Dell this week extended its data centre networking portfolio with a new top-of-rack switch and plans to extend OpenFlow support for software-defined networking across its product line.

The new switch is the Dell S4820T, which is designed to help users migrate from Gigabit Ethernet server-to-switch connectivity to 10G Ethernet. It also features 40G Ethernet uplinks for 10G aggregation and connectivity to higher-end aggregation and core switches.

The S4820T sports 48 1/10G 10GBase-T copper ports and four 40G uplinks that can also be configured as 10G uplinks. The switch is being lab tested by 10GBase-T network interface card and converged network adapter vendors Broadcom, Emulex, Intel and QLogic for, in some cases, its ability to interoperate using the Data Center Bridging standard for converged LAN/SAN carriage.

The S4820T, which is available now at around $35,000, also supports VMware and Citrix hypervisors, Dell says. It will also eventually support OpenFlow for software-defined networking.

Dell said OpenFlow 1.0 is available now in its FTOS 9.1 operating system software for its Z9000 and S4810 data center switches. The software allows those Dell switches to be managed by OpenFlow-compliant controllers, like those from partner Big Switch Networks, and by multiple controllers at the same time.

Dell supports a hybrid approach to SDNs, in which the OpenFlow controller will interact with the control plane of Dell switches to enable customers to simultaneously deploy traditional Layer 2/3 forwarding with OpenFlow. This allows network operators to integrate OpenFlow into existing networks and segregate SDN for specific flows while the remaining traffic is handled as before - a technique referred to as network slicing.

The hybrid approach is similar to that endorsed by Brocade.

More Dell switches will attain OpenFlow capabilities as FTOS 9.1 and later versions are added to those switches. Dell officials say FTOS will jump right to OpenFlow 1.3, the most recent version of the SDN protocol, from 1.0.

Meanwhile, Dell says its MXL/IOA blade switching system, which was introduced at Interop Spring 2012, is one of the fastest growing product lines in its portfolio. Dell says it has shipped over 3,000 units to more than 700 customers in about two quarters. Customers are using the system for east/west traffic optimisation with direct 40G connectivity from a Dell PowerEdge 1000e blade server rack to the core fabric, Dell officials say.