Technical Questions and Answers
This list is divided into two sections: Technical and troubleshooting FAQ's. There is also a general FAQ page for commercially related questions. If you have any questions that haven't been answered here then please contact us.
Technical questions are principally concerned with the technical resources available on this site. For queries about the protocol itself, Columbia University has one of the best technical FAQ areas and is linked here for your convenience. There may be some overlap on FAQ's where the SIPCenter and Columbia University have responded to a common question.
Technical FAQ's
The IP address for sip.sipcenter.com (80.248.35.37) will become 212.187.177.228 from 24th February 2006. If necessary, please adjust your configuration settings accordingly.
How do I register to test my User Agent with the SIP Center's SIP Application Server?
In the Test Bed Area section of this website there is a link to the e-mail registration form. Once this form has been submitted then we will send you a license key and password, as long as your User Agent is compatible with the proxy server. If there are any compatibility issues then our technical department will contact you.
What features does the SIP Application Server have? Can I control them?
We have a stateful, forking proxy server. At the present time an external user cannot directly configure the proxy server; if you want the server configured a certain way then you will need to contact us and you will be given a time when the server will be so configured.
I want to test a particular scenario; can the SIP Center set the scenario up? Yes. The SIP Center aims to advance SIP through the promotion of inter-operability testing. For basic scenarios the resources made available should allow you to easily set up tests. For more advanced scenarios the SIP Center is happy to dedicate resources and try to co-ordinate activities. Please contact us to discuss any requirements.
My User Agent does not seem to communicate well with the SIP Center's server. What help can you offer me?
Please use either the forum area or send an email to SIP Center Support to advise the SIP center of the problem you have encountered and expect a response within 4 working days as to a suggested approach to resolve interoperation.
I want to test a feature that the SIP Center's server does not support. How do I request that this feature be implemented in a future version of the Proxy?
Please use either the forum area or send an email to the SIP Center to advise the SIP Center of additional features. Expect a response within 4 working days as to what can be achieved within a defined timeframe.
Troubleshooting FAQ's
Using MSN Messenger 4.6 on The SIP Center proxy.
At present it is not possible to link MSN Messenger 4.6 via The SIP Center proxy as this client does not support SIP Authentication.
Can't add license-key
Click here, fill in the form and a new license key will be sent to you that will be valid until 31st December, 2007.
Still can't add license-key:
The best practice is to copy the license key from the email and paste it into the 1st left-hand side field of the license key page.
Still can't add license-key:
Is your machine NT4 based? The User Agent is free download designed as a test tool for SIP in labs, it was not intended for commercial use and as such you need to be an administrator / member of administrator group / local administrator or member of local administrator group to run it if it was installed as one of the above.
Still can't add license-key:
Email: support@sipcenter.com
Why do I get "not a valid windows application" when trying to install the User Agent download?
This is possibly a corrupt download of the installation file. Please download the User Agent again from the web site and retry. Make sure there are no policies on your system that restrict the installation of software. Try the install file on a different system to verify that the downloaded file is not corrupt.
Why do I get "bad command or file name" when trying to run the User Agent?
You need Java Runtime 1.3.0 installed in order for the User Agent to work. You can download it from here. To check what version you have installed type "java-version" at the command prompt. Java Development kit 1.3 can also be used instead of the Runtime version.
Why do I get "Exception in thread "main" java.lang.NullPointerException" when trying to run the User Agent?
This is most likely that you have an earlier version than 1.3.0 of Java Runtime installed. You need Java Runtime 1.3.0 installed in order for the User Agent to work. You can download it from here. To check what version you have installed type "java-version" at the command prompt.
Or
You may have specified an INVALID IP address in the UA setup for the program. You need to post-edit the UA.bat file to have the proper IP address. e.g. java -jar ua.jar 192.168.0.131 sip:MyPC@192.168.0.131.
I get web site not found when trying to connect to http://localhost:4080, why?
In order to connect to http://localhost:4080 the User Agent MUST be running. To start the User Agent please refer to the readme.txt file that came with the download. Also try using the loop back IP address http://127.0.0.1:4080 or the actual IP address of the machine you are using (Please refer to the InstallGuide.pdf file that came with the download to find this out).
I get "You entered a duplicate or invalid key." When trying to license the User Agent.
This will happen if you enter a wrong code. Check the code and try again. This will also happen if you try entering the same code as is already registered. If you still have a problem please request a new license key from support@sipcenter.com.
When I start the User Agent it says my "Audio device is in use", why?
This message is usually displayed if another application is using your sound card. Make sure that no other applications are using the sound card. Also, make sure your sound card is configured and working correctly before attempting to run the User Agent. To do this use a simple application such as Sound Recorder (In Windows) and record and playback a simple message. Make sure that you are not using a WAVE device for a modem and that it is not selected as the preferred device in Control Panel/Multimedia.
I want to register on sip.sipcenter.com but I am behind a Firewall, do I need to do anything special?
Yes. You will have to get the administrator of your Firewall to allow access through the firewall on port 5060 (default port on server for registrations etc). If you want to use audio through the Firewall you will need to enable port 5004.
I can't read the Installation notes that came with the download on the User Agent.
You will need Adobe Acrobat Reader 4.0 in order to read the configuration notes. This can be downloaded here.
The User Agent takes a long time to load and my machine runs really slow.
You need a machine of the following specifications in order for the User Agent to run efficiently: A Pentium II 400 Mhz processor with 64 MB RAM and 50 MB Disk Space available.
When I try and connect to the SIP Server (sip.sipcenter.com) I get an authentication box pop up.
Before you can use the sip.sipcenter.com SIP Server you have to register for a Username and Password. Click Here
If you have read through all documentation and this FAQ and still have a problem configuring or running the User Agent, please contact support@sipcenter.com . Please included any logs including the startup log (weekday.log) and the actual call log (CallLog_weekday.log). This will help us in diagnosing any problems as quickly as possible.
What is the installation error message "Unable to install JRE 1.3.0 on your system"
You need to download and install either SDK1.3 (Java Development Kit) or JRE1.3 (Java Runtime environment) in order to install and run the User Agent software.