At this current moment we use 2 PowerConnect 5424 switches for our iSCSI backend network. The PowerConnect 5424 has 24 10/100/1000 BASE-T auto-sensing gigabit Ethernet switching ports and 4 SFP combo ports for fibre connectivity.
The PowerConnect series of switches have many good features some which are irrelevant to what I am talking about so I will leave this out and comment on the features which are important in relation to iSCSI backend networks. Notice I say backend, if this were not a backend network I may be interested in some of the other features such as multiple VLAN capability and iSCSI optimization and QOS. But as this is a backend network I will not require the use of multiple VLANS or iSCSI optimization as I don't see the need to optimise iSCSI on purely iSCSI network.