If you’re looking for the latest and greatest pure GPL, open source Asterisk® 13 aggregation with a pure GPL, open source graphical user interface, then today’s another lucky day for you. Last week, we introduced the Ubuntu 14 edition of Incredible PBX™ for Asterisk 13, and this week we have the CentOS/Scientific Linux flavor to share. This is an independent aggregation based solely upon GPL code. Unlike the competition, the operating system and cloud repository to support the product also are pure GPL open source code. And the Incredible PBX installers themselves are pure GPL open source code. You are more than welcome (encouraged!) to examine, improve, and share your discoveries.

Incredible PBX for CentOS 6.7 and 7 follows our standard install procedure which means it’s up to you to first create a CentOS 6.7 or 7 platform. If you prefer Scientific Linux or Oracle Linux, feel free to start there. All work equally well as a base platform and are supported by a worldwide group of developers. Once your OS platform is in place, simply run the Incredible PBX installer. After 30-60 minutes of whirring, you’ll end up with an awesome (free) state-of-the-art Asterisk-based VoIP server with the very latest LTS version of Asterisk 13 as well as dozens of turnkey Incredible PBX applications. So enjoy a nice lunch while the Incredible PBX installer works its magic. No user intervention is required during the installation procedure. All text-to-speech (TTS) applications work out of the box. You can add Google’s Speech Recognition to many Incredible PBX applications by following our 5-minute tutorial. And a GPL installation script for free faxing with HylaFax and AvantFax is also included. Be sure to download the latest Incredible Fax installer!

Installing a Base CentOS Operating System

CAUTION: Installing Incredible PBX on the CentOS 7 platform is still a work in progress that is suitable for pioneers only. For production systems, stick with 6.7.

Let’s begin by installing 64-bit CentOS 6.7 or 7 on your favorite hardware or Desktop. Or you may prefer to use a Cloud provider1 that already offers a preconfigured CentOS image. In the latter case, you can skip this section.

For those using a dedicated hardware platform or wishing to install CentOS as a virtual machine, the drill is the same. Start by downloading the 64-bit CentOS 6.7 minimal ISO or the CentOS 7 minimal ISO or . Burn the ISO to a DVD unless you’ll be booting from the ISO on a virtual machine platform such as VirtualBox. On virtual platforms, we recommend at least 1GB RAM and a 20GB dedicated drive. For VirtualBox, here are the settings:

Type: Linux
Version: RedHat 64-bit
RAM: 1024MB
Default Drive Options with 20GB+ space
Create
Settings->System: Enable IO APIC and Disable HW Clock (leave rest alone)
Settings->Audio: Enable
Settings->Network: Enable, Bridged
Settings->Storage: Far right CD icon (choose your ISO)
Start

Boot your server with the ISO, and start the CentOS install. Here are the simplest installation steps:

Choose Language and Click Continue
Click: Install Destination (do not change anything!)
Click: Done
Click: Network & Hostname
Click: ON
Click: Done
Click: Begin Installation
Click: Root Password: password, password, Click Done twice
Wait for Minimal Software Install and Setup to finish
Click: Reboot

Configuring CentOS 6.x or 7 for Incredible PBX Installation

Now log into your server as root and issue the following commands to put the basic pieces in place and to reconfigure your Ethernet port as eth0. Make a note of your IP address so you can log in with SSH.

setenforce 0
yum -y install net-tools nano wget tar
yum -y upgrade --skip-broken
# decipher your server's IP address
ifconfig
# patch grub and ignore errors if your server doesn't use it
sed -i 's|quiet|quiet net.ifnames=0 biosdevdame=0|' /etc/default/grub
grub2-mkconfig -o /boot/grub2/grub.cfg
# for older CentOS/SL 6.7 platforms, perform 3 steps below:
#wget http://incrediblepbx.com/update-kernel-devel
#chmod +x update-kernel-devel
#./update-kernel-devel
reboot

If you’re on a virtual machine platform, now would be a good time to make an export or backup of your CentOS image. The minimal install is about 500MB. Don’t forget to first remove your hardware address (HWADDR) and network UUID from /etc/sysconfig/network-scripts/ifcfg-enp0s3 or whatever file name was assigned to your hardware. The saved image will be bootable with DHCP network support anywhere down the road.

NEWS FLASH: For those wanting to test things out using VirtualBox, a Scientific Linux 7.1 Remix image (2GB) is now available on SourceForge. It gets you to right here in the install process.


Installing Incredible PBX for CentOS 6.7 or 7

Adding Incredible PBX to a running CentOS 6.7 or 7 server is a walk in the park. To restate the obvious, your server needs a reliable Internet connection to proceed. Be sure to use SSH (or Putty on a Windows machine) to begin because the installer locks the firewall down to your local network and the IP address of the machine from which you perform the install. Log into your new server as root at the IP address you deciphered in the ifconfig step in the CentOS installation procedure above.

WARNING: If you’re using a 512MB droplet at Digital Ocean, be advised that their setups do NOT include a swap file. This may cause serious problems when you run out of RAM. Uncomment ./create-swapfile-DO line below to create a 1GB swap file which will be activated whenever you exceed 90% RAM usage on Digital Ocean.

Now let’s begin the Incredible PBX install.

NOTE: To more clearly identify packaging as we move forward, there has been a change in the Incredible PBX naming and numbering scheme. Henceforth, the file name and version reflects the Asterisk version, the GUI version, the Incredible PBX release number, and the OS platform. For example, incrediblepbx13-12.0-centos tells you the product includes Asterisk 13, the version 12 GUI, .0 release number, and the CentOS platform.

cd /root
wget http://incrediblepbx.com/incrediblepbx13-12.2-centos.tar.gz
tar zxvf incrediblepbx*
#./create-swapfile-DO
./IncrediblePBX*

Once you have agreed to the license agreement and terms of use, press Enter and go have a long cup of coffee. The Incredible PBX installer runs unattended so find something to do for the next 30-60 minutes unless you just like watching code compile. When the installation is complete, reboot your server and log back in as root. You should be greeted by something like this showing the status of the major apps as well as your free RAM and DISK space:

Perform the following steps:

Make your root password very secure: passwd
Create admin password for GUI access: /root/admin-pw-change
Set your correct time zone: /root/timezone-setup
Create admin password for web apps: htpasswd /etc/pbx/wwwpasswd admin
Make a copy of your Knock codes: cat /root/knock.FAQ
Decipher IP address and other info about your server: status

Incredible PBX includes an automatic update utility which downloads important updates whenever you log into your server as root. We recommend you log in once a week to keep your server current.

You can access the Incredible PBX GUI using your favorite web browser to configure your server. Just enter the IP address shown in the status display.

Choose Incredible GUI Administration from the Admin menu of the Kennonsoft GUI (shown above) by clicking on User to switch. The default username is admin and the password is what you set when the install completed. Now edit extension 701 so you can figure out (or change) the randomized passwords that were set up for your 701 extension and voicemail account: Applications -> Extensions -> 701. If you’re behind a hardware-based firewall, verify the NAT setting: YES.

Setting Up a Soft Phone to Use with Incredible PBX

Now you’re ready to set up a telephone so that you can play with Incredible PBX. We recommend YateClient which is free. Download it from here. Run YateClient once you’ve installed it and enter the credentials for the 701 extension on Incredible PBX. You’ll need the IP address of your server plus your extension
701 password. Choose Settings -> Accounts and click the New button. Fill in the blanks using the IP address of your server, 701 for your account name, and whatever password you created for the extension. Click OK.

Once you are registered to extension 701, close the Account window. Then click on YATE’s Telephony Tab and place some test calls to the numerous apps that are preconfigured on Incredible PBX. Dial a few of these to get started:


DEMO - Allison's IVR Demo
947 - Weather by ZIP Code
951 - Yahoo News
*61 - Time of Day
*68 - Wakeup Call
TODAY - Today in History

Now you’re ready to connect to the telephones in the rest of the world. If you live in the U.S., the easiest way (at least for now) is to set up a free Google Voice account. Google has threatened to shut this down but as this is written, it still works. We will have an update for OAUTH authentication support soon. The safer long-term solution is to choose several SIP providers and set up redundant trunks for your incoming and outbound calls. The PIAF Forum includes dozens of recommendations to get you started.

Configuring Google Voice

If you want to use Google Voice, you’ll need a dedicated Google Voice account to support Incredible PBX. If you want to use the inbound fax capabilities of Incredible Fax, then you’ll need an additional Google Voice line that can be routed to the FAX custom destination using the GUI. The more obscure the username (with some embedded numbers), the better off you will be. This will keep folks from bombarding you with unsolicited Gtalk chat messages, and who knows what nefarious scheme will be discovered using Google messaging six months from now. So keep this account a secret!

We’ve tested this extensively using an existing Gmail account, and inbound calling is just not reliable. The reason seems to be that Google always chooses Gmail chat as the inbound call destination if there are multiple registrations from the same IP address. So, be reasonable. Do it our way! Set up a dedicated Gmail and Google Voice account, and use it exclusively with Incredible PBX. It’s free at least through 2013. Google Voice no longer is by invitation only so, if you’re in the U.S. or have a friend that is, head over to the Google Voice site and register.

You must choose a telephone number (aka DID) for your new account, or Google Voice calling will not work… in either direction. Google used to permit outbound Gtalk calls using a fake CallerID, but that obviously led to abuse so it’s over! You also have to tie your Google Voice account to at least one working phone number as part of the initial setup process. Your cellphone number will work just fine. Don’t skip this step either. Just enter the provided 2-digit confirmation code when you tell Google to place the test call to the phone number you entered. Once the number is registered, you can disable it if you’d like in Settings, Voice Setting, Phones. But…

IMPORTANT: Be sure to enable the Google Chat option as one of your phone destinations in Settings, Voice Setting, Phones. That’s the destination we need for The Incredible PBX to work its magic! Otherwise, all inbound and outbound calls will fail. If you don’t see this option, you may need to call up Gmail and enable Google Chat there first. Then go back to the Google Voice Settings.

While you’re still in Google Voice Settings, click on the Calls tab. Make sure your settings match these:

  • Call ScreeningOFF
  • Call PresentationOFF
  • Caller ID (In)Display Caller’s Number
  • Caller ID (Out)Don’t Change Anything
  • Do Not DisturbOFF
  • Call Options (Enable Recording)OFF
  • Global Spam FilteringON

Click Save Changes once you adjust your settings. Under the Voicemail tab, plug in your email address so you get notified of new voicemails. Down the road, receipt of a Google Voice voicemail will be a big hint that something has come unglued on your PBX.

UPDATE: Google has improved things… again. You may not see the options documented above at all. Instead, you may be presented with the new Google Voice interface which does not include the Google Chat option. But fear not. At least for now there’s still a way to get there. After you have set up your new phone number, click on (1) Settings -> Phone Numbers and then click (2) Transfer (as shown below). That returned the old UI. Make sure the Google Chat option is selected and disable forwarding calls to default phone number.



One final word of caution is in order regardless of your choice of providers: Do NOT use special characters in any provider passwords, or nothing will work!

Now you’re ready to set up your Google Voice trunk in the GUI. After logging in with your browser, click the Connectivity tab and choose Google Voice/Motif. To Add a new Google Voice account, just fill out the form. Do NOT check the third box or incoming calls will never ring!

IMPORTANT LAST STEP: Google Voice will not work unless you restart Asterisk from the Linux command line at this juncture. Using SSH, log into your server as root and issue the following command: amportal restart.

If you have trouble getting Google Voice to work (especially if you have previously used your Google Voice account from a different IP address), try this Google Voice Reset Procedure. It usually fixes connectivity problems. If it still doesn’t work, enable Less Secure Apps using this Google tool.

Troubleshooting Audio and DTMF Problems

You can avoid one-way audio on calls and touchtones that don’t work with these simple settings in the GUI: Settings -> Asterisk SIP Settings. Just plug in your public IP address and your private IP subnet. Then set ULAW as the only Audio Codec.

A Few Words about the Incredible PBX Security Model for CentOS

Incredible PBX for CentOS joins our previous Ubuntu build as our most secure turnkey PBX implementation. As configured, it is protected by both Fail2Ban and a hardened configuration of the IPtables Linux firewall. The latest release also includes Port Knocker for simple, secure access from any remote computer or smartphone. You can get up to speed on how the technology works by reading the Nerd Vittles tutorial. Your Port Knocker credentials are stored in /root/knock.FAQ together with activation instructions for your server and mobile devices. The NeoRouter VPN client also is included for rock-solid, secure connectivity to remote users. Read our previous tutorial for setup instructions. As configured, nobody can access your PBX without your credentials AND an IP address that is either on your private network or that matches the IP address of your server or the PC from which you installed Incredible PBX. You can whitelist additional IP addresses by running the command-line utility /root/add-ip. You can remove whitelisted IP addresses by running /root/del-acct. Incredible PBX is preconfigured to let you connect to many of the leading SIP hosting providers without additional firewall tweaking. We always recommend you also add an extra layer of protection by running your server behind a hardware-based firewall with no Internet port exposure, but that’s your call. And it’s your phone bill. 😉

The IPtables firewall is a complex piece of software. If you need assistance with configuring it, visit the PIAF Forum for some friendly assistance.

Incredible Backup and Restore

We’re pleased to introduce our latest backup and restore utilities for Incredible PBX. Running /root/incrediblebackup will create a backup image of your server in /tmp. This backup image then can be copied to any other medium desired for storage. To restore it to another Incredible PBX server, simply copy the image to a server running Asterisk 13 and the same version of the Incredible PBX GUI. Then run /root/incrediblerestore. Doesn’t get much simpler than that.

Incredible PBX Automatic Update Utility

Every time you log into your server as root, Incredible PBX will ping the IncrediblePBX.com web site to determine whether one or more updates are available to bring your server up to current specs. We recommend you log in at least once a week just in case some new security vulnerability should come along.

In the meantime, we encourage you to sign up for an account on the PIAF Forum and join the discussion. In addition to providing first-class, free support, we think you’ll enjoy the camaraderie.

Originally published: Monday, July 13, 2015


Support Issues. With any application as sophisticated as this one, you’re bound to have questions. Blog comments are a terrible place to handle support issues although we welcome general comments about our articles and software. If you have particular support issues, we encourage you to get actively involved in the PBX in a Flash Forums. It’s the best Asterisk tech support site in the business, and it’s all free! Please have a look and post your support questions there. Unlike some forums, ours is extremely friendly and is supported by literally hundreds of Asterisk gurus and thousands of users just like you. You won’t have to wait long for an answer to your question.





Need help with Asterisk? Visit the PBX in a Flash Forum.


 

Special Thanks to Our Generous Sponsors

FULL DISCLOSURE: 3CX, RentPBX, Amazon, Vitelity, DigitalOcean, Vultr and others provide financial support to Nerd Vittles and our open source projects through advertising or referral revenue. We’ve chosen these providers not the other way around. Our decisions were based upon their corporate reputation and the quality of their offerings and their pricing. Our technology recommendations are reached independently of financial considerations except in situations in which comparable products at comparable pricing are available from multiple sources. In this limited case, we support our sponsors because our sponsors support us.

Awesome Vitelity Special. Vitelity has generously offered a terrific discount for Nerd Vittles readers. You now can get an almost half-price DID from our special Vitelity sign-up link. If you’re seeking the best flexibility in choosing an area code and phone number plus the lowest entry level pricing plus high quality calls, then Vitelity is the hands-down winner. Vitelity provides Tier A DID inbound service in over 3,000 rate centers throughout the US and Canada. When you use our special link to sign up, Nerd Vittles gets a few shekels down the road to support our open source development efforts while you get an incredible signup deal as well. The going rate for Vitelity’s DID service is $7.95 a month which includes up to 4,000 incoming minutes on two simultaneous channels with terminations priced at 1.45¢ per minute. Not any more! For our users, here’s a deal you can’t (and shouldn’t) refuse! Sign up now, and you can purchase a Tier A DID with unlimited incoming calls and four simultaneous channels for just $3.99 a month. To check availability of local numbers and tiers of service from Vitelity, click here. NOTE: You can only use the Nerd Vittles sign-up link to order your DIDs, or you won’t get the special pricing! Vitelity’s rate is just 1.44¢ per minute for outbound calls in the U.S. There is a $35 prepay when you sign up. This covers future usage. Any balance is refundable if you decide to discontinue service with Vitelity.


​​3CX is a software PBX that’s easy to install & manage. It includes integrated softphones, WebRTC conferencing and essential add-ons out of the box, at no additional cost. Try the free edition at www.3cx.com. Better yet, download the PIAF5 ISO powered by 3CX. Free version includes support for 8 simultaneous calls with a SIP trunk.

  • Run on Premise or in the Cloud, on Windows and now on Linux
  • Softphones for iOS, Android, Win & Mac
  • Easy install, backup & restore, version upgrades
  • Automatically configures IP Phones, SIP Trunks & Gateways

  • RentPBX, a long-time partner and supporter of PIAF project, is offering generous discounts for Nerd Vittles readers. For all of your Incredible PBX hosting needs, sign up at www.RentPBX.com and use code NOGOTCHAS to get the special pricing. The code will lower the price to $14.99/month, originally $24.99/month. It’s less than 50¢/day.


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    1. Some of our links refer users to Amazon or other service providers when we find their prices are competitive for the recommended products. Nerd Vittles receives a small referral fee from these providers to help cover the costs of our blog. We never recommend particular products solely to generate commissions. However, when pricing is comparable or availability is favorable, we support these providers because they support us. []