Aastra Telecom 41-001286-00 Manuale Utente

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Aastra MBU 400 User Guide
 63
Troubleshooting
There is no audio when I make 
Internet calls.
The router blocks audio.
Use port forwarding. Check your router’s 
user manual to see how to configure port 
forwarding.
I cannot make landline calls.
The landline cable is not connected.  Check that the landline cable between 
the Line port on the MBU and the 
telephone wall outlet is connected 
properly.
The landline is out of order.
 Contact your landline provider.
I cannot receive landline calls.
The country setting is wrong.
Check that you have chosen the country 
that you are in. Open the System 
settings menu, choose Country 
selection, and then choose the country 
that you are in.
I cannot make Internet calls, the 
VoIP indicator on the MBU is not 
lit, and the right status indicator 
in the upper left corner of the 
display is black.
The configuration of the phone is 
not complete.
Check that you have configured your 
phone properly. Se
.
For more information, contact your 
Internet Telephony Service Provider or 
your System Administrator.
The MBU has not been reset after 
you saved the configuration.
Reset the MBU and allow the MBU 2 
minutes to log in at your Internet 
Telephony Service Provider.
The router uses port forwarding.
Check that you have configured your 
router so that it always assigns the same 
IP address to your phone’s MAC address 
when using port forwarding. Otherwise 
incoming traffic is probably not forwarded 
to your phone. For more information, 
check your router’s manual.
The router blocks Internet 
telephony.
Use port forwarding. The default SIP port 
is 5060, and the default RTP port is 
5004. Ensure that your router always 
assigns the same IP address to your 
phone when using port forwarding.
For more information, check your 
router’s manual.
The router firmware needs updating. Check your router’s user manual to see 
how to update the firmware.
When I make Internet calls, the 
sound quality is poor.
There is too much simultaneous 
data traffic on your broadband 
connection.
 a) Reduce the amount of traffic on your 
broadband connection.
b) Sign up for a Quality of Service 
agreement with your broadband 
provider.
c) Order a connection with higher speed 
from your broadband provider.
Your Internet Telephony Service 
Provider’s Quality of Service is 
based on a “best efforts” rather than 
a guaranteed voice priority method.
Contact your Internet Telephony Service 
Provider regarding ensured voice 
prioritization across the network.
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