Aastra MBU 400 User Manual page 63

Issue (Continued)
There is no audio when I make
Internet calls.
I cannot make landline calls.
I cannot receive landline calls.
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.
When I make Internet calls, the
sound quality is poor.
Aastra MBU 400 User Guide
VoIPon www.voipon.co.uk sales@voipon.co.uk Tel: +44 (0)1245 808195 Fax: +44 (0)1245 808299
Causes (Continued)
The router blocks audio.
The landline cable is not connected. Check that the landline cable between
The landline is out of order.
The country setting is wrong.
The configuration of the phone is
not complete.
The MBU has not been reset after
you saved the configuration.
The router uses port forwarding.
The router blocks Internet
telephony.
The router firmware needs updating. Check your router's user manual to see
There is too much simultaneous
data traffic on your broadband
connection.
Your Internet Telephony Service
Provider's Quality of Service is
based on a "best efforts" rather than
a guaranteed voice priority method.
Solution (Continued)
Use port forwarding. Check your router's
user manual to see how to configure port
forwarding.
the Line port on the MBU and the
telephone wall outlet is connected
properly.
Contact your landline provider.
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.
Check that you have configured your
phone properly. See Configuring Your
Phone for First-Time Use on page 22.
For more information, contact your
Internet Telephony Service Provider or
your System Administrator.
Reset the MBU and allow the MBU 2
minutes to log in at your Internet
Telephony Service Provider.
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.
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.
how to update the firmware.
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.
Contact your Internet Telephony Service
Provider regarding ensured voice
prioritization across the network.
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