Specifications

Software Upgrade Issues Reference Manual (MGCP/NCS Version)
Mediatrix 4100
181
SOLUTION: Set the Input sound level to -6 dB. If this still does not solve the problem, try the +6 dB value.
See “User Gain” on page 146 for more details.
DESCRIPTION: Unable to send a fax in T.38 and Clear Channel.
 POSSIBLE CAUSE: To properly send faxes, both units must be configured with the same settings. If you
are attempting to send a fax and the transmission fails, there could be many reasons for this, but most
likely the fax codec settings are at fault. The following explains the logic behind fax transmissions.
When transmitting a fax, Unit A first verifies if Unit B supports the codec you have set in Unit A. If the
codec is supported, the fax should be transmitted properly.
If the fax codec is not supported by Unit B, Unit A tries to find a common preferred G.711 clear channel
codec between the two units. If Unit A finds one, it uses this common clear channel codec and the fax
should be transmitted properly. If there are no common clear channel codecs between the units, the fax
transmission fails.
SOLUTION: To avoid fax transmission problems, configure both units with the same T.38 and clear
channel settings and the fax should be sent properly.
DESCRIPTION: Voice does not switch back to the original negotiated codec after a clear channel fax is
performed.
 POSSIBLE CAUSE: The Mediatrix 4100 suffers from a limitation of its DSP. The Mediatrix 4100 cannot
detect the end of a clear channel fax, which means that the unit cannot switch back to the original
negotiated codec if this codec was not a clear channel codec, e.g., a session established in G.729.
When the unit detects a fax, it automatically switches to a negotiated clear channel codec such as
PCMU (if there is no T.38 or if T.38 negotiation failed). Once the fax is terminated, the Mediatrix 4100
is not notified by the DSP. The unit thus stays in the clear channel codec and does not switch back to
G.729.
SOLUTION: There is no solution.
DESCRIPTION: When using the Mediatrix 4100 with the Cyberguard SG530 broadband router, the router
blocks fax transmissions.
 POSSIBLE CAUSE: Cyberguard Version 2.0.2 seems to be the problem.
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OLUTION: Upgrade the Cyberguard to version 2.1.3.
Software Upgrade Issues
The following are issues you may encounter when performing a software upgrade operation.
DESCRIPTION: An error occurs when the Mediatrix 4100 attempts to communicate with the image server.
 POSSIBLE CAUSE: The directory specified in the upgrade command does not exist or does not contain
the files required for the software download process.
SOLUTION:
• Check the directory name.
• Be sure that the directory contains files. If not, extract them from the zip file again. See
“
Download Procedure” on page 118 for more details.