headache. After years of research, Huawei has developed the Packet Conservation Algorithm for Internet (iPCA) technology to solve the user experience guarantee problem in IP networks. This technology provides a proactive quality detection mechanism for traditional networks, which enables real-time quality detection and prompt fault location. The inspiration behind this technology is packet detection and quality assurance. By globally ensuring the quality of each packet, the quality of the entire service is ensured. This technology differs from traditional connection-oriented quality detection technologies in that it preserves the advantages of connectionless IP networks while enabling the quality assurance measures previously only available in traditional connection-oriented (such as switch-based) environments.
The iPCA technology applies not only to IP networks, but also to other connectionless networks, such as Ethernet. This technology fundamentally improves the user experience and fault location efficiency of traditional networks.
● Smooth Evolution
SDN paints a bright future for networks, but there is still a long way to go before mature SDN technologies and architectures become practical for large-scale deployment. Can we enjoy the benefits of SDN today while preparing existing networks for a smooth transition to comprehensive SDN architectures? Huawei's answer is "yes" – with the SDN strategy of "smooth evolution."
By leveraging its mature network technologies and architectures, including the newly-developed ENP chip and iPCA technologies, Huawei is already providing customers with many core SDN benefits, such as efficient and dynamic service deployment, quick adaptation to new services, and powerful user experience guarantees. What's more, transitioning to the SDN architecture of the future will require only a simple upgrade to device software. The separate controller architecture available today can easily be upgraded to Huawei Uni-Controller architecture in the future. With this controller architecture, Huawei can help customers build multi-tenant cloud data centers, provide efficient WAN link optimization solutions, and build agile campus networks centered on wireless, security, cloud, and video services without the wait.
● Adaptable Product Innovation
Huawei's smooth-evolution SDN architecture is the result of a handful of core innovations. The first innovation is agile switches. ENP chip technology enables switches to adapt to almost any future service or protocol, including potential OpenFlow upgrades.
The second innovation is the Huawei controller technology, which includes the Cloud Controller for data centers, Campus Controller for campus networks, and WAN Controller for WANs. These centralized controllers allow customers to enjoy the benefits of SDN without the commitment of a full SDN deployment. The Uni-Controller technology will be compatible with the three controllers and will also provide interfaces to OpenFlow and IRS architectures.
The third innovation is the Hybrid SDN architecture. This architecture allows physical devices to be managed by the SDN controller while maintaining traditional routing mechanisms and effectively eradicating the reliability and smooth evolution problems found with SDN controller deployments.
Huawei Agile Network is engineered to address the core necessities of network development and to eliminate the major network infrastructure problems facing traditional networks. The transition from reactive mode (adapting services to networks) to proactive mode (adapting networks to services) forms the foundation for building service-friendly networks. Huawei's ultimate goal is to help enterprise customers deploy the most modern, easy-to-use, and efficient communication technologies available for their networks.