Moving from PSTN trunk to SIP trunk

[vbman213]

Greetings,

My business has a Inter-Tel 5200. All of our endpoints are digital. We are looking at moving from Earthlink (our pstn upstream tone provider) to a VoIP solution...this is a cost-cutting move. I'm not a hardened Inter-Tel administrator (frankly the product scares me). I can do Asterisk/FreePBX but this Inter-Tel box is not friendly at all...I actively avoid looking at it or touching it.

My thought was to get a multiple port ATA like the Obihai obi504vs (4 FXS ports), port the numbers over to a VoIP provider and then plug the Obihai into the 5200...I can't see any reason why this wouldn't work and would allow me to incrementally move over to VoIP (a few lines at a time).

My second thought was getting the Inter-Tel to speak SIP trunk natively. What hardware/license are required for this?

[acejavelin]

You would need SIP trunk licenses to use native SIP trunks, and depending on your router or carrier, you may also need a session border controller of some kind (Mitel Border Gateway is recommended).

There should be no issues using a SIP to analog gateway, although depending on the quality of the gateway there are sometimes issues with things like positive disconnect. AudioCodes, Adtran, Grandstream, Multitech, and other quality devices should work fine as long as your carrier supports them or is standard enough it doesn't matter.

[johnp]

Is this private provided sip or just through the internet? I know people want to save money, but sometimes it ends up backfiring.

[vbman213]

An excellent point. I've already done the math and it will save us an enormous amount of money. I am looking at VoIP.ms

We are a small private school with four phone lines (maybe five) coming into our PBX. Earthlink charges $35 per unlimited local business line and $20 per basic business line. 1 of our lines if unlimited and the other four are basic ($115/month just in maintaining the lines). Add onto that the cost of 100 minutes of calling and you are looking at a bill of about $140/month.

The same service through VoIP.ms would cost around $15/month.

[DND ON]

Hopefully you have reliable lines for 911, fax, alarms, etc.