IBM Software Defined Networking: Two Approaches to Network Virtualization and Centralized Network Management

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1 Research Report IBM Software Defined Networking: Two Approaches to Network Virtualization Executive Summary Software defined is a common buzzword today there is a lot of discussion around software defined networks, software defined storage, and more broadly software defined environments. The key concept in this software defined discussion is programmability. Instead of relying on vendors to provide all device programming, software- defined environments make it possible for information technology (IT) buyers to program their systems, storage and network devices to meet their specific enterprise computing requirements. As a consequence, software defined environments make it possible for IT buyers to structure heterogeneous computing environments that serve to accelerate time to business value and avoid vendor lock-in. There are several major benefits to being software defined: (1) Heterogeneous hardware support By creating a layer of abstraction between software and the underlying hardware, the software operates independently of hardware, and customers are free to mix servers, storage devices and networking hardware, including switches minimizing cost and getting a better return on their existing investments. (2) Pooling of infrastructure resources Pooling of virtualized infrastructure resources allows storage, servers and networks to be provisioned on-demand, assigning resources as needed and returning them to the pool when finished, so they can be made available to other workloads, helping achieve better asset utilization. (3) On demand resource provisioning Users can easily provision resources through a user-oriented service catalog increasing speed of deployment, improving end user experiences and freeing administrative resources for more complex activities. (4) Centralized management and control Centralized management of infrastructure elements eases administration and improves productivity. Rather than setting up hardware devices manually one-at-a-time, configuration and management of hardware can be done through software, reducing operating expenses as well as errors associated with manual set-up. In this report, we focus on software defined networking (SDN). With advances in both server and storage virtualization over the past several years, networking has struggled to keep pace. Networks have become a major bottleneck, hindering data center scalability and performance, as well as slowing the adoption of large-scale hybrid clouds. To illustrate how SDN works with cloud architecture, we use IBM as an example of a vendor that has developed a solid SDN strategy and a comprehensive set of products. We examine IBM s

2 SDN product offerings in the context of the SDN market, as well as in relation to IBM s overall cloud and software defined strategy. SDN Background Addressing the demands of today s workloads including big data analytics, mobile, and social business applications requires virtualization across the enterprise infrastructure. High performance, massively scalable virtualized servers as well as high speed, high capacity storage technologies need a highly virtualized networking infrastructure to be able to deliver on the benefits of virtualized storage and servers. Networks must be capable of delivering the same type of speed and agility as their other infrastructure counterparts. Legacy networking solutions that employ protocols such as spanning tree were not designed for today s environment of complex mobile, dynamic infrastructure and changing workloads. Vendors have adopted many different protocols as networks have evolved. As a result, interoperability is limited and vendor lock-in is a frequent issue. Network switches, in many cases, must be configured manually switch-by-switch which impacts efficiency and productivity as networks scale. This inefficiency results in network device underutilization which adds to overall infrastructure cost. To enable virtual machine (VM) mobility with current network architectures, IP and MAC addresses must be retained, limiting growth and scalability in virtualized cloud infrastructure and requiring manual setup for provisioning multiple tenants. Network virtualization creates a more agile network that is capable of supporting both server and storage virtualization and managing the increase in the number of VMs deployed. This results in an IT infrastructure that can respond to business needs more quickly. Network virtualization also allows network resources to be provisioned at a much faster rate, reducing time to market for new business applications. Network virtualization is an important part of SDN. SDN enables network virtualization as well as centralized configuration and management of network resources improving administrator efficiency, providing better reliability, enhanced security and greater performance and scalability. SDN: Two Approaches Building SDN networks can be approached in different ways: 1. For clients who want better system virtualization and more networking control without making an investment in new network switches and controllers, virtual network overlay technologies are the best bet since they can be implemented on top of an existing physical infrastructure. 2. Businesses building networks and next-generation data centers from the ground up should consider building networks with devices and appliances supporting OpenFlow, an evolving SDN standard. Option 1: Virtual Overlay Networks Making Use of Existing Infrastructure In a virtual overlay network, the virtual network is decoupled from the physical network (by means of a network hypervisor), essentially enabling a virtual network to be built on top of an existing physical network. Nodes in the overlay are connected via virtual logical links each of which corresponds to a path which may traverse many physical links in October, Clabby Analytics Page 2

3 the underlying physical network. Virtual network services on a private network can be securely isolated from other tenants while still sharing the same physical network. By using an overlay network, it s possible to control network changes through software, modifying the overlay network rather than the physical network. Overlay networks also remove limitations on the number of virtual networks that can be created, enabling largescale big-data cloud environments with no changes to existing infrastructure. IP and MAC addresses can be reused across different virtual networks simplifying data center consolidation, and enabling multi-tenancy and scalability. Option 2: OpenFlow Networks For New Network Architectures and Infrastructures The open nature of OpenFlow-based SDN gives customers an option to build next generation network infrastructure based on standards, providing investment protection and interoperability using OpenFlow-enabled hardware and controllers. The OpenFlow framework uses network-aware intelligence to efficiently deliver packets within a networked environment. The control plane of most network switches in use today is proprietary. Current switch design typically does not have an open interface which would allow customers to make changes to the forwarding logic of the switch. As a result, network buyers have had to rely on their network vendors to solve problems related to virtualization, security, robustness, manageability, mobility, and more. OpenFlow seeks to provide the flexibility of programming the network making the control plane (the firmware/switching level) accessible to the user community. In an OpenFlow network, the control and data planes are decoupled, with network intelligence and control residing in a remote, centralized controller with the power to modify the behavior of all network devices. As a result, managers and administrators can control how traffic routing takes place across their networks. This enables more efficient use of the network band by the route control on a per-flow basis and the flow is programmable. In an OpenFlow network, the centralized controller can be updated rather than all the individual switches in the network. OpenFlow enables the control plane to be accessible remotely and to be modified by third-party software. With open programmatic access to the network, business applications can use network resources as needed, supporting large-scale cloud environments and dynamic applications and workloads. IBM s SDN Strategy- Embrace Open Standards IBM is a strong supporter of open standards and open source projects. Openness in networking can provide a common and consistent platform on which new applications and services can be developed. This helps vendors bring new technology to customers sooner while shortening adoption rates. IBM was an early member of the Open Networking Foundation (ONF), a user-driven organization formed to promote the adoption of SDN through standards development. The organization has about 100 members including HP, Cisco, Google, Facebook, Citrix, Oracle, Yahoo, and VMware. IBM is also a founding member and a platinum member of the OpenDaylight open source project contributing code, developers and funding. The goal of the project is to further SDN adoption and innovation through the formation of a common framework for building applications. See Figure 1 next page. October, Clabby Analytics Page 3

4 Figure 1 OpenDaylight Framework Source: IBM 2013 OpenDaylight is an open community of developers and business professionals supporting an open source controller framework and a collaborative decision-making process. IBM intends to submit an open source version of its Distributed Overlay Virtual Ethernet (DOVE) technology as its initial contribution. This is the technology used in IBM Software Defined Network for Virtual Environments (SDN VE), discussed in detail later in this document. IBM will build on the OpenDaylight platform to offer a complete SDN solution. IBM is also committed to supporting open cloud standards including OpenStack, TOSCA (Topology and Orchestration Specification for Cloud Applications) and OSLC (Open Services Lifecycle Collaboration). IBM s SDN products A Closer Look IBM sees SDN as managing complex hardware interactions with software with the goal of bringing management up a layer. SDN can be implemented in different ways depending on customer requirements. IBM embraces both an OpenFlow-based SDN solution as well as a virtual overlay solution. See Figure 2 below. Figure 2 IBM SDN Platform Source: IBM 2013 October, Clabby Analytics Page 4

5 IBM OpenFlow Network With OpenFlow, the switch control plane is decoupled from the data plane, and networks control traffic on a per-flow basis, creating multiple independent virtual networks and related policies without having to deal with the complexities of the underlying physical network and protocols. OpenFlow enables the network to be viewed as a whole for Data Center-wide physical network control and easier administration of large virtualized networks. IBM s product set includes: IBM OpenFlow-enabled switches (G8052, G8264, G8264T, G8316, EN4093/R) provide data forwarding and switching moving data from port-to-port based on the Layer 2 (MAC) flow tables residing in the switches and flow information received from the controller. IBM s OpenFlow enabled switches support both the IBM Programmable Network Controller (details below) as well as third-party OpenFlow controllers including NEC pflow, BigSwitch Floodlight and others. IBM Programmable Network Controller (PNC) maps physical and virtual traffic flows, populating flow information into the forwarding devices across any OpenFlow-based Data Center network environment. The IBM PNC provides a reliable, edge-to-edge system network fabric that can be defined for multi-tenant environments. Granular policy enforcements ensure secure isolation across multiple tenants. Administrators can use the IBM PNC to attach policies that direct overall network operations rather than making configuration updates switch-by-switch, saving management time improving efficiency and driving down management costs. See Figure 3 below. Figure 3 IBM OpenFlow solution Source: IBM 2013 IBM Software Defined Network for Virtual Environments (SDN VE) Based on DOVE (Distributed Overlay Virtual Ethernet), SDN VE is an overlay network that acts as a network hypervisor, enabling network virtualization. Multiple virtual network domains share a common physical network infrastructure, providing server-based connectivity for virtual workloads and VM mobility across Layer 2 domains. This architecture provides both network flexibility and reduces the limitation on the number of VMs per host resulting in increased scalability. SDN VE is installed on the server infrastructure and uses the existing physical network. It is easily implemented and can support any vendor s networking equipment. With IBM SDN VE, virtual networks are created giving the end-user the feel of a dedicated networking device, completely isolating traffic between virtual networks while better utilizing networking resources. October, Clabby Analytics Page 5

6 IBM s SDN VE Solution is comprised of the following (See Figure 4 below): Management Console o Provisions and configures virtual networks, Port group profile, Virtual Network (VNID) and subnets within those networks o Assigns VMs to networks and defines policies between the VNIDs SDNVE vswitch o Enhanced hypervisor switch providing connectivity to VMs o Provides connectivity to multiple virtual networks Connectivity Service o Registration, address lookup and policy lookup o Multiple nodes for redundancy and load balancing VLAN Gateway o Connects legacy virtual LAN (VLAN) VMs to an SDNVE network External Gateway o Connects the virtual network to non-sdnve networks o Connects SDNVE network domains Figure 4 -IBM SDN for Virtual Environments Source: IBM 2013 IBM SDN VE speeds application provisioning by replacing manual physical network changes with automated network provisioning. As a result, applications and network services can be deployed faster (IBM says the time required to provision a network is reduced from days to minutes). Scalability is also improved since server virtualization isn t gated by the number of network interface controllers (NICs) in the server, thereby improving server ROI. VM density is increased and VM bottlenecks are eliminated. While scaling of physical networks is constrained by the number of Layer 2 VLANs (4096 VLANs), a virtualized network domain can scale to support up to 16 thousand virtual networks today. October, Clabby Analytics Page 6

7 In addition, IBM SDN VE supports secure, scalable multi-tenancy. Automated configuration enables networks to be created from a central point without disrupting the physical infrastructure or reconfiguring hundreds of physical switches. VM movement is automated along with policies and configurations. Network services, such as firewall, load balancing, and intrusion detection can be deployed based on patterns of expertise, dramatically simplifying configuration and reducing configuration errors. Physical networks aren t able to share network addresses creating challenges for consolidation but with SDN VE virtual networks, IP addresses and MAC addresses can be reused so that networks can maintain current IP addressing schemes. IBM SDN VE supports the VMware environment today, but IBM plans to add support for additional hypervisors such as KVM and Hyper -V. IBM SDN VE works with any x86 server, including those in IBM s PureSystems and NeXtScale solutions IBM Customer Wins in SDN Tervela, a provider of a market-leading distributed data fabric that does $4.2 Trillion in daily trading volume uses IBM s OpenFlow enabled switches with an NEC controller OpenFlow promises Tervela s customers a competitive edge by ensuring that the network adapts dynamically to business needs by, for example, automatically segregating network traffic based on realtime statistics. The IBM/NEC solution enables our customers to use OpenFlow s programmable intelligence using high-performance network components that also simplifies the complexities of managing mission-critical networks. Director of Software Engineering, Michael Matatia. Source: IBM Selerity, a real-time financial information and media company, also uses an IBM OpenFlow-based solution. OpenFlow gives us the flexibility of an application with the performance of a switch. The combination of NEC OpenFlow controller and IBM RackSwitch can distribute data across our global low-latency network in an innovative way that can be as much as 1,000 times faster than a conventional server-based application. Chief Technology Officer Andrew Brook. Source: IBM The University of Groningen, one of the largest research universities in Europe, selected IBM to design an SDN platform for research based on the collection and management of large amounts of data. With this big data platform, the University of Groningen has a solution that will support their needs well into the future as they continue to conduct ground-breaking scientific research. Summary Observations In this Research Report, Clabby Analytics has defined the term software defined and why it is important. We used one vendor (IBM) to show how IT buyers might structure their own software defined environments. More specifically, we examined IBM s SDN solutions and we showed two complementary approaches to building a software defined network: 1) an overlay solution based on DOVE, IBM SDN VE enables customers to use existing server and network infrastructure, as well as 2) an OpenFlow-based solution October, Clabby Analytics Page 7

8 including an OpenFlow controller (the Programmable Network Controller) and OpenFlowenabled switches. IT buyers who take the overlay approach will find that IBM s SDN VE enables users to adopt SDN on a small scale or for a small application without making a huge investment any existing networking equipment can be used and the server requirements are minimal. The overlay technology automates the process of creating or sunsetting virtual networks in a matter of seconds or minutes rather than days, plus helps improve VM mobility in virtual environments. In addition multiple virtual switches can be configured through software rather than manually setting up each one individually, saving time and improving productivity, another key benefit of SDN. Each approach to SDN (overlay or OpenFlow) has its benefits. The two approaches are complementary and can be used together. Over time, Clabby Analytics believes IBM may offer a converged controller that will make it easier and more-cost-effective to connect and operate IBM SDN VE and OpenFlow-based networks. With IBM s strengths in networking, storage and servers as well in manageability and cloud architecture IBM is poised to be a leader in building customer s software defined environments and software defined data centers. IT buyers who are looking for a cohesive software-defined strategy; who are interested in eliminating vendor lock-in; who are interested in improving system/storage/network efficiency through on-demand provisioning; and who are interested in improving overall information system management and control should closely examine IBM s approach to building software defined environments. Clabby Analytics Telephone: 001 (207) Clabby Analytics All rights reserved October, 2013 Clabby Analytics is an independent technology research and analysis organization that specializes in information infrastructure and business process integration/management. Other research and analysis conducted by Clabby Analytics can be found at: