Getting Started - How Low (price) Can I Go?

Hello Asterisk Pros,

I am new to Asterisk so my questions may be low level judging by some of the posts I’ve read here.

I am a small business owner with multiple on-man-band businesses. I am looking for the lowest cost solution that will get me this:

  • 3 individual inbound phone numbers (1 per business) to start.
  • Individual voice greeting per phone number (business).
  • Ability to expand the system to perhaps 10 inbound phone numbers (separate greetings also).
  • All cloud based - no on premisses equipment.
  • All business/phone numbers available/accessible via a iPhone (SIP?).
  • SMS per number would be great, but not entirely necessary.

I would like to self host this if that keeps the costs down, preferable on Linode ( because I already use them for our web hosting.
Use FreePBX for the UI.

Does this configuration and requirements make sense?
Any comments are appreciated.


Twilio is good VOIP provider for DID numbers as well for SIP TRUNK

This is totally free you can configure it on FreePBX using IVR module and on plain Asterisk using any of this app

Background(), Read,Playback()

As far as you have enough resources and bandwidth on your system this wont be an issue

I have installed more than 200 Asterisk Systems on the cloud, some of them on Amazon, Vultr, Digital Ocean, I prefer Vultr if is for FreePBX as they allow you to load the ISO from FreePBX others provider will require scratch installation in this last case it is better Centos 7

Short Answer yes

Again Twilio has a great API for SMS but this will require manual coding , FreePBX also support sms using SIPStation

Hello ambiorixg12,

Thank you for your reply - Great stuff. After some quick reading at the Twillo and Vultr sites I have a few follow on questions if you don’t mind:

  • Do you think the Vultr cloud compute (VC2) instance with 25GB SSD, 1 CPU 1024 MB @ $5 per month would suffice for 2-3 phone numbers and light inbound traffic and FreePBX?

  • Are Twillo and SIPstation the same thing?

  • I would prefer to use Debian or Ubuntu since I am more familiar with them. Will that be a problem?

  • Is there a particular app I will need for the iPhone to receive inbound and make outbound calls with these new numbers?

Thank you,

The critical parameter for Asterisk is CPU scheduling latency, and that is a parameter that is not generally published and may not be managed.

Ideally, for VoIP, you want a real CPU to be allocated to the virtual CPU within about 2ms, although, 20ms may be tolerable.

I know you want to safe but don’t sacrifice the quality and stability of your system.Based on my personal expirience, you should go at least with the 10 USD plan if is no more than 5 phones.

They are provider similar services but Twilio is more for developers due to the rich API they provide

FreePBX provide its own distro, and vultr allows you to load that iSO filce on your servces to do the install, that is the attractive of this VPS provider

Yes a SIP client

You’ll need a SIP client to make calls and a SIP server to receive them. Both may be the same app.

Note that a common problem reported with using mobile phones as SIP servers, is that the OS may shut them down for inactivity…

Also note that WiFi and VoIP don’t mix well, although there are some WiFi enhancements (WMM) that try to prioritise VoIP traffic.

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Thanks for the infos. I am starting up the FreePBX ISO install (on Vultr $10 plan as suggested) and it is asking for Asterisk 13 (recommended) or Asterisk 15. Any suggestions on which I should use?

I also need to pick SIPstation or Twillo. Still not sure which way to go here. Any additional recommendations would be helpful.


I have gave you a lot information, is time also you do some reading or hirer some specialist for a consultancy service. Which I dont think is going to be an option for you as you want to save every single penny

Asterisk 15 is no longer receiving bug-fixes; it’s a standard release [1]. Asterisk 13 will continue to receive bug-fixes until the Fall of 2020.

Your choice and use of SIPStation, because it’s a Sangoma product, directly benefits Asterisk; it puts money in the company’s coffers, which, among other things, gets spent on Asterisk development. Using Twilio in no way benefits Asterisk.

[1] -


We ended up using Twilio instead of SIPstation because SIPStation required a minimum of 1 trunk at $25 per month plus the $1 each or whatever for the individual DIDs. Twilio does not have the trunk fee for elastic SIP trunking. The DID costs look to be about the same as do the per minute cost.

Our setup is described in this thread:

We did stay with Vultr on their $10 plan to start and so far with 3 DIDs and our initial call volume it is performing very well.

Our DIDs are SMS enabled and we struggled with that. We were trying to get the SMS messages to the PBX and then to a extension or user. Maybe we did this wrong, maybe we needed a commercial module. In any case, we decided that we didn’t really need to send text messages right now from the main business DIDs. The only reason we would probably ever receive a SMS to the main DIDs was for new customers. So to accommodate this we setup a Twilio Flow that handles this nicely. Any incoming SMS messages are automatically responded to with a message saying that we do not accept SMS on the main business numbers and included a link to call instead. This way people are not wondering if their message was ignored on not delivered.

You can create a simple php script and setup webhook in Twillio, that way whenever sms received you can handle it in the script either send it to email, or setup twilio sms sending api and forward to concern person. Sms can be handled by scripting like http website.