HTTP_FLOWRATE_INFO structure (http.h)

The transfer rate of a response

Syntax

typedef struct _HTTP_FLOWRATE_INFO {
  HTTP_PROPERTY_FLAGS Flags;
  ULONG               MaxBandwidth;
  ULONG               MaxPeakBandwidth;
  ULONG               BurstSize;
} HTTP_FLOWRATE_INFO, *PHTTP_FLOWRATE_INFO;

Members

Flags

An HTTP_PROPERTY_FLAGS structure specifying whether the property is present.

MaxBandwidth

The maximum bandwidth represented in bytes/second. This is the maximum bandwidth for the response after the burst content, whose size is specified in BurstSize, has been sent.

MaxPeakBandwidth

The peak bandwidth represented in bytes/second. This is the maximum bandwidth at which the burst is delivered.

BurstSize

The size of the content, in bytes, to be delivered at MaxPeakBandwidth. Once this content has been delivered, the response is throttled at MaxBandwidth. If the HTTP Server application sends responses at a rate slower than MaxBandwidth, the response is subject to burst again at MaxPeakBandwidth to maximize bandwidth utilization.

Remarks

This structure allows an HTTP Server application to maximize the network bandwidth use by throttling down the transfer rate of an HTTP response. This is especially useful in serving media content where the initial burst of the content is served at a higher transfer rate and then throttled. This allows content from a larger number of media to be served concurrently.

The transfer rate is allowed to exceed MaxBandwidth in two cases:

• If the connection slows and the transfer rate falls below MaxBandwidth, the application can go beyond MaxBandwidth to catch up.
• The beginning of a response is allowed to exceed MaxBandwidth. For example, a server may transfer media file at high speed at the beginning in order to expedite playback on the client. For example, if that client needs initial 20KB of the file to start playback, the server might have this variable set to 20KB.

Requirements

See also

HTTP Server API Version 2.0 Structures