As an effective marketing technique, legend has it that Cisco introduced the 2955 at a trade show by connecting all 12 ports to responding devices and then placing the switch into a paint shaker. After rattling the box around there for a while, the Cisco representative was said to have switched off the shaker without losing a single connection.
Unfortunately, though we scoured the island of Oahu (I did my testing at the University of Hawaii’s Advanced Network Computing Lab), I was unable to find anyone who would lend a bunch of caffeinated geeks a paint shaker long enough to verify this claim. All I was able to find was a Spirent Smartbits 600. I made good use of this device, however, by first blasting true wire-speed traffic at 100-percent utilization to all 12 ports in a variety of packet sizes from 64-byte size to as many as 1518 bytes. And although I reached the 2955T-12’s full capacity of 4.8Mpps (at the nasty 64-byte size), the swtich didn’t drop anything.
Cisco was also highly concerned with latency for these switches. That’s because in the company's intended environment, namely factory floor automation, running large amounts of highly complex equipment on an exact schedule requires near-zero latency numbers. Again the 2955 didn’t disappoint even in a full-mesh configuration, dividing traffic equally from each single port to all the other ports. Here, the 2955 showed numbers as low as 3 microseconds depending on packet size.