Both Acrobits Softphone and Groundwire support SMS through Betamax providers (voipcheap, voipbuster, actionvoip, etc.). We support this by reading the domain. If we see a betamax domain, the SMS tab will appear and we will use their API for sending sms. But we have a few notes for betamax users.
1. As mentioned above, we read the betamax providers by domain. But there may be a few domains that we missed. If you have a betamax provider configured and you don't see the SMS tab on the keypad, this is probably the case. Most of the ones we missed will be included in the next update (I'm saying this as of May 16th, 2011) to Acrobits Softphone and Groundwire, but new betamax providers are added all the time, so if you have a betamax provider that doesn't show on the list, let us know and we will add them in the next update.
2. The API we have for betamax providers should work with just about all of them, but there may be a few that don't. Betamax providers pretty much all work the same, but there may be a few that have small differences that make this feature incompatible. If you see the tab for SMS, but are unable to send SMS through that betamax account, open a ticket. We should be able to quickly see if your provider is one of the ones that are incompatible. The only providers we have confirmation do not work with SMS or balance checking are voippro.com, rebvoice.com, megavoip and easyvoip.com, but it may effect other providers as well
3. If you have Groundwire, make sure that your betamax accounts do not have SIMPLE on in the advanced settings. It should not cause an issue, but could make isolating any issues more difficult.
4. With just the basic SIP settings entered (username, password, domain), you will be able to send SMS from your account, but the person will just see some random number for the caller id. There is a way to set this, but you will need to make adjustments in your betamax account online for it to work. I can't give exact directions, it will vary a little between different betamax providers, but the basic process is the same. Log in to your betamax account on the provider's website. Somewhere in the settings, there will be some option to verify numbers to be used for caller id (they generally send some code by SMS to the number you want to use, then you enter that code on the website). Once you verify the number on their website, go to the advanced settings in the SIP Account on Acrobits Softphone or Groundwire and enter the number in the field marked caller id. It must be entered exactly as it appears on the provider's website and you must have the method for caller id set to 'from username'. (This will also set the caller id for VoIP calls).
5. For SMS, the domain must match the providers domain. For SIP VoIP calls, betamax provider domains are generally interchangeable (e.g. a voipcheap account will register and be able to make calls with actionvoip's domain or vice versa). But for SMS to work properly, the domain must be that of the provider you are using.
6. Last, but most important for those with multiple betamax accounts, the API for SMS and balance checking for betamax does not work well for those with multiple betamax accounts configured on the same device. For example, say you entered something incorrectly in your account settings for one of your betamax accounts. After we get a couple of errors checking your account bablance or sending an SMS, your IP would be blocked temporarily, causing issues with the account balance and SMS for all of your betamax accounts. This will usually come up when you enter something incorrectly for one of your betamax account, but may come up other times as well. It usually clears up in an hour or so. We're still experimenting with this, so any users with more information on how betamax handles this, feel free to contact us.