Trouble with VoIP

So I am having a lot of trouble getting a voip system in place. I set up a user with and was able to get a sip proxy. But when I applied that info into x-lite, I just get a 503 error. I looked up the 503 error and read that it was due to the sip server being down, or something like that. If anyone has some time to possibly contact me, and maybe spoon feed me some step by step info, I would appreciate it. Send a pm for contact details.

I need that info too bro it gave me the same error