ACC X.25 Protocol User's Guide

ZX25D X.25 Protocol Driver
Configuration
Chapter 3 37
T1_timer Optional override configuration for T1. If this
parameter is not supplied, T1 is set from the Select
Word configured for the Link terminal. If this
parameter is supplied then other options and
configuration parameters have no affect on the T1
timer. Two parameters must be supplied with this
keyword, the resolution (one of: res_10ms, res_100ms,
res_1s, or res_10s) and the multiplier (an integer in the
range 2 to 255).
T2_timer Optional override configuration for T2. If this
parameter is not supplied, T2 is set from the Select
Word configured for the Link terminal. If this
parameter is supplied then other options and
configuration parameters have no effect on the T2
timer. Two parameters must be supplied with this
keyword, the resolution (one of: res_10ms, res_100ms,
res_1s, or res_10s) and the multiplier (an integer in the
range 2 to 255).
T3_T4_timer Optional override configuration for T3/T4. If this
parameter is not supplied, T3/T4 is set automatically,
depending on the “DCE/DTE” and “T3” options. If this
parameter is supplied then other options and
configuration parameters have no affect on the T3/T4
timer. Two parameters must be supplied with this
keyword, the resolution (one of: res_10ms, res_100ms,
res_1s, or res_10s) and the multiplier (an integer in the
range 2 to 255). If the Link is configured as a DTE then
this parameter sets the T4 timer. If the Link is
configured as a DCE then this parameter sets the T3
timer.
NOTE The ITU-T specification states that T1 should be greater than T2, and
that T3/T4 should be much greater than T1 or T2 (e.g. 10 times T1 or T2).
If these rules are not observed, the HDLC/LAP-B (X.25 Level 2) may not
operate correctly.
T1 should have a value at least twice the time it takes to transmit the
largest possible X.25 packet. This is dependent on the baud rate
configured and the largest potential X.25 level 3 packet size configured.