DX Unified Infrastructure Management

  • 1.  Card is/not in HA mode

    Posted Aug 21, 2013 02:11 PM

    Card is in HA mode
    You can only create Hardware Filters. Hardware Filters do not affect data throughput because the packets are filtered out within the 10Gb card, before they are ever sent down to the driver.

    Card is in Non HA mode
    With Software Filters, the CPU is used to process all of the packets before allowing them to enter into the Packet Capture memory buffer. Depending on the complexity of the filter(s), the amount of time required by the CPU to process the packet can be high. This increases CPU utilization. When CPU utilization goes up, it takes more time for the GigaStor to index data at higher rates of speed. This is because the CPU is being dominated by the filtering processes. So yes, creating simple filters will cut back on CPU processing time. Creating pattern based filters which require that packets be searched within a range of bytes for a data sequence would take significantly more time to process than an IP Address filter.

    Software based filters do not affect data throughput but affect systems CPU. So anything that uses the CPU, like the 10Gb driver, would be slowed down by applying a software based filter. So these filters indirectly affect data throughput from the driver into memory. This is because the driver is processing packets and creating the proprietary Network Instruments packet headers before sending the packets to the appropriate memory buffers. All of this processing and header creation occurs within the CPU.

    Kemal Ajan