ZyXEL Communications V501-T1 User Manual
Page 232
Chapter 17 Troubleshooting
V500 Series User’s Guide
232
V
I can make phonecalls, but I cannot receive them.
or
I can receive some phonecalls, but not others.
Check your V500’s call forwarding settings (see
). If they are
misconfigured, certain calls may be mistakenly forwarded.
V
All my VoIP calls are of poor audio quality.
• If your ISP or network administrator gave you SIP TOS or RTP TOS values to use, enter
them in the web configurator’s VoIP > SIP > QoS screen (see
• If your V500 is connected to a router with configurable bandwidth management settings,
check these settings. Consult the router’s documentation for more information.
• Make sure that your V500 uses the voice codecs recommended by your VoIP service
V
I cannot use some calling features.
Many of the features your V500 supports depend on your VoIP service provider. You may
have to subscribe to certain services. Contact your VoIP service provider for more
information.
V
The incoming or outgoing audio is too quiet or too loud.
or
I cannot hear the V500’s ring when a call is incoming.
Use the VOLUME keys to increase or decrease the volume.
• When no audio device (the handset, speakerphone or an external headset) is active, the
VOLUME keys control the ringing volume.
• When an audio device is active, the VOLUME keys control the input and output of that
device.