This attribute specifies the maximum amount of time that the IWF
may wait following the receipt of any frame requiring a reply before
it initiates transmission of an appropriate reply in order to ensure
that the reply frame is received by the remote error-correcting entity
prior to expiration of the T401 timer of the remote error-correcting
entity. Since information about the T402 timer is not carried in the
Exchange Identification (XID) negotiations at call setup, both sides
operate with different timer values. If this timer expires, then the
reply that would have been returned prior to its expiration is not
sent. The performance of the data link layer can be impacted by the
value of this timer as retransmissions of frames occur on expiry of
timer T401. For better performance, a value of t402AckDelayTimer
(T402) equal to half the value of t401AckTimer (T401) is
recommended.
Changes to this attribute do not effect existing calls.