Frequently Asked Questions - Most common issues


The installation, configuration and exploitation process is too hard.

This is a specialized piece of software and we are always prioritizing state-of-the-art features over making it easier for unexperienced users to deal with it. Anyway, if you got here it means that you are too, for now, looking at future network technologies and should be familiar with the concepts and specs. If you are not, we recommend that you first attend a few tutorials on IMS, Linux administration and C/Java programming; or you could hire somebody (from our community for example) to do the job for you.

It might be that in the future the networks would be so distributed that having IMS cores would be a commodity. But for now, they are not and we can not justify the resources spent on building nice GUIs when there are so many more important open issues.

That is not to say that we would reject you if you would like to invest your resources in making the Open IMS Core more user-friendly. We will always welcome anybody willing to contribute towards making the project better.

I can't find the answer here and I think that I have discovered a bug or something wrong. What to do next?

Most importantly: DO NOT FILL A BUG REPORT IMMEDIATELY!
Second most importantly: DO NOT EVEN THINK ABOUT POSTING SUPPORT REQUESTS IN THE ISSUE TRACKER! The request will be closed. Use the issue tracker only for outstanding bugs that have been discussed and accepted. Think that you might have just mis configured something and you will get your answer quicker and easier by asking on the appropriate mailing-lists.

When in trouble, you should, in this order:
1. Always read the FAQ. There is big probability that you did something wrong and the answer might be just there.
2. Search the Mailing List archives.
3. Use the documentation if possible.
4. Ask on the mailing list.
5. If the community acknowledges the bug/feature-request, post a detailed issue in the Support section.
6. If you found an answer please contribute it back so that others might find it easier. This is an Open Source project and you can only benefit the most when you contribute.

It might take a while until you get an answer as our resources are not unlimited. When you feel that it takes too long, post a reminder. We don't mind you being pushy if you do understand the Open Source model. But we do mind if you don't and you think that we MUST provide you with a satisfying answer.

It might also be that the answer won't satisfy you. In any case, you are most welcomed to contributed in any way that you see fit to the project - code development, website editing, resources, etc.

The CSCFs print a LOT of things. Are these errors?

The target of the whole project is experimental. As such, we love logging because we want to know what happens. The CSCFs might print a lot of those. You can, of course, at any time change the logging level from the configuration file (the debug parameter).

Unless you can tell that there is a bad behavior, don't bother reporting them as errors. On new features we like to print a lot of information colored like crazy even if they are not errors. It helps us notice if the new code functions correctly and also it makes you aware that there is something new ;-). In a few weeks/months these logs would no longer show as they will be demoted to lower importance.

The most important thing to remember is that they should all be prefixed based on the importance, like DBG, INFO, ERR, etc and this prefix overrides the actual colors and log levels.

I have reconfigured the Open IMS Core with a different domain, yet I still see some REGISTER request forwarded to old S-CSCFs.

Are you sure that you have changed all the configuration files? Grep for the old domain name.

Have you changed the s_cscf table in the icscf database? It contains the list of all your S-CSCFs.

Check the imsu table in the hss_db database. It might be that you have IMS Subscriptions that were left as registered in the old S-CSCFs and now the HSS/I-CSCF are trying to redirect you there. Clear the values in there.

I get a "403 Forbidden - HSS returned no authentication vectors". What is wrong?

You have probably forgot to add privileges for the user, that you are trying to register with, to perform authentication with the algorithm of your choice. In most cases you switched the authentication method in the S-CSCF but you did not allow the user to use anything else than AKAv1-MD5.

This error might also indicate that you are trying to use an authentication scheme not supported by the HSS in use. Please check that the authentication scheme is supported.