RESPTIME

Command

RESPTIME -- Display / Set L2 delayed ack timer for port.

Synopsis

RESPTIME <port> [millisecs]

Description

The RESPTIME command allows the value of the AX25 T2 (delayed ack) timer for a port to be displayed or altered.

Options

If a single numeric argument is supplied, the current value for that port number is displayed.

If two numeric arguments are supplied, the first specifies the port number, and the second specifies the new value for the parameter. The new setting remains in force until changed, or until the router is restarted, in which case the value specified in the CFG file is reapplied.

Examples

RESPTIME 3       - Display current setting for port 3
RESPTIME 3 150   - Set port 3 resptime to 1500 millisecs

Notes

The RESPTIME parameter specifies how long the router will wait, after receiving a frame, before sending an ack for that frame. It helps to improve the efficiency by cutting out unnecessary acks. It allows a single ack to be sent when a transmission contains several frames, instead of acking each frame in turn.

The value must therefore be at least the length of time it takes to transmit a single packet. At 1200 bauds (120 bytes/sec) a 120 byte packet lasts 1 second, a 180 byte packet lasts 1500 millisecs and a 256 byte packet lasts just over 2 secs. Therefore resptime should reflect the paclen used by the sender. 1500 millisecs is a good compromise, but if the other end regularly uses high paclens, 2000 or 2500 ms would be more appropriate.

At 9600 baud, or on AXUDP links, 200 millisecs is probably adequate.

Too high a value will cause the link to be too "relaxed", whereas too low a value will cause too many acks. Both extremes reduce the link efficiency.

Availability

This is a sysop-only command.

See also

FRACK(2)
SLOTTIME(2)