Phone System Using VOIP and Bluetooth


Revision as of 08:03, 28 August 2020 by Falz (talk | contribs)
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After porting my land line to Google Voice I decided to add a backup VOIP line. Some co workers recommened Callcentric so I went with it.I already had an Xlink BTTN to allow me to integrate traditional phones to make calls from cellphones utilizing bluetooth.

Devices I'm using:

  • Callcentric Pay per call plan - VOIP line where you only pay for what you use. Small setup fee and monthly charges are based on their current rates. Currently US calls are $0.0198 which works out to $1.19 for an hour.
  • Callcentric Pay per minute DID - Direct Inward Dialing- this is simply a phone number that interfaces with the phone network so I can recieve calls. Small setup fee and $2/ monthly.
  • Grandstream HT502 - Device that talks VOIP to a provider (Callcentric) and outputs an analog dialtone. Supports two lines, currently using one.
  • XLink BTTN - Device that outputs a dialtone and inputs an analog line and up to 3 bluetooth phones


             (Google Voice)
                   | Series of tubes
             [Home Router]
                   | Ethernet
                   | Phone Wiring
                   |              + - [Cell Phone 1]
                   |              |
              [Xlink BTTN] - - - -+ - [Cell Phone 2]
                   |              |
                   |              + - [Cell Phone 3]
                   | Phone Wiring
             [Home Phones]


Google Voice

Since my land line was ported to Google Voice it is still used to receive many calls. Google Voice is then aware of three phones- two cell phones and the Callcentric DID. Google voice is setup to forward to one, two, or all three of these phones depending on which group the caller is from. If they're not in my contact list they go straight to voicemail and Google Voice will attempt to transcribe it.


Fairly straightforward, you need a DID to receive calls and to configure your HT502. They have Grandstream specific instructions that work perfectly. The gotcha seems to be that you always need to dial using 10 digits, even if local. Notes on this under HT502.

Xlink BTTN

Nothing special here. Long press one of its three top buttons to pair with your phone. Works perfectly with my HTC Evo Shift running Cyanogen 7.x. The wife's LG Optimus S usually works but sometimes doesn't automatically pair. Disabling/re-enabling bluetooth on the phone fixes.


This page addresses 7 digit dialing and how to configure it. They claim that it doesn't work properly with Grandstream. However, this forum thread and the User Manual (PDF) have instructions on how to do it.

I've placed this under the FXS dial plan settings. 608 is my area code:


The pipe symbol (|) are separators. Broken down this appears to mean:

  • [49]11 - allow you to dial 411 or 911 normally
  • <=1608>[2-9]xxxxxx - prepend 1608 when the number starts with 2 through 9 and has six more digits
  • 1[2-9]xxxxxxxxx - Numbers starting with 1 then 2 through 9 and eight more digits dial normally
  • 011[2-9]xx. - Numbers starting with 011 then 2 through 9 and any further length dial normally. This is for international calls.
  • *x+ - I believe this is to allow you to dial things starting with an asterisk to dial voicemail, block call waiting, etc.

Did some testing and it seems to work just fine.