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Spirent TestCenter: How many bytes of headers can be inserted into a frame?

  • Spirent TestCenter v4.97
    • DX-10G-S32
    • DX2-100GO-P4
    • FX2-100GO-P4
    • MX2-100GO-P4
    • PX3-100GQ-T12
    • DX3-400G
    • PX3-400G
    • 400G Appliance
  • Max frame template sizes (aka how many bytes of headers you can insert).
  • 400G - 128 bytes or 192 bytes depends upon version and model
    • message will appear when adding to many bytes to the custom header
  • 200G - 128 bytes or 192 bytes depends upon version and model
  • 100G - 480 bytes
  • 50G - 480 bytes
  • When you hit this limitation you will see an error similar to:
    • Error encountered while sending message to configure stream block(s). Stream block (Ipv6:port2:1): Invalid input parameters: Can not allow frame content size more than 128 bytes. 
      Spirent: 05:00:34.468 ERROR - Error encountered while sending message to bind load profile(s) to stream block(s). Invalid input parameters: Cannot find stream block id 100569 in database.
  • On the 400G there may be a Custom Fill Pattern in which you could try as a way to extend what is needed in the payload/headers to get around the limitation.
  • The HYPERMETRICS DX 32-PORT 10 GBE TEST MODULE also does NOT support greater that 480 byte HEADER size and there are no plans to implement in the future.
  • The frame length of the packet is different from the frame content size from the perspective the HW.
    • Frame content size is the size of defined headers in the stream block configuration (e.g., ethernet, IPv4, custom header).
    • It doesn’t include HW generated background fill.
  • You can send a packet that is a frame length of 8100 bytes but the frame content is only Ethernet and a custom header with only two bytes of data.
    • The Ethernet header and the two bytes of custom header data is well within the 480 byte frame content size limit.
  • As a workaround it is suggested to use background pattern, as data is all FFFFs however this does not meet all config requirements.
    • If work around doesn't meet the configuration requirement, please use a different module.  The DX module simply cannot be used for these situations.

Product : Spirent TestCenter,PGA,DX