Appendix A-Disconnection Causes

A-10

ISDN Disconnection Causes
Table A-2 ISDN Disconnection Causes
Disconnection Cause
Number Summary Description
1Unallocated
(unassigned
number)
No route to the number exists in the ISDN
network or the number was not found in the
routing table.
•Ensure that the number appears in the
routing table.
•Ensure that it is a valid number and that
correct digits were dialed.
2No route to
specified transit
network
(national use)
The route specified (transit network) between
the two networks does not exist.
3No route to
destination
No physical route to the destination number
exists although the dialed number is in the
routing plan.
•The PRI D-Channel is malfunctioning.
•Incorrect connection of the span or WAN.
4Send special
information tone
Return the special information tone to the
calling party indicating that the called user
cannot be reached.
5Misdialed trunk
prefix (national
use)
A trunk prefix has erroneously been included in
the called user number.
6Channel
Unacceptable
The sending entity in the call does not accept
the channel most recently identified.
7Call awarded
and being
delivered in an
Established
channel
The incoming call is being connected to a
channel previously established for similar calls.