This attribute specifies the time the receiving Radio Link Protocol
(RLP1) entity shall wait for a response from the peer TIA-136-310
(formerly IS-130) application.
During the Exchange Information (XID) negotiation, both RLP1
entities (mobile station and IWF) can agree to use a specific value
for this timer (T1). The IWF attempts to negotiate to the value
specified by this attribute.
Changes to this attribute do not affect existing calls.