Can I use an offsite ATA such as a Grandstream ATA? If so how do I set it up? Also, I got the FreePBX software to connect to my Sip provider (Vitelity). I added a trunk. Where and how do incoming and outgoing routes come in play?
Did you read the wiki yet? , most answers there.
You can use an ATA offsite.
You need at least one incomming and outgoing route. Have you set them up yet? The wiki has a lot of info on this.
You will add an ATA as a regular SIP endpoint in Applications -> Extensions in GUI. Having created a trunk, you can add it (and other trunks) at the bottom of the outbound routes config, in the ‘trunk sequence’ section.
I want to setup the ATA onsite for testing since I am very new and green on FreePBX. I setup a trunk, and extension. I setup an incoming route to that extension and even gave it the MAC address of the ATA. I setup an outgoing route to use the trunk. I assume that is all correct. My question is, how to setup the ATA even for onsite use? I set the proxy with the IP address of the FreePBX box. What about user name and password? Where do I program this info in the FreePBX software? Which exact wiki explains all this about ATAs in some detail. I read several things last night. I found nothing about user name and password, etc. Thanks for your help.
Each ATA is different. Have you read the docs on your ATA? What brand and model are you using?
ATA is the same as a phone or any other SIP device. Username is the extension and password is the secret.
MAC address is meaningless to FreePBX as SIP is layer 3. The only time the MAC address is relevant is if you have the endpoint manager setup and a valid DHCP config to send the boot data to phones (options 66 and 150). The MAC address is used to construct the boot file that is named the same as the MAC. No actual communications occurs at layer 2
Use google (it is a well known search engine), try
http://letmegooglethatforyou.com/?q=freepbx+ata+setup
or drop your dime on the commercial EPM.
I got the ATA to connect after talking to a friend that has a working system. I am now having trouble with incoming and outgoing calls. On an imcoming call from my cell phone I get a recording, "The number you dialed in not in service...". I setup a dialplan on the trunk and the outgoing route.
I am using a Grandstream HT704 & a Linksys PAP2. I like to use the EPM, but I don't recall seeing these to ATAs in the list. Again, I am very new to all this.
Here is how google works:-
http://letmegooglethatforyou.com/?q=freepbx+PAP2
or
http://letmegooglethatforyou.com/?q=freepbx+HT704
you can use any words that might narrow your search, but your goal is to understand how any of the many ATA’s out there can be programmed against Asterisk/FreePBX
New or otherwise, reading the wiki a few times will reduce your stress and increase your knowledge on the basics, many people do that and get their questions fully answered 
.
Changing gears here a little. I have read the wiki several times, and it does help. My question now is does the ATA use it’s dialplan, or the dialplan in FreePBX or both. I can’t send or receive calls, but all is connected.
More reading needed, the ata will usually have a dialstring that needs to agree with the Asterisk/FreePBX ones, it is normally best to disable all “vertical codes” in the ata and allow all dialled numbers to start off with, in this case you will need to read the manual pertinent to your particular ATA.
More reading needed, the ata will usually have a dialstring that needs to agree with the Asterisk/FreePBX ones, it is normally best to disable all “vertical codes” in the ata and allow all dialled numbers to start off with, in this case you will need to read the manual pertinent to your particular ATA.
What do you mean by vertical codes?
Google “ata vertical codes”
I guess you still miss the point of google 
The dialplan on the ATA controls what digits are accepted and sent to the PBX, then the PBX dialplan routes those digits. A proper dial plan will eliminate the need to hit # or wait after dialing.
Dial plans on phones and ATA’s don’t affect inbound calls.