Napatech Network Adapters are designed with high performance in mind from the start, especially in a situation where the host application needs to be in-line on a heavily loaded network link.
Features supporting transmit are:
- Host-based Transmit: Host-based transmit allows frames to be generated by the host and transmitted at line speed on the network.
- Host-based Retransmit: Traffic is first captured and transferred to the host and then forwarded out again on the adapter for resending. Host-based retransmit allows frames to be modified by the user application before they are retransmitted to the network.
- Local Retransmit: Network traffic is redirected on the adapter itself without being transferred to the host.
The host-based transmit and retransmit functionality can be accelerated or controlled via the Napatech transmit features:
- MAC CRC Recalculation: Can be performed by the adapter if a captured frame has been modified, or a new frame has been generated to be transmitted. Frames can also be retransmitted without the adapter recalculating the MAC CRC to enable the appliance to be transparent on the network. For frames being generated by the host, the MAC CRC can also be transmitted unmodified by the adapter to allow transmission of frames with bad MAC CRC.
Inter-frame Gap (IFG) Configuration: Enables precise IFG control. The IFG (the time delay between frames on an Ethernet network) can be controlled individually for each transmitted frame (with a typical precision below 40 us).