AT&T Syn248 - Getting 4 ooma lines to work with this

I currently have a traditional Avaya PBX system with 3 phone lines and 4 extensions at my office. AT&T recently started charging way too much for the phone service so I was looking into Ooma and ordered the 1 base unit and 3 linx devices. However I want to retain the features that I have on by Avaya system where on each phone you could see what extension is being used. So for example if my employee wants to transfer a call to me she can do so by holding the call, and then selecting my soft key on the phone and it will transfer to me. Also want to see when a phone is being used.

In doing my research I found the AT&T Syn248 system. This basically has 4 analog phone ports and then one LAN port. I was thinking of plugging in 1 base station telephone line into port 1, and then the remaining three linx devices into the other ports. Then since this system connects to the LAN, all I have to do is plug the phones in and hopefully it should work like I need it to. Does anyone else have any experience with this phone system? Here is the manual of the gateway device: http://cdn-media-att.vtp-media.com/media/p/document2/products/{1CF5A933-11F2-4349-9AE7-5C5FE54C1A07}/SB35010_UM_1.pdf

just to let everyone know so far the AT&T Syn248 system works flawlessly with the Ooma service. I have not tried additional lines but so far the single line has been working wonderfully. If you are looking for a phone system that works with Ooma this looks like it works. It gives line use indicator and on screen transferring of calls which is what I wanted.

I know this is a few years old, but did you have to do anything special with your connections for it?