(Optional) Internet Content Adaptation Protocol Capture

Internet Content Adaptation Protocol (ICAP) is a service protocol that encapsulates HTTP messages into ICAP Messages and forwards them to an ICAP server for processing.

NwDecoder supports capturing ICAP Messages and converting the HTTP requests and responses into packets. The capture device is named icap, ICAP Server, and can be used simultaneously with other capture devices (i.e., packet capture).

ICAP Capture Options

The capture options are specified on Decoder in the configuration node /decoder/config/capture.params

You must restart the capture before any changes take effect.

  • reqmod=<bool> - By default, the Decoder will process both REQMOD and RESPMOD messages. Since the RESPMOD contains both the request and response, it may be advantageous for Decoder to ignore REQMOD messages and only process RESPMOD. If you set the reqmod=false, the Decoder will generate a request packet and response packets from a single RESPMOD message. The default behavior is equivalent to reqmod=true

  • client_ip=<string> - You can configure some ICAP Clients to include the originating IP address in the ICAP headers. The name of the header with this information can vary, so you can use this setting to specify the name of the client IP header. For example, client_ip=X-Client-IP would configure the Decoder to extract the IP from the X-Client-IP header. Ignoring this setting will disable searching for the header.