My company is looking at hosted VOIP providers for our work phones. I've noticed that some of the providers we are looking at say they can work with any SIP client, while others have proprietary clients only they work with. I recall reading various discussions about people using SIP on the N8x0 but never really knew what that was about and didn't have the need, so I kind of skipped by it.

Now looking more closely it seems to be just as confusing as I remember. I've come across a lot of posts talking about setting things up, but the end goal generally seems to be about personal use for free or cheap calls, while I'm more interested in integrating into a business setup.

So does anyone care to explain what i would need to get my N900 to work this way? I've seen mention of a SIP client built directly into the phone, but also seen people mentioning using 3rd party apps like Fring (which I've also noticed mentioned on a couple of hosted VOIP provider websites), any reason to go one way or the other? Assuming I can get everything setup, does this allow me to make calls on my N800 using "data" rather than voice minutes?

Any other useful things to know about using the N900 as a SIP client?

The n8x0, the n900 and the n9 all have an inbuilt SIP client. This means that as long as you have a standards compliments server and an account on that server, you should be able to connect to it using your n900.

Most corporate setups usually use VOIP phones only on the internal network.
To connect to the server in this set up you would need to VPN in first.

Thanks. This would be a hosted system using something like Onsip, so no VPN needed I think. I did find the built in SIP client settings (hadn't thought that it would be integrated with the phone app) and I also installed Fring. Should be getting a demo setup with a couple of providers soon, so I'll try both and see which works better (or at all)

So I got a trial account setup at Onsip and have tried getting this to work in both Fring and the native SIP application. Fring doesn't acept the credentials (Onsip has a kind of funky way to enter in everything if you are using Fring, and the only comments are from people on multiple platforms that can't get it to work, so that's not totally surprising). The native SIP client in the phone seems to take the credentials fine and says I've logged in...but I don't know how to actually make it try and use that account? If I try to do a test call it just tells me that I don't have a SIM. Which is true, but I'm connected to Wifi, and my understanding is this should work with data, it just seems like it is trying to use the cell phone client instead. Feel like I'm missing something obvious here.

BTW, this was originally meant to be posted in the N900 section, didn't mean for it to go in General. If a mod would like to move it there (or another forum that is more appropriate) that's fine with me. Sorry for my mistake.

When dialing using the dial pad there should be a 'Call type' drop-down box at the top where you should be able to select your SIP account for the outgoing call. Likewise, when selecting an existing contact from the address book there should be a 'SIP' entry.

Thanks. I'd seen that before, but the first time I'd tried clicking on it there was no drop down box, that might have been before I really had the SIP credentials properly setup though. Working great now.

Anyway to make the SIP the default so I don't have to select it each time?