Setting up my first voip extension

I have installed asteriskNow 1.6 with GUI. When i try to setup a new user from the GUI I get an error asking me to setup a dial plan first. I am new to telephony and I do not understand why I need a dial plan first since i intend to use this in an internal network without dialing to any public phone system like POTS or VOIP gateway. How can I setup a dummy dial plan to enable me to setup user?

I’d suggest using the AsteriskNow forum. I think it uses dialplan differently from Asterisk itself. I believe it uses it in a sense closer to that used on SIP phones, i.e. a pattern which specifies the valid lengths of numbers. You will, presumably, need a “dialplan” that specifies that the only numbers are the fixed length you use for your extensions.

Also note that the current version of AsteriskNow is, at least 1.7.x, and there are no supported 1.6.x versions of Asterisk, so either way, version 1.6 is not suitable for a new install.

If your system really is as simple as you suggest, directly coding the Asterisk configuration is going to be easier to support.