Asterisk dialplan and extension

Good day people, I am new to asterisk and am running 1.8.5.0. I have installed it and gotten it to run on Ubuntu 11.04, now I have created sip users and added a dialplan, but I cant register any 开发者_如何转开发sip client to test calls or do anything with it.

What am I not doing right. Here is my config sup.config

[demo-alice]
type=friend
host=dynamic
secret=1234 
context=users
deny=0.0.0.0/0
permit=192.168.2.2/255.255.255.0 ;

[demo-bob]
type=friend
host=dynamic
secret=1234 
context=users
deny=0.0.0.0/0
permit=192.168.2.2/255.255.255.0 

and here is my extension

[users]
exten=>6001,1,Dial(SIP/demo-alice,20)
exten=>6002,1,Dial(SIP/demo-bob,20)

I get method not allowed error from my SIP clients.

[6001]

username=6001
secret=1234
context=default
type=friend

exten => 6001,1,Dial(SIP/6001,20)