2.2.14.2.3 Network Characteristics Sync (RDP_NETCHAR_SYNC)

The RDP_NETCHAR_SYNC structure is sent in response to the RTT Measure Request (section 2.2.14.1.1) message or Bandwidth Measure Start (section 2.2.14.1.2) message and is used to short-circuit connect-time network characteristics detection in the case of an auto-reconnect (section 1.3.1.5 and 2.2.4).


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headerLength

headerTypeId

sequenceNumber

responseType

bandwidth

...

rtt

...

headerLength (1 byte): An 8-bit unsigned integer that specifies the size, in bytes, of the header data. This field MUST be set to 0x0E.

headerTypeId (1 byte): An 8-bit unsigned integer that specifies the high-level type. This field MUST be set to TYPE_ID_AUTODETECT_RESPONSE (0x01).

sequenceNumber (2 bytes): A 16-bit unsigned integer that specifies the message sequence number. This field SHOULD be set to the same value as the sequenceNumber field of the most recent RTT Measure Request (section 2.2.14.1.1) or Bandwidth Measure Stop (section 2.2.14.1.4) message received from the server.

responseType (2 bytes): A 16-bit unsigned integer that specifies a request type code. This field MUST be set to 0x0018.

bandwidth (4 bytes): A 32-bit unsigned integer that specifies the previously detected bandwidth in kilobits per second.

rtt (4 bytes): A 32-bit unsigned integer that specifies the previously detected round-trip time in milliseconds.