Consolidated Platform Configuration Guide, Cisco Ios Release 15.2(4)E (Catalyst 2960-X Switches - Cisco Catalyst 2960 series Configuration Manual

Information About TACACS+
Cause Description 11.0
Codes
1817 - The called no
Q850 User party is
Busy unable to
accept
another call
because the
user-busy
condition
has been
encountered.
This code
may be
generated
by the
called user
or by the
network. In
the case of
the user,
the user
equipment
is
compatible
with the
call. This
code
applies to
ISDN or
modem
calls that
came in
over ISDN.

Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)

856
11.1 11.2 11.3
no no no
12.0 12.1 12.2
no no no
12.3
yes