Single or dual [shown here] supervisors go in the center slots. Positions 1,2,5 and 6 hold line cards. There are two line card varients -- SFP+ and QSFP as shown here. For every QSFP port set in 100 Gb/s mode, a port is disabled. With 24 ports per card and half disabled, the switch can support 48 100-Gb/s ports across four line cards. With that restriction, Cisco says the switch is line rate. There is an asterik on that with a minimum packet size. At 40 Gb/s, all portts can be used -- so 96 ports. The switch uses Cisco's UADP3.0 switch ASIC.

This switch has all the smarts on the supervisor card and the line cards are just a collection of jacks. There is no buffering or queuing on the line cards. That Cisco calls this Supervisor 1 may portend a more powerful future supervisor that can hold more TCAM or activate more simultaneous 100 G ports. No product announcements here.

Each ASIC has 36 MB packet buffer, not all of which is available for burst absorption. Estimate that after fixed port and backplane allocations are accounted, 23 MB is the size of the dynamically assignable pool. Packet memory on each ASIC is local and therefore not available for sharing with ports on other ASICs.