Hi Srinivas,
My name is Chris, I think I can help.
So there are a few ways to use these phones directly (IP Dialing). You said you already enabled IP Dialing under the interface, but you also need to turn on Make Call Without Reg and Ans Call Without Reg. These are usually in the Proxy and Registration section. (Sorry I don't have a sample admin to go off of, or I could be a bit more specific)
Once those three settings are turned on go into the subscriber information section for the line you want to use and set the display name and user ID. For example, take the first phone at 192.168.113.3, you could use 3 for the display name or something more descriptive (like office, garage, etc). Display name is what will show up on the other phones when you call them. You also set user ID, and this you would want to set to a number. It can be 3, 5, and 8, or whatever else you want to use. This number basically becomes the ID of that extension. You can leave all the other subscriber info blank.
Once these settings are in place on all the phones you need to setup the dial plan, which is usually located on the bottom of the same config page you've been using.
Dial plans can be a bit complicated looking, but here is a basic one:
(<103:3@192.168.113.3>|<105:5@192.168.113.5>|<108:8@192.168.113.8>)
This line reads like this: When you dial 103, it will call extension (or user ID) 3 at IP address 192.168.113.3. Same goes for 105 and 108. The first number is what you are dialing, and number after the colon is the extension (or user ID) at the IP address for that phone. I used a three digit number only to avoid confusion, you can make the number you dial whatever you want.
Dial plans can be much more complicated, but this is just to give you an idea. If you only use the line above as your dial plan, you will basically only be able to call those three phones. You can add the entries to what is already there, but if these phones are only being used to call each other this is all you really need.
Here is the Cisco page explaining all of the options available for a dial plan, in case you want to customize it further:
http://www.cisco.com/en/US/products/ps10033/products_qanda_item09186a0080a35a44.shtml
Hope this helps, let me know how it goes.
Christopher Ebert
Network Support Engineer - Cisco Small Business Center
