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How to calculate the PFC frame rate on Spirent TestCenter?


 Here is an B2B example:

  1. port1 create a stream with VLAN priority 3, set the port load to 100%;
  2. Enable "Priority 3" in the "1/10Gig Advanced" tab of port1
  3. port2 create a PFC stream, set the "Class enable vector" and timer;

Start traffic on port1, the Tx L1 rate should be 100%, if you want to control it to 50%, how to set the fame rate on port2?

  1. We set the timer to be 65535, so traffic stop time of one pause frame should be 65535*(512bit/10,000,000,000bit/s) = 3.355ms
  2. "Tx rate down to 50%" means the stop time is 0.5s during 1s, so the PFC frame number send in 1 second should be 0.5s/3.355ms = 500/3.355 = 150;
  3. set the frame rate of port2 to 150, the L1 Tx rate of port1 should be near 50%.

Attached the B2B tcc in V4.36. 


Product : Chassis