C
AUSE
C
ODES
T
ABLE
The following table provides Q.931 cause codes and their corresponding meanings. Cause codes
may appear in Call Trace Messages.
Dec Value
Hex Value
Q.931 Cause
0
0
valid cause code not yet received
1
1
unallocated (unassigned number)
Indicates that, although the ISDN number was presented in a valid
format, it is not currently assigned to any destination equipment.
2
2
no route to specified transit network (WAN)
Indicates that the ISDN exchange was asked to route the call through
an intermediate network that is unrecognized.
3
3
no route to destination
Indicates that the call was actually routed through a network that
does not serve the destination address.
4
4
send special information tone
5
5
misdialed trunk prefix
6
6
channel unacceptable
Indicates that the quality of service provided by the specified
channel was insufficient to accept the connection.
7
7
call awarded and being delivered in an established channel
Indicates that the device has been awarded an incoming call and that
the call is being connected to a channel that has already been
established for similar calls.
8
8
prefix 0 dialed but not allowed
9
9
prefix 1 dialed but not allowed
10
A
prefix 1 dialed but not required
11
B
more digits received than allowed, call is proceeding
16
10
normal call clearing or normal disconnect
Reports the normal clearing of a call. No action required.
17
11
device busy
Indicates that the called system has acknowledged the connection
request, but is unable to accept the call because the B-channels are
currently in use.
18
12
no device responding
Indicates that the connection could not be completed because the
destination failed to respond to the call.
