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Spirent TestCenter: Do frames with FCS, IP checksum or UDP checksum errors increase the frame drop counters in Spirent TestCenter?

Answer
  • If you do receive the errored frames at a Spirent TestCenter (STC) port then it will receive and process the frames.  Unlike your NIC on your PC which will drop an errored frame at the “phy.”
  • STC also will not only count the frames at the port level, but also, as long as the signature is not corrupted, track them at the stream level too. This means:
    • all sequencing and latency statistics will be tracked as normal
    • a frame with a CRC (i.e., ethernet FCS) or IPv4 or UDP checksum error will not be considered as dropped
  • Note:
    • that if such traffic is being received by a DUT then, in particular, if the frame has an FCS error, the DUT will report this on its rx counters and will drop it. 
    • A DUT typically does not have counters indicating that it sent errored frames.  That is, as far as it knows, it sends the frames correctly so if STC is reporting this then you should check the transceivers or interconnects (i.e., copper or fiber between the DUT and STC ports).

 

Product : Spirent TestCenter,PGA