Isdn Advanced Settings; Isdn Codec Settings - Cisco TELEPRESENCE ISDN GATEWAYS 2.0 Online Help Manual

ISDN advanced settings

Field
Field description
E1 CRC-4 enabled With an ISDN interface type of E1
selected in the Basic settings, this
option selects whether ISDN
signalling should make use of the
CRC-4 mechanism.
T1 ESF enabled With an ISDN interface type of T1
selected, this option selects whether
ISDN signalling should make use of
the Extended Superframe Framing
technique.
Send channel ID Do not change these settings unless
in Q.931 advised to do so by Cisco customer
Line length support, or if you are an experienced
Line impedance
ISDN administrator.
Line coding
Transmit pulse
shape
National bits
(Sa4..Sa8)
Video NSF
These fields allow you to choose a
Telephone NSF value between 1 and 31, or to leave
the Network Specific Facility disabled
(which is the default behavior and the
implied setting in previous releases of
the ISDN Gateway). Do not change
these settings unless advised to do
so by Cisco customer support, or if
you are an experienced ISDN
administrator.

ISDN codec settings

Field
Field description
Audio codecs Restricts the choice of audio codecs
allowed that endpoints calling through the
ISDN gateway may select. (You
cannot disable the G.711 codec.)
Cisco TelePresence ISDN Gateways v2.0 Online help (Printable format)
Configuring general ISDN settings
Usage tips
Most E1 ISDN networks require CRC-
4 to be enabled, although some (in
particular, some French networks)
require it to be disabled. Refer to your
ISDN network provider if you are
unsure whether to enable or disable
CRC-4.
The ISDN gateway may have to be
restarted for changes of this setting to
take effect (see Shutting down the
ISDN gateway).
Most T1 ISDN networks require ESF
to be enabled. Refer to your ISDN
network provider if you are unsure
whether to enable or disable ESF.
The ISDN gateway may have to be
restarted for changes to this setting to
take effect.
Not all settings apply to all networks.
For example, the National bits are
relevant only for E1 networks.
Setting a value adds a field to ISDN
call setup messages which is required
by some ISDN networks. The two
fields allow for networks in which a
different value is required for video
and telephone calls.
Usage tips
IP and ISDN endpoints negotiate
between themselves which audio
codecs to use during a call. Use these
options if you wish to restrict the
choices available.
Prohibiting audio codecs may prevent
endpoints negotiating a compatible
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