ZyXEL Communications V300 - Manual (Page 151)

Chapter 16 Troubleshooting
V300 User’s Guide
151
2 Check your DNS SRV settings for the SIP account you want to use (see Section 6.3.13
on page 78 ). If DNS SRV is turned off, turn it on.
3 Make sure that your V300 uses the voice codecs recommended by your VoIP service
provider (see Section 6.3.11 on page 77 ).
V
I can make some VoIP calls, but not others.
The V300’s DNS (Domain Name Service) settings may be misconfigured. See the suggestions
about DNS in the troubleshooting section for “
I cannot make VoIP calls. ”.
If this does not help, the phone of the person you are calling may be malfunctioning or
misconfigured.
V
I can make phonecalls, but I cannot receive them.
or
I can receive some phonecalls, but not others.
Check your V300’s call forwarding settings (see Section 5.4.2 on page 55 ). 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 Section 10.3 on page 117 ).
• If your V300 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 V300 uses the voice codecs recommended by your VoIP service
provider (see Section 6.3.11 on page 77 ).
V
I cannot use some calling features.
Many of the features your V300 supports depend on your VoIP service provider. You may
have to subscribe to certain services. Contact your VoIP service provider for more information.