Cisco's first storage switch raises the bar

Cisco has entered the storage  market with a bang, introducing a feature-rich, director-class switch that in our tests delivered some of the best performance metrics we've ever recorded. In an exclusive Network World product test, the 112-port Multilayer DataCenter Switch (MDS) 9509 demonstrated wire-speed throughput for small and large frames at 2G bit/sec rates.

The MDS 9509 also sports some noteworthy features, including support for virtual storage-area networks (VSAN), a Cisco innovation that contributes to high availability and scalability.

This combination earned the MDS 9509 our World Class award.

We tested Version 1.0(1) in mid-December when Cisco released gold code. The product will not be widely available until IBM starts reselling it as part of a deal the two giants announced this week. (See story)

Management was not only excellent, but also is supported on the MDS 9509 at no extra charge. Cisco says per-port pricing will cost about $2,000.

The MDS 9509 is a modular, multislot chassis with two slots for the switch fabric and seven switching module slots that can accommodate MDS series blades. It is a 2G bit/sec Fibre Channel system, and that is the rate at which we tested it. But like other Fibre Channel switches, it can autonegotiate down to 1G bit/sec.

While multiple protocols, including Fibre Channel over IP, Internet over Fibre Channel Protocol and iSCSI, are supported on the MDS 9509, FICON  and ESCON are not. Without FICON - which is essentially ESCON over Fibre Channel - the MDS 9509 won't be able to network with IBM mainframes. Cisco says FICON support is planned, but did not provide a time frame.

Performance details

•  In a 30-second test using large, 2,148-byte packet frames, bidirectional per-port throughput was 210M byte/sec on all ports, which represents 100% line rate.

•  With 60-byte frames, under a 100% delivered load on all 112 ports, raw throughput was 150M byte/sec per port, which is 98.7% of the bidirectional theoretical line rate - the highest we've ever observed on director-class switches in a multiport test using small frames.

In these two tests, traffic was delivered on one port and came out on another port on the same blade. In our next tests, traffic went into one port and came out on another port on a different blade. This forces the MDS 9509 to switch traffic between ASICs through the switch, which let us check for blocking within the switch's fabric. The MDS 9509 proved to be totally nonblocking, even in our full-mesh tests.

In a full-mesh test using large 2,148-byte frames, we had 100% theoretical maximum throughput, which we have observed on director-class switches from McData and Brocade - but only when running at 1G bit/sec (see review). The tests on the Cisco box were conducted at 2G bit/sec.

The MDS 9509 had a maximum latency of 219 microsec when tested with large frames. We've seen director-class switch latencies ranging from 174 microsec to more than 600 microsec.