1. Configuration Guide
  2. System Configuration
  3. HTTP Connection Management

HTTP Connection Management

By default, the SBC limits system impact caused by HTTP client behavior using the httpclient-max-total-conn and httpclient-max-cpu-load parameters in the system-config. These parameters allow you to change the number of TCP connections and the amount of CPU resources consumed by traffic between the SBC and all types of HTTP servers.

Use the following system-config parameters to adjust or disable management of the number of active HTTP clients by the SBC:

  • httpclient-max-total-conn—Specifies the maximum number of TCP connections that the http-client allows open simultaneously.

    When this traffic exceeds this value, the SBC and the http-client begin to discard new http/https requests. When used TCP connections falls below this value, the SBC resumes accepting HTTP client TCP connections.

    Valid Values:

    • 0—Disables the function
    • Range—0 - 2147483647
    • Default—500

    You cannot configurehttp-client in real time. You must reboot the system whenever you make a change.

  • httpclient-max-cpu-load—Specifies the maximum percentage of CPU consumed by HTTP traffic during STIR/SHAKEN operations.

    When CPU resource utilization exceeds this value, the SBC, the http-client begins to discard new http/https requests. When CPU utilization falls below this value, the SBC resumes accepting this traffic.

    Valid Values:

    • Range—30% - 90%
    • Default—70%

    You can configure httpclient-max-cpu-load in real time.

  • httpclient-cache-size-multiplier—Specifies the multiplier used to calculate the size of the HTTP client connection cache.

    The system maintains an HTTP connection cache pool. This is a collection of previously used connections that the system keeps alive, instead of closing after use, so that subsequent transfers targeting the same host name can use them instead of creating a new connection. The size of the HTTP connection cache is based on the number of these live connections.

    The system calculates this cache size using the formula:

    client connection cache = (number of pending transactions * httpclient-cache-size-multiplier)

    Valid Values:

    • Default: 16
    • Values: 4 - 50

    You cannot configure the http-client in real time. You must reboot the system whenever you make a change.

You use the Http/s calls Dropped field in the show sipd errors command to monitor dropped HTTP traffic.