Nortel recently commissioned the Tolly Group to size up the Layer 2 switching performance and resiliency of its Ethernet Routing Switch 5000 series of stackable switches, and to compare the performance to that of Cisco\u2019s Catalyst 3750G and HP\u2019s ProCurve 3400cl.As usual with Tolly\u2019s tests, keep in mind that a vendor has paid for it (in this case, Nortel), but the testing organization is very up-front with that.In this test the Tolly Group says it measured the frame forwarding rate, latency and jitter characteristics of an eight-switch stack of Nortel switches against similarly configured stacks of the Cisco and HP switches. The tested switches included 24-port and 48-port Gigabit Ethernet models.Nortel\u2019s switch stack reached frame forwarding rates of more than 300 million frames per second for 64-byte frames, while HP\u2019s stack reached 171 million and Cisco\u2019s stack reached 38 million. Frame loss for the Nortel stack was zero, while Cisco\u2019s stack reached 87% for 64-byte frames. HP\u2019s frame loss ranged from 43% to 45%, depending on the size of the frames.Vendors appear to be piling up on Cisco\u2019s Catalyst 3750G. You may recall that last month I relayed results of Tolly\u2019s tests (sponsored by 3Com, of course) pitting 3Com\u2019s Switch 5500G-EI against it.The new report notes that Cisco did not respond to an invitation to review the test results. It also says HP did not contest the results - but did point out that its preferred approach to stacking switches is different from what Tolly tested.The full, free report is available online.