Here at Liquidstate HQ, we seem to get more than our fair share of silent and nuisance calls.  We've already signed up for the Telephone Preference Service, but that's only applicable for calls originating from within the UK.  So, after a bout of insomnia, I decided to take matters into my own hands.

Update: I've fixed a cut and paste error with the OBI110 configuration after feedback from Steve in the comments. If you've been struggling to get this working, then hopefully this helps!

Enter the OBi110, a Voice Server Bridge and Telephone Adapter that can effectively join your existing analogue Plain Old Telephone Service (POTS) with a modern Voice-Over-IP (VOIP) solution.  From there, with the help of FreePBX/Asterisk, you can gain complete control of both incoming and outgoing calls.

This post will document my initial configuration to use the OBi110 with FreePBX running on a Raspberry Pi to filter incoming calls based on Caller ID (as well as the time of day).  The OBi110 and FreePBX are both capable of soooo much more, but we'll leave that for a future post!

NOTE!  This is my initial configuration - it's not perfect yet and will no doubt change over time as I learn more about the OBi110 and FreePBX.

Call Workflow

When someone calls us and we are able to determine their number via Caller ID, we direct the call through to the analogue telephone attached to the OBi110.  If we cannot determine a number, the caller is asked to enter their phone number.  Assuming they do, this will then be forwarded through to the analogue phone (with the caller ID set to the number the caller has provided).

Additionally, if someone calls us out of hours (23:00 - 07:30), then we ask them if they wish to continue the call then to press 1.  If they do so, then the above call flow based on Caller ID will apply.


You’ll need an OBi110, a Raspberry Pi with case, power supply and a 4GB SD Card.  You'll also need two Ethernet cables and a 4-core telephone cable to connect both devices to your home network (router) and the OBi110 to your phone line.  I sourced my components from Amazon and eBay.

Configure your Raspberry Pi

Download RasPBX from here and install it into your SD Card.  Detailed instructions for writing can be found here.  Copying the image to the memory card could take up to half an hour.

Now, fit the SD Card to the Pi and connect it to your network with an Ethernet cable and power it up.  After a couple of minutes,  “ssh in-to” the Pi (ssh [email protected]).  The root password is raspberry.  At this point, if you have familiarity with Ubuntu or Debian Linux distributions, you should feel pretty comfortable.  Next, configure a static IP address for your Pi; you will do the same for the OBi110 later so they can talk to each other, and you can talk to them.  In this blog post, my Raspberry Pi is configured on and my OBi110 is on

Update to the latest version of Asterisk (and apply OS upgrades) by running:
This could take an hour or so (don’t forget to type “y” when you are asked to continue).

Reboot your Pi to verify it’s IP and connectivity.

Set the correct time on the Raspberry Pi

SSH back into your Raspberry Pi and run the following command to configure the correct timezone for your area and confirm the time and date is correct.

[email protected]:~# dpkg-reconfigure tzdata

Current default time zone: 'Europe/London'
Local time is now:      Sat Nov  8 21:38:28 GMT 2014.
Universal Time is now:  Sat Nov  8 21:38:28 UTC 2014.

Connect the OBi110

Plug in your OBi110 to power and your network/router using an ethernet cable.  Plug your standard analogue phone into the PHONE port on the OBi110 and your POTS line into the LINE port on the OBi1110.  You should be able to make and receive calls as-if the OBi110 wasn’t present.   If this is not true, then do-not proceed.  Check the OBi110 FAQ or the Administration Guide.

Update the OBi110 firmware

To check and apply the latest firmware, dial `***6` on the phone handset connected to the `PHONE` port and follow the voice prompts.  The OBi110 will connect to the Internet, check for the latest firmware and give you the option (1) to install it.  It should only take a minute or two.

Configure the OBi110

Like the Pi, the OBi110 obtains its IP address via DHCP by default.  To find out its current IP address, pick up the phone and dial ***1.  You will hear a pre-recorded message that reads out the current IP address.  Enter the address into your browser:, where the X’s are the OBi110′s IP address.  The default username is "admin" and the password is also “admin”.

NOTE:  As changes are made on each page to the OBi110, they must be saved by pressing the “submit” button on the bottom of each page BEFORE navigating to another page.  Once all the pages have been configured, press the “Reboot” button in the upper right corner to activate the changes.

Static IP Address

Change the following settings to configure a static IP address for your OBi110 device.  Below are the settings that I used, but you should set these appropriately for your home network.  I use Google's public DNS servers for name resolution ( and

System Management:
   Network Settings:
      Internet Settings:
         <strong>Addressing Type:  Static

Time Configuration

By default, the OBi110 is configured to automatically update its time from the Internet, but I had to change the timezone to suit my locale.

System Management:
   Network Settings:
      Time Service Settings:
         LocalTimeZone:  GMT +00:00 (London,Lisbon)

Configure the OBi110 as an FXO Port

We want configure the OBi110 so that any incoming calls are routed to the RasPBX software running on our Raspberry Pi (connected via Voice Service SP2).

Physical Interfaces
   Line Port
      Line Port
         InboundCallRoute:  SP2
         RingDelay:  3500  (delay in ms the Obi 110 will allow the phone to ring before giving up on waiting for Caller ID)
         DialDigitOnTime:  100  (speed up your dialling by reducing the time in ms each digit tone is played for during dialling)
         DialDigitOffTime:  100  (speed up your dialling by reducing the delay in ms between each digit when dialling)
Physical Interfaces
   Line Port
      PSTN Disconnection Detection
         SilienceTimeThreshold:  600  (increase the number of seconds of silence permitted before disconnecting a call)

Now lets configure Voice Service SP2:

Voice Services
   SP2 Service
      SP2 Service
         X-ServProvProfile:  B
         X_InboundCallRoute:  LI
         X_KeepAliveEnable:  checked
      SIP Credentials:
         AuthUserName: OBITRUNK1
         AuthPassword:  TRUNKPW  (change this!)
         URI:  [email protected]  (replace with the IP address of your Raspberry Pi)

Now configure the ITSP Profile that SP2 uses (Profile B):

Service Providers
   ITSP Profile B
            Proxy Server:  (change to the IP of your Raspberry Pi)</pre>
            X_SpoofCallerID:  checked</pre>
            X_AccessList:  (change to the IP of your Raspberry Pi)

Configure the OBi110 to allow RasPBX to "call out" to the telephone

Service Providers
   ITSP Profile A
            Proxy Server:  (change to the IP of your Raspberry Pi)
            X_UseRefer:  checked
            X_AccessList:  (change to the IP of your Raspberry Pi)
Voice Services
   SP1 Service
      SP1 Service
         X_InboundCallRoute:  PH
      SIP Credentials:
         AuthUserName: 01310000000  (your home phone number)
         AuthPassword:  EXTENSIONPW  (change this!)
         URI:  [email protected]  (replace the first part with your home phone number)
      Calling Features
         MaxSessions: 5
         MWIEnable:  checked
         X_VMWIEnable:  checked
         MessageWaiting:  unchecked


Now, go back through each of the pages and ensure that your remembered to submit your changes on each page!

Once you're happy, press the reboot button in the upper right corner to activate the changes.

Configure FreePBX on your Raspberry Pi

Enter the address into your browser: “”, where the X’s are the Raspberry Pi′s IP address and select FreePBX Administration on the resulting web page.  The default username is admin with password admin.

Configure Trunk

      Add SIP Trunk
      General Settings:
         Trunk Name:  OBITRUNK1
         Outbound CallerID:  01310000000  (replace with your home phone number
         CID Options:  Allow Any CID
      Outgoing Settings:
         Trunk Name:  OBITRUNK1
         PEER Details:
            secret=TRUNKPW  (must match what you entered on OBi110 SP2 SIP Credentials)

Configure Outbound Route

   Outbound Routes
      Add Route
      General Settings:
         Route Name:  Outbound
         Route CID:  <blank>;
         Route Password:  <blank>;
         Route Type:  <unchecked>
      Trunk Sequence For Matched Routes:
         0:  OBITRUNK1

Add an extension

      Add Extension
         Device:  Generic SIP Device
         User Extension:  01310000000  (change to your home phone number - must match OBi110 SP1 URL)
         Display Name: Analogue Phone
         CID Num Alias: <blank>
         SIP Alias: <blank>
      Device Options
         secret: EXTENSIONPW (this must match OBi110 SP1 SIP Credentials)

Configure Night Time IVR

This auto attendant shall play a recorded message if someone calls after hours and asks them to press '1' to continue. In Asterisk you need to install Time Conditions module. In the FreePBX Administration control panel, select Admin -> Module Admin. Click the Check Online button, then click on the Time Conditions module and select Install. Next, click the Process button at the top right to do the actual install. (This also might be a good time to update any out-of-date modules you might have).

Now, lets configure the actual IVR in FreePBX:

      IVR General Settings:
         IVR Name</strong>:  prompt
         IVR Description</strong>:  &lt;blank&gt;

      IVR Options (DTMF):
         Announcement:  PressOneToCallThisNumber
         Direct Dial:  Extensions
         Timeout:  10
         Invalid Retries:  0 
         Invalid Recording:  None
         Invalid Destination:  Terminate Call - Hangup
         Timeout Retries:  0
         Timeout Retry Recording:  Default
         Append Announcement on Retry:  unchecked
        Timeout Recording:  None
        Timeout Destination:  Terminate Call - Play SIT Tone (Zapateller)
         Return to IVR after VM:  unchecked
      IVR Entries:
        Ext:  1
        Destination:  Extensions - <01310000000>
         Return:  unchecked


   System Recordings:
      Built-In Recordings:
         Select System Recording:  en/vm-tocallnum
         Name this recording:  PressOneToCallThisNumber


      Add Announcement

      General Settings:
         Description:  nightwarning
         Recording:  PressOneToCallThisNumber
         Repeat: disable
         Allow Skip: no
         Return to IVR: yes
         Don't Answer Channel: yes
         Destination after playback:
            IVR: prompt


Time Groups
      Add Time Group

      <>Description: daytime
      <>Time to start:  07:30
      <>Time to finish:  22:00
      <>Week day start:  Monday
      <>Week day finish:  Sunday
      <>Month day start:  1
      <>Month day finish:  31
      <>Month start:  January
      <>Month finish:  December
   Time Conditions
      Add Time Condition

      Time condition name:  daytime
      Time group:  daytime
      Destination if time matches:
         Extensions:  <0131000000>
      Destination if time does not match:
         Announcements:  <nightwarning>

Configure Inbound Route

   Inbound Routes
      Add Route
      General Settings:
         Description:  Inbound
         DID Number:  <blank>
         CallerID Number:  <blank>
         Route CID:  <blank>
         Privacy Manager:  Yes
         Max attempts:  1
         Min Length:  7
      Set Destination:
         Time Conditions:  daytime