LXE MX1-IS, Справочное руководство

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88 SOCKETS TCP/IP Stack
MX1 I-Safe Reference Guide E-EQ-MX1ISRG-F
tcp
tcp commands display or set various TCP operating parameters. The TCP configuration
commands are put into SOCKET.CFG.
Syntax
tcp irtt [time]
tcp lport [port_number]
tcp mss [size]
tcp retry [number]
tcp rtt [time]
tcp smss [size]
tcp timemax [time]
tcp window [size]
Parameters
time
time is the new time value in seconds, or milliseconds if “ms” is appended to the number, as in
2000ms.
port_number
port_number is the local port starting number.
size
For tcp mss, size is the maximum segment size in bytes sent on all outgoing TCP connect requests
(SYN segments). size tells the remote host the size of the largest segment that may be received by
this host. When changing the MSS value, any existing connections remain unchanged.
For tcp smss, size is the send maximum segment size in bytes sent on all outgoing TCP connect
requests. This limits the size of the largest segment that may be sent by this host. When changing
the SMSS value, any existing connections remain unchanged.
For tcp window, size is the size of the receive window in bytes for any new TCP connections.
Existing connections are unaffected.
number
number is the number of retries attempted without receiving an acknowledge from the remote host
before the connection is broken. If the value exceeds 255, it implies an infinite number of retries;
such a connection does not time-out. The default value for
number is 6.
tcp irtt Sub-command
tcp irtt displays or sets the initial round-trip-time estimate. When specified without an argument,
the command displays the current values of TCP parameters including the initial round-trip-time
in milliseconds.
time is the initial round-trip-time (IRTT) estimate and is used for new TCP connections until the
actual value can be measured and adapted to. By increasing this value when operating over slow
communication links, unnecessary retransmissions that otherwise occur before the smoothed
estimate value approaches the correct value are minimized. The system default is 5000
milliseconds.