1) you should post a new thread for support on your issue in the "support" board, unless you honestly think this has something to do with GoAutoDial and not Vicidial itself.
2)
when you post, please post your entire configuration including (but not limited to) your installation method and vicidial version with build.
this IS a requirement for posting along with reading the stickies (at the top of each forum) and the manager's manual (available on EFLO.net, both free and paid versions)
You should also post: Asterisk version, telephony hardware (model number is helpful here), cluster information if you have one, and whether any other software is installed in the box. If your installation method is "from scratch" you must post your operating system and should also post the .iso version from which you installed your original operating system.
Similar to This:
Vicibox X.X from .iso | Vicidial X.X.X Build XXXX | Asterisk X.X.X | Single Server | No Digium/Sangoma Hardware | No Extra Software After Installation
3) Your question regarding the best way to support 30 callers is a completely sep question, should be posted sep in support as well. And when you ask: be sure to mention what is available to you at that location as far as Internet speed and T1 Voice connections. (and WHERE you are because some of this equipment is location specific!)