VIAVI TestCenter: What are some of the capture limitations with the DX/DX2/DX3 and PX3 modules/appliances?

VIAVI TestCenter: What are some of the capture limitations with the DX/DX2/DX3 and PX3 modules/appliances?

• Because of the higher port densities of these modules, port capture is performed in software using VIAVI's soft FPGA logic.  This causes port captures to have the following limitations: • The port cannot capture traffic at higher line rates when using smaller frame sizes.  i.e. Some 64-byte frames will be dropped at 10% load, whereas 256-byte frames will not be dropped at the same load.   • If the user encounters dropped frames during port captures, it's recommended that the user increase the frame size or reduce the traffic load. • If the frame has a Signature field, then it will capture only 144 bytes of the frame.  • It will capture the 1st 128 bytes, thereby truncating the rest of the payload, except for the first 16 bytes of the signature field at the end of the frame. • if the frame does not have a Signature field, the entire frame will be captured.