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Configuring general ISDN settings
Cisco TelePresence ISDN Gateway 2.1 Online help (Printable format) 75 of 135
Line length
Line impedance
Line coding
Transmit pulse
shape
National bits
(Sa4..Sa8)
customer support, or if you are an
experienced ISDN administrator.
relevant only for E1 networks.
Video NSF
Telephone NSF
These fields allow you to choose a
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.
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.
ISDN codec settings
Field
Field description Usage tips
Audio codecs
allowed
Restricts the choice of audio codecs
that endpoints calling through the
ISDN Gateway may select. (You
cannot disable the G.711 codec.)
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
codec; use these options only if you
experience a particular problem when
using a certain codec with the ISDN
Gateway. If the IP endpoint is a Cisco
TelePresence MCU or IP VCR,
consider disabling the codec on that
device instead.
Video codecs
allowed
Restricts the choice of video codecs
that endpoints calling through the
ISDN Gateway may select. (You
cannot disable the H.261 codec.)
IP and ISDN endpoints negotiate
between themselves which video
codecs to use during a call. Use these
options if you wish to restrict the
choices available.
Prohibiting video codecs may prevent
endpoints negotiating a compatible
codec; use these options only if you
experience a particular problem when
using a certain codec with the ISDN
Gateway. If the IP endpoint is a Cisco
TelePresence MCU or IP VCR,
consider disabling the codec on that
device instead.
Note that H.263 also encompasses
H.263+.
Content video
Restricts the choice of content IP and ISDN endpoints between