Cisco MDS 9124 Fibre Channel Switch

Cisco has been spending a lot of time now with a very keen focus on the SMB networking infrastructure and communications markets with it delivering some very affordable and sophisticated products.

Good examples are its Catalyst Express 500, which provides a slick switching solution with ease of use high on the agenda whilst the ISR 2821 offers a veritable feast of communications capabilities. Cisco now turns its eye to the lucrative fibre channel (FC) SAN switching arena and in this exclusive review we take a closer look at its latest MDS 9124 fabric switch.

The FC switching market is an unusual one as the only key vendors in it are Cisco and Brocade and, to a lesser extent, QLogic. Brocade also acquired McDATA last year in a response to Cisco's increasing dominance. Not bad going considering Cisco only entered this market in 2003 because of one of its infamous "spin-ins" with start-up Andiamo. Traditionally, it has focused on the core switching markets but the MDS 9124 is aimed not only at enterprises looking for an edge switch but also at smaller businesses embarking on their first SAN but with very strict budgets.

The 9124 offers 24 SFP ports which support 4Gbps, 2Gbps and 1Gbps transceivers so it'll have no problems mixing the latest high speed arrays with your legacy kit. A key selling point is that you can license the ports in increments of eight at a time allowing you to expand only when demand dictates. True, Brocade has been doing this for years but Cisco differs in its approach as you can choose which ports you want activated. This pays dividends if a licensed port packs up as you can deactivate it and use the license to bring up another port. Other benefits of the 9124 are that full fabric and device management tools are included in the price whereas tools such as Brocade's Fabric Manager and Watch utilities are optional extras.

Cisco's VSAN (virtual SAN) technology is not only supported by the 9124 but it'll manage up to 16 straight from the box. VSANs provide extra flexibility as businesses can install cabling once and then dynamically configure the SAN and its connections. These come into their own where various applications such as email and backup need to be separated out into their own SAN. Achieving this with some competing products would require separate physical switches but VSANs allows you to separate the ports on the 9124 into independent groups.

You also get up to 16 buffer credits per port thrown in as standard as well. To maximise performance, buffer credits allows extra frames to be placed on the wire even when the switch is still awaiting acknowledgements.

This brings benefits in increased distances over FC so using buffer credits over a 2Gbps link means the port can support links of up to 60kms. There's much more as Cisco claims its QoS features make it unique. Using DiffServ it allocates gold, silver and bronze values to specific links allowing you to optimise performance. A typical scenario would be links to off-site storage where the replication link would be tagged as gold whilst the backup link tagged as silver.

As with its other SMB products, Cisco has worked hard on ensuring the initial installation process is as painless as possible. First contact with the 9124 is, unfortunately, via a CLI session although this is mercifully brief as you just need to secure administrative access, set up an IP address for out-of-band management and configure basic SNMP parameters. You can also set up in-band management using IP over FC for the default VSAN as well if you wish.

Your next task is to point a browser at the switch but this is only to access the download page for the Fabric and Device Manager utilities. Cisco doesn't support browser management as it feels that accessing the switch over SNMPv3 provides greater security. A quick configuration wizard gets you up and running and this provides easy access for creating zones, adding ports and assigning them to VSANs. The wizard offers up a grid showing all available ports so all you need do is tick their boxes and decide which VSANs they belong to. Note that by default all FC ports are disabled but they can be individually enabled from this grid as well.

The Fabric Manager is easy enough to use and opens with a menu bar to the left and a fabric map view opposite. The switch appears in the map with associated connections and a handy feature is the ability to export the fabric map as a graphic and save off switch details, ISLs (inter-switch links) and host tables to a CSV file allowing you to document your own SAN.

Administrative access is controlled using roles and a wizard in the Fabric Manager aids with user creation here as well. Users can have Config, Show and Exec permissions and have access restricted to specific VSANs. You can limit users to a management IP address, allow access only to certain CLI commands and even apply these to a specific interface and VSAN. QoS must be set up from the Fabric Manager as this is applied end to end and not zone to zone. Again, you get wizard assistance, which guides you through selecting VSANs and included zones and assigning low, medium or high priorities. Activating more ports is easy enough as you simply enter your new license details in the Device Manager and decide which ports should acquire a license.

FC SANs have traditionally been beyond the means of SMBs thanks to their high prices and complexity. Cisco's new MDS 9124 breaks the mould as it delivers a wealth of features at a sensible price, streamlines installation and configuration and offers a flexible licensing scheme that allows small businesses not only to pay for the ports they need but also choose which ones they want to use.

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