I can’t receive incoming calls


If you use a NAT or firewall that cannot be handled automatically by MizuPhone, you can explicitely set the listening SIP and RTP ports on the sofphone, then configure your device (router, NAT or firewall) to route the requested ports to your softphone. (setup a virtual server configuration). You usually have to route the default SIP port (5060) and some RTP ports (for example between 50000 and 50005)


How to call other UA directly (bypassing the sipserver)


Switch to the Dial page.

Enter the “phone number” in the following format:


for example:


(if you omit the port, the default port will be 5060)


The voice are cutting. How can I improve the voice quality?

  • Enable the silence detection
  • Increase the jitter buffer
  • Use a low bandwidth codec
  • Make sure that some other program don’t eat all of your CPU time
  • Make sure you have at least 10 kbits/sec upload and download.



The best quality builtin codec is SpeexUWB (speex ultra wideband), but in order to be used, your peer must also have this codec. PSTN calls don’t have wideband codecs, because their characterisitcs. For this codec to work properly, you will need a quality 45 kbits upload and download (29 kbits for raw codec payload + rtp and udp payload + some signaling). To achieve the best quality, you must use a headset. If you hear noise, enable noise supression. If you hear cutting voice, check this FAQ.



Go to File Menu -> Settings -> Codecs (activate the “Show advanced settings” if you don’t see codecs).

Set the priority for your codec to the lovest value. (0=highest priority, 100=lowest priority)

Eventually you can disable all other codecs (uncheck the “Use this codec” checkbox; but in this case, calls may fail if the remote endpoint don’t have the selected codec)


What is VoIM?


Voice over Instant Messaging (VoIM) presents VoIP as one communication mode among several, with an IM user interface (contact list and presence) as the primary user experience. Many instant messenger services added client-to-client or client-to-PSTN VoIP in the mid-2000s.


What can a MizuPhone do that a landline phone cannot?


A VoIP or broadband phone service can help you save up to 90% of your monthly phone bill. VoIP providers offer many features which are covered in the monthly fee, such as voicemail, caller ID, three-way calling, and call waiting. Many providers offer unlimited long-distance with their plans, which saves customers the trouble of having to purchase long-distance phone cards. Furthermore, most providers offer unlimited calling to other subscribers of the same service, allowing you to talk to those users for as long as you wish at no additional cost. VoIP service is best suited for you if you can relate with any of the following comments:
- "I have a high speed internet connection and would like to lower my phone bills."
- "I make expensive long-distance or international calls and would like to reduce those costs."
- "I run a small business and phone bills make significant part of my overhead."
- "I like the convenience of taking my number with me as I travel anywhere in the world."
- "I'd like to utilize attractive features such as conference calling, choice of any area code, voice mail, caller ID, call waiting, etc."
- "I'm frustrated with excessive taxes and long-distance company monopolies."
- "I live outside the U.S. but I need a local NYC number for my business."


If I have VoIP service, who can I call?


Depending upon your service, you might be limited only to other subscribers to the service, or you may be able to call anyone who has a telephone number - including local, long distance, mobile, and international numbers. If you are calling someone who has a regular analog phone, that person does not need any special equipment to talk to you. Some VoIP services may allow you to speak with more than one person at a time.


MizuPhone profiles


Your profile means your data, settings, contact list and history archives.
You need to protect these data if you share your computer with others or when using mizuphone from a public location.
With mizuphone you can protect these sensitive data with a username and password which is requested on the login form.
Enter any username and password and your data will be encrypted and safe.
In costumized softphone versions the username and password you enter on the login form will automatically be used for authentication by your service provider.
Your profile can be stored on a public server, so when you sit at another computer your settings and contactlist can be downloaded and you don't have to type it again.
If you don't need this feature, than just check the "Login automatically" checkbox to get rid of the login form.


What is "Click to call"?


Click-to-call or Click-to-Talk is a service which lets users click a button on a company website and immediately speak with a customer service representative. The call can either be carried over VoIP, or the customer may request an immediate call back by entering their phone number. One significant benefit to click-to-call providers is that it allows companies to monitor when online visitors change from the website to a phone sales channel.


The called party hang up immediatly after pick up the phone


Disable SIP Settings -> Allow forked requests


The called has 2 incoming calls for one session


Disable SIP Settings -> Allow forked requests


I want to learn more about VOIP...


Check out these VOIP tutorials:

VOIP Tutorial
What is SIP
VOIP definition
Using VOIP



When you check the “Remember my password” checkbox, your password will be saved.

To delete the saved password, just click on File menu -> LogOff (for example when you leave a public internet location)


What is VOIP?


With the help of VOIP you can replace your old style phones and upgrade to a more advanced form of communication.
    -lower prices
    -more flexibility
    -better sound quality
    -instant messaging
    -video conference
    -and many other things to improwe the way you communicate

Voice over Internet Protocol (VoIP) - technology that enables one to make and receive phone calls thru the Internet instead of using the traditional analog PSTN (Public Switched Telephone Network) lines. VoIP services convert your voice into a digital signal that travels over the Internet. If you are calling a regular phone number, the signal is converted to a regular telephone signal before it reaches the destination. VoIP can allow you to make a call directly from a computer, a special VoIP phone, or a traditional phone connected to a special adapter. In addition, wireless "hot spots" in locations such as airports, parks, and cafes allow you to connect to the Internet and may enable you to use VoIP service wirelessly.


MizuPhone profile storage


Your profile can be stored on a public server, so when you sit at another computer your settings and contactlist can be downloaded and you don't have to type it again.
With Skype, MSN, Yahoo, etc this thing is very obvious, but with mizuphone you are free to choose your provider(s) and your central profile location, so it will require a little time to set-up, but it is more secure
If you don't have access to such a central storage location, then create a free mizutech account because mizutech will give your profile storage on their servers for free.
Your profile is encrypted except when using advanced XCAP storage option, when the server will manipulate your profile and thus it cannot be encrypted by default.