TCP_INFO_v0 structure (mstcpip.h)
Contains the Transmission Control Protocol (TCP) statistics that were collected for a socket.
Syntax
typedef struct _TCP_INFO_v0 {
TCPSTATE State;
ULONG Mss;
ULONG64 ConnectionTimeMs;
BOOLEAN TimestampsEnabled;
ULONG RttUs;
ULONG MinRttUs;
ULONG BytesInFlight;
ULONG Cwnd;
ULONG SndWnd;
ULONG RcvWnd;
ULONG RcvBuf;
ULONG64 BytesOut;
ULONG64 BytesIn;
ULONG BytesReordered;
ULONG BytesRetrans;
ULONG FastRetrans;
ULONG DupAcksIn;
ULONG TimeoutEpisodes;
UCHAR SynRetrans;
} TCP_INFO_v0, *PTCP_INFO_v0;
Members
State
A value from the TCPSTATE enumeration that indicates the state of the TCP connection.
Mss
The current maximum segment size (MSS) for the connection, in bytes.
ConnectionTimeMs
The lifetime of the connection, in milliseconds.
TimestampsEnabled
TRUE if TCP time stamps are turned on for the connection; otherwise FALSE.
RttUs
The current estimated round-trip time for the connection, in microseconds.
MinRttUs
The minimum sampled round trip time, in microseconds.
BytesInFlight
The current number of sent bytes that are unacknowledged.
Cwnd
The size of the current congestion window, in bytes.
SndWnd
The size of the send window (SND.WND in RFC 793), in bytes.
RcvWnd
The size of the receive window (RCV.WND in RFC 793), in bytes.
RcvBuf
The size of the current receive buffer, in bytes. The size of the receive buffer changes dynamically when autotuning is turned on for the receive window.
BytesOut
The total number of bytes sent.
BytesIn
The total number of bytes received.
BytesReordered
The total number of bytes reordered.
BytesRetrans
The total number of bytes retransmitted.
FastRetrans
The number of calls of the Fast Retransmit algorithm.
DupAcksIn
The total number of duplicate acknowledgments received.
TimeoutEpisodes
The total number of retransmission timeout episodes. Each episode can consist of multiple timeouts.
SynRetrans
The total number of retransmitted synchronize control flags (SYNs).
Remarks
To get an instance of this structure, call the WSAIoctl or LPWSPIoctl function with the SIO_TCP_INFO control code. Specify 0 for the lpvInBuffer field to retrieve the v0 version of this structure.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows 10, version 1703 [desktop apps only] |
Minimum supported server | Windows Server 2016 [desktop apps only] |
Header | mstcpip.h |