I was recently shown the HP 3800 switches, and their stacking technology. The 3800-series are gigabit switches with 24 and 48 port models with PoE and 10Gb/SFP uplinks.
What is unique about these switches, is that not only do they support up to 5 fully meshed switches, but HP claims to have larger thoroughput with each link over Juniper and Cisco's line. For example, Cisco claims to have 16Gbps bi-directionally through each port, giving total bandwidth up to 32Gbps across the stack. Juniper claims to have 32Gbps per port, with a total bandwidth of 64Gbps across the virtual chassis. HP, however, with each switch having 4 dedicated stack ports, claims to have 84Gbps across each stack port, bi-directionally, with a total of 336Gbps across the stack cables.
Need more than 5 switches in a cluster? HP says, no problem. The 3800-series can support up to 10-switches in a ring-topology. When utilizing the ring-topology, you are using 2 of the 4 ports, decreasing your stack bandwidth to 168Gbps, but adding more switch ports. At this time, HP does not support hybrid ring/mesh configurations.
On the back of each switch can be a 4-port stacking module, shown below:
Each cable is a specialized stacking cable, with a maximum length of 3 meters. The 3 meter limitation is a technical limitation in order to keep the high-end speeds that HP claims to have. Shown is the stacking cables when using a fully-meshed architecture.
HP has shown that the 3800 switches average a 3-5 micro-second forwarding latency across all size frames except jumbo frames. For the jumbo frame sizes, they show the 3800 to still be 3-6 micro-seconds faster than Cisco and Juniper.
The 3800 switches are available and shipping now worldwide with a starting base list price of $4969.00. You can find more information from HP's product page at http://h17007.www1.hp.com/us/en/products/switches/HP_E3800_Switch_Series/index.aspx