The Ozeki VoIP Service Checker is a tool you can use for checking
the availability of VoIP services. It can be used to verify if a given service exists,
whether it can be reached from a particular network and it checks if the user details,
such as the username and password to access that service is correct. This tool was developed
because many mobile Internet providers block VoIP traffic and no other tool
exists that makes it possible to quickly verify if a certain network support VoIP.
The tool is as made available to the
public free of charge with the GPL license.
The tool is open source. The source code is provided
for different platforms. You are free to use, modify, develop
or do whatever you wish with this tool.
How does the VoIP Service checker work?
Figure 1 - The Ozeki VoIP Service Checker in operation
The Ozeki VoIP service checker checks the availability of a VoIP service
by sending a VoIP login packet to the PBX and it waits for a response.
The login packet is an UDP packet formatted according to the SIP protocol.
If the PBX receives the VoIP login packet it sends a response message telling
wether the login information was correct or not. If no response message is received
it indicates that the PBX is not available or the Internet service provider
blocks VoIP packet. If a response is received the status of the response indicates
if the login information is correct or not. The VoIP service checker tool
displays the result.