3Com 3C10402B Administrator's Manual page 174

174 C 8: PSTN G
HAPTER
C
ATEWAY ONFIGURATION
Some telephone companies offer Partial E1and T1 lines as their standard
offering, and provide fully implemented E1 and T1 lines only if you make
a specific request. If you are unaware of this policy, outbound calls using
the E1 or T1 line might fail because, by default, the system places
outbound calls using high numbered channels first, and a Fractional E1 or
T1 typically has the lower numbered channels implemented.
If you see the REQ_CHANNEL_UNAVAIL error message in the span Status
window under the Details of last five calls heading, follow these steps to
determine if a Partial E1 or T1 is causing the error:
1 Remove the highest numbered channel from service (set it offline) and
retry the outbound call. See
information about how to modify a channel
2 Continue to remove channels until an outbound call succeeds.
3 When the first outbound call succeeds, the highest numbered channel
still in service represents the number of active (provisioned) channels in
the Partial E1 or T1.
4 Create two groups. Put all of the active channels in one group, and all of
the inactive channels in the other. Mark the active group online and the
inactive group offline. See
on page 177 for more information about creating groups.
Modifying Span Audio Controls
Normally, you do not need to change the Audio Controls from their
default settings. If you have a problem with sound quality that you
cannot resolve by using the volume controls on the 3Com telephones,
contact your 3Com Technical Support representative.
CAUTION: Do not change your Audio Controls settings unless a qualified
technical support representative instructs you to do so.
Audio Controls settings affect individual spans. You can edit these
properties:
Silence Suppression (3C10165D cards only) — Enables you to override
■
the system-wide setting. For a detailed description of how silence
suppression affects audio quality and bandwidth, see
Settings" on
Audio Compression (3C10165D cards only) — Enables you to override
■
the system-wide setting. For a detailed description of how audio
Modifying Card Channels
Adding or Modifying a Digital Line Card Group
page 37.
on page 180 for
"Audio