Juniper’s SDN strategy isn’t built on OpenFlow, but rather uses a uses a mix of its network management software (Junos Space) and the Contrail network overlay controller that it acquired in late 2012 and open sourced last fall. Its overlay approach is similar to VMware’s NSX and other virtual networks that are built using tunneling protocols over TCP/IP.
Like Arista, Juniper touts the programmability of its hardware, specifically the MX edge routers and EX and QFX series switches, with open APIs providing the means to automate network management, configuration, and control. By open sourcing Contrail, it appears Juniper would rather focus on providing application-layer network services and orchestration for its legacy switching fabrics than centralized physical layer flow control.
Dell is taking a much less aggressive approach to SDN than its competitors. Dell’s SDN strategy rests on its Active Fabric and associated network management and orchestration software that' is designed to automate many of the manual tasks required to deploy and configure a Layer 2/Layer 3 fabric, including support for several network topologies. Dell’s SDN features fall into three categories: physical layer SDN using an OpenFlow controller and compatible switches; virtual network overlays supporting both NVGRE (Microsoft hypervisors) and VXLAN (VMware and Citrix); and a set of automation APIs focused on popular scripting languages, including TCL, Perl, and Python.
Further evidence of Dell’s evolutionary approach is support for hybrid switch fabrics, which it says support OpenFlow in a hybrid mode, which means that the switches can be leveraged both for SDN and regular Layer 2 and Layer 3 forwarding.
[Read what some experts had to say at Interop about the need for network engineers to have programming skills in order to work in a future of software-defined networks in "SDN: Programming Skills Needed -- Or Not?]
Dell is adding OpenFlow support to more switches, including campus access layer products like the top-of-rack N-Series. Although Dell has previously partnered with Big Switch to provide the OpenFlow controller, it changed course last fall by developing its own controller. Its controller “is made to stitch all the datacenter infrastructure products together, not just networking,” saidys Arpit Joshipura, VP of product management for Dell Networking. “So it’s not SDN. It’s really SDE, or a software-defined enterprise controller.”
Dell also is working with the Open Networking Foundation (OpenFlow) and OpenDaylight to develop northbound API standards with the goal of merging OpenFlow and interoperable northbound APIs into a single infrastructure controller, Joshipura saidys.
Brocade, like Dell, is hedging its SDN bets by participating in all the major software-defined working groups, including ONF, OpenDaylight, and OpenStack (cloud orchestration). It’s also gradually adding OpenFlow support across the product line. Brocade espouses an evolutionary approach by implementing a hybrid port mode on its MLX Series core routing chassis. This allows simultaneously running L2/L3 MPLS forwarding along with OpenFlow on existing network fabrics, in which OpenFlow provides programmatic control of specific flows while all other traffic on the same port is routed as usual.
Besides the MLX, Brocade supports OpenFlow v1.0 on its entire NetIron line of routers and switches, including the XMR, CER, and CES 2000 series. Brocade also offers a set of virtual network appliances, including the ADX application delivery controller and Vyatta virtual router and firewall, which, that can be deployed on any of the popular hypervisors and virtual network overlays.
Alcatel-Lucent/Nuage builds its SDN strategy on a combination of a flat, redundant datacenter network fabric called the Application Fluent Network and a virtual network overlay acquired from Nuage Networks. The company is gradually incorporating OpenFlow (version 1.3 in this case) into its fabric switches, specifically the OmniSwitch 6900 (ToR) and 10K (core) lines, while using its own proprietary API as a northbound application and automation interface.
Alcatel sees a few promising enterprise SDN use cases enterprise SDN use cases. One is optimizing wireless traffic by dynamically routing demanding flows, such as real-time video streams, between Wi-Fi controllers to eliminate bottlenecks. Another is enhancing application security by having a network controller automatically set security policies for new virtual workflows, while also detecting and blocking malicious traffic at the edge.
Nuage is one of the innovative startups that, like Nicira (since acquired by VMware), Midokura, and Embrane, builds virtual network controllers and application services on top of existing Layer 3 networks using tunneling protocols and hypervisor vSwitches. Thus, pairing Nuage with Alcatel’s programmable fabric means the company has top-to-bottom, Layer 2 through Layer 7, SDN coverage.