I have a 900 with a PRI. Can I use a secondary internet-Fios- as a secondary SIP. I can have the PRI fail over to another DID i just ned to know if it's doable in the 900. I am assuming I would have to use outbound 8.

Yes - get a SIP card and SIP trunks.

Program incoming calls identically and when the PRI fails the carrier will forward calls to whatever DID you use and calls will be handled the same.

If you want to insure calls go out on specific trunks you will need to put them in their own line group.

Doesn't the 900 already come SIP ready out of the box?

Jatilano..you are correct the IP900 is SIP ready out of the box.

So in the end the PRI failed anyway- the 900 was set up for a PRI. It had 5 UIP trunks under CO Lines and the site had 4 offices and is practically a call center so that would not work. We bought 900$ worth of UIPs 2 packs of 8 so they have 23 which works for them (we process these calls through the sites Frontier Fiber-we did not install it just using it). The PRI is bad so I am in the process of engineering a solution using a TPAL SD WAN but that is a new router in front of the customers which he probably will not allow since this is a medical facility.

Still working on it. Hoping to get a second circuit like Spectrum but I believe it would take a torpedo under the street and driveway-maybe they will do it for free?