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Configuring ISDN ports settings (non-leased line mode)
Cisco TelePresence ISDN Gateways v2.0 Online help (Printable format)
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Channel
search order
Select whether free B-channels should
be selected starting with the low-
numbered channel and working towards
the high-numbered channel, or the other
way around.
When making outgoing ISDN calls, the
ISDN gateway requests that the ISDN
network makes the call using a
particular set of B-channels; when
receiving incoming ISDN calls, the ISDN
network informs the ISDN gateway
which B-channels are in use.
To minimize the risk of a new incoming
call using the same B-channels as a
new outgoing call starting at the same
time, you should generally set the ISDN
gateway to search free channels in the
reverse order to the ISDN network.
Refer to your ISDN network provider if
you are unsure of which value to use
here.
Allow NFAS
Select to enable Non-Facility Associated
Signaling (NFAS).
This setting is only visible when the
ISDN gateway is configured to use T1
as the
ISDN interface type
. To configure
the ISDN
interface type
, go to
Settings
> ISDN
.
NFAS allows multiple PRIs (in T1 mode)
to use a single D-channel. The NFAS
settings on the ISDN gateway must
match the settings on the ISDN switch
to which the ISDN gateway is
connected.
NFAS group
ID
Select an ID for the NFAS group.
Allocate the same NFAS group ID to
each port that will use the same D-
channel. Ports with the same NFAS
group ID are in the same NFAS group.
NFAS
interface ID
Select an ID for the NFAS interface.
Within the NFAS group, each NFAS
interface ID must be unique, must be
between 0 and 31, and must be the
same as that set on the switch to which
the ISDN GW is connected.
D-channel
type
Select the D-channel type.
Within the NFAS group, one port must
have the D-channel type set to Primary
(active) and the other ports must have
D-channel type set to None. This must
match the settings on the switch.