Cheap VOIP with Skype and SipToSis

Posted by Max Power | Posted in VOIP | Posted on 06-12-2010-05-2008


Imagine having VOIP phone service using your existing home phones for about $3/month.

I am using Skype as my VOIP provider which costs about $3.00/month and SipToSis to provide a Skype gateway to a Linksys SPA-3102 where I connect a regular cordless home phone.  I have been using this for a few months now and have had no problems.  In this article I will give the details of my setup.


Skype provides the VOIP service for a low monthly payment but lacks the ability to connect to a regular home phone.  Skype can be installed on a windows or linux server.  I am using a desktop computer that also acts as my media server and DVR so it is on all of the time.


SipToSis is a little java application that interfaces with Skype and provides a gateway allowing you to connect a regular Sip device to Skype. You can download the application here and there are setup instructions here.


XYNTService is used to install Skype and SipToSis as a service so that it starts when the computer is started.  In order to make this work I had to allow the user “Log on as Service”.  Here is the ini file that I used:


ServiceName = SipToSis
CheckProcessSeconds = 300
CommandLine = "java.exe -Xms24m -Xmx24m -Djava.library.path=. -classpath tritonus_gsm-0.3.6.jar;tritonus_share-0.3.6.jar;jmf.jar;jspeex.jar;sip.jar;ua.jar;mailapi.jar;smtp.jar;activation.jar;skype.jar;log4j-1.2.15.jar;siptosis.jar;."
WorkingDir = "C:\VOIP\SipToSis_20101005"
PauseStart = 1000
PauseEnd = 1000
UserInterface = No
Restart = Yes
UserName = user
Domain =
Password = pass

CommandLine = "C:\Program Files\Skype\Phone\Skype.exe /minimized"
WorkingDir = "C:\Program Files\Skype\Phone"
PauseStart = 1000
PauseEnd = 2000
UserInterface = Yes
Restart = Yes
UserName =
Domain =
Password =

Install the service (XYNTService -i) then start it and check the SipToSis log file (.\log\SipToSis.log) and make sure that it was allowed to connect (you may have to open skype and allow the connection).

Sip Adapter

I am using a Linksys SPA-3102 which has a FXO port (connection to external regular phone line), a FXS port (allows you to connect the house phones), and two Ethernet ports (external net and internal net).  This is a router and phone adapter in one.  This adapter allows you to use the VOIP when it is available and the regular phone line when VOIP is not available.  In addition, both phone lines, the regular line and the VOIP line will ring to the FXS port. This link provides information about the difference between the different adapters.

Comments posted (3)

Dear Friend
I wonder if your settings allows you to receive PSTN call on your Skype client.
I have the SPA 3102, the SiptoSis installed but I can’t make Skype rings when I receive a PSTN call. That’s the solution I’m looking for. If you can, please leet me know if it works for you and, please, send me your configuration both for SPA3102 and Siptosis.
I’m trying it for 02 weeks know with no sucess.
My best regards

I have paid for a Skype phone number for incoming calls. This is how I receive PSTN calls and this is also why I say that the solution is cheap and not free. The Skype phone number cost about $30/year for the number and $3/month for the service. I have not yet been able to find a good/reliable way to circumvent this piece of the puzzle.

Thanks for your reply.
Yes, I have some SkypeIn numbers but I need to use one especific line out here.
But thanks anyways and congrats for your post

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