What is VoIP?2019-06-18T03:59:00+00:00

Voice over Internet Protocol, aka VoIP, is the transmission of voice traffic over a data network, e.g. the Internet.

What is a Cloud Hosted PBX?2019-06-18T03:58:26+00:00

It is a software-based phone system, hosted on a virtual server in a data centre, and available anywhere you have a good Internet connection.

What is an auto-attendant?2019-06-18T03:58:34+00:00

An auto-attendant is a voice menu system that answers inbound calls and presents options to the caller.  After listening to the options, the caller then responds by pressing a number corresponding to their choice.

What is a DID?2019-06-18T03:58:41+00:00

A DID is a ‘Direct In-Dial’ number.  You can have a single DID or a range of DIDs depending upon your requirements.

What is a Call Queue?2019-06-18T03:58:51+00:00

A Call Queue is a way to have multiple callers waiting in line to be serviced.  They are used extensively by Inbound Call Centres and increasingly by smaller businesses to manage spikes in inbound calls to a small team of users.  It allows you to keep the caller on hold much longer than if the phone was just ringing, as the caller is listening to music or some other self-promotional message.

How much does it cost to license the mobile/soft clients?2019-06-18T03:59:12+00:00

Nothing, this is included in the solution.

Are there any limits to how many users/extensions can I have?2019-06-18T04:05:19+00:00

As many as you like, within the constraints of your chosen numbering scheme.  E.g. if you utilise a 3-digit numbering scheme, then you can have up to 1000 extensions.

Are there any limits to the number of Ring Groups, Call Queues, Auto Attendants (Digital Receptionists) that I can have on my PBX Blue Cloud Hosted PBX?2019-06-18T03:59:30+00:00

No, you can have as many of these as you like.

Can I send and receive faxes via 3CX?2019-06-18T03:59:37+00:00

Yes, you can receive and send faxes with 3CX.  Faxes are delivered to your Inbox as a PDF attachment. They can be sent using an adaptor plugged into your existing fax machine.

Can I bring my own SIP Trunk?2019-06-18T03:59:43+00:00

No, PBX Blue provides its own SIP Trunk as part of its solution.  Whilst numbers are ported to our system, we will support your old trunk to eliminate any migration glitches.

Can I use my existing VoIP phones?2019-06-18T03:59:53+00:00

Yes, if they are supported by 3CX.  Please refer to https://www.3cx.com/sip-phones/ for a list of supported phones.  Phones with only ‘legacy’ support will be best effort only and may require additional infrastructure to properly support them.

Can I sync my Office 365 address book?2019-06-18T04:00:22+00:00

Yes, each user can sync their Outlook Contacts into 3CX.

Do I have to sign a long-term contract?2019-07-05T02:15:18+00:00

No, there are no lock-in contracts with PBX Blue.

Do you offer a trial?2019-06-24T02:25:55+00:00

Yes, we can setup a free trial for 14 days, so you can evaluate the service and all its functionality.

What about call quality? I’ve been told that VoIP isn’t as clear as a normal phone line.2019-06-24T02:25:59+00:00

This isn’t true. VoIP call quality is largely determined by the quality of your Internet connection and the correct implementation of QoS. QoS (Quality of Service) is where VoIP traffic on your Internet connection is prioritised ahead of other Internet traffic like web browsing, email, YouTube etc. Think of QoS as being like an ambulance using its lights and siren to get through traffic without having to stop.

Can I use the PBX Blue system with an ADSL Internet connection?2019-06-24T05:58:34+00:00

No, unfortunately not. ADSL is not appropriate for business grade VoIP systems. At a minimum, you would need an NBN connection. Better still is MBE, Fibre or Fixed Wireless Internet. Speak to us about these types of connections if you need a new Internet connection. PBX Blue, via its parent company Private Universe, is a partner with AAPT/TPG & Cirrus, and can provide business grade Internet connections.

How long does it take to port my existing numbers?2019-06-24T05:58:57+00:00

This can vary from one week through to a month or longer. A lot of this will depend upon the losing carrier (some of them can be very difficult to deal with) and also whether you need a simple (CAT A) or complex (CAT C) port. During the porting phase we can present the correct caller ID on outbound calls, even before the porting is complete so there is no interruption to your business.

How do I log in and out of a hotdesk phone?2020-05-01T07:30:46+00:00

Logging into a phone

To log into a phone enabled for hotdesking, you will need to know your 3 or 4-digit extension number and your voicemail PIN.

Your voicemail PIN will be in your PBX Blue welcome email sent to you when your extension was first created. If you don’t have this anymore, contact our helpdesk and we will send you a new one.

  1. Check that the phone is currently logged out by seeing if the display shows a number beginning with HD, e.g. HD00001.
    If it shows someone else’s extension number, press the Logout button down the side of the display, or dial *77*5*.

    Logged out hotdesking phone

  2. Dial the following code: *77*your extension number*
    For example, if your extension number is 106, dial *77*106*

    The dial code to log into a hotdesking phone

  3. A voice prompt will ask you for your personal identification number. Type in your voicemail PIN and press #.
  4. The phone will begin a login process. It will be ready to use when all the lights stop flashing and settle.

Logging out of a phone

Remember to log out of a phone when you are finished so that it will be ready to use by the next person.

To log out, press the Logout button down the side of the display, or dial *77*5*.

The logout button on a hotdesking phone

How should I configure my network?2020-04-29T03:35:51+00:00

Networking requirements are different depending on the type of phones you are using to connect to PBX Blue. The requirements below excludes the usual requirements for internet access (e.g. HTTP, HTTPS, DNS, NTP etc.).

Firewall Requirements

The outbound traffic detailed below must be permitted. If you need to limit outbound traffic to a certain destination, you should only do so with the FQDN of your PBX Blue service – we can provide this to you. You should not use the IP address of the service as it can change at any time.

Physical phones provisioned directly to PBX Blue and not through an SBC (including desk phones, conference phones, DECT units, door intercoms etc.):

  • Outbound destination port TCP 443
  • Outbound destination port TCP + UDP 5060
  • Outbound destination port TCP 5061
  • Outbound destination port range UDP 9000-10999

Soft clients (i.e. 3CX web client; 3CX Windows, macOS, iOS and Android apps):

  • Outbound destination port TCP + UDP 5090
  • Outbound destination port 443

Deployments with a Session Border Controller (SBC):

  • Outbound destination port TCP + UDP 5090
  • Outbound destination port 443
  • Phones and SBC should be on the same subnet

The list above assumes that stateful firewalls are in use. If your router or firewall is stateless, you will likely need to create a second set of those rules in the reverse direction.

SIP ALG/helper

SIP ALG (sometimes known as SIP Helper or inspect SIP) must be disabled on your router or firewall. The feature causes more problems than it solves. Please consult the documentation for your router or firewall on how to disable it.

Voice VLAN

You can put physical phones and alike into a dedicated VLAN for voice traffic.

Yealink phones support LLDP for dynamic voice VLAN assignment and it is enabled by default. Consult the documentation for your switch. Alternatively, you can use an OUI-based VLAN assignment feature. At time of writing, the following OUIs are used for Yealink phones:

  • 00:15:65
  • 80:5E:C0

If you have multiple voice VLANs and have an SBC deployed, ensure the voice VLANs are fully routed and do not have any firewall restrictions between them. Alternatively, you can deploy an SBC within each voice VLAN.


Internet connections that have CGNAT enabled, including mobile internet connections, will not register correctly with PBX Blue when physical phones are provisioned directly to it.

Where possible, please ask your internet service provider to disable CGNAT on your service. Alternatively, you can deploy an SBC. Please let us know if this is required and we will help you out.

Soft clients (i.e. 3CX web client; 3CX Windows, macOS, iOS and Android apps) are not affected by CGNAT and will work.

Quality of Service

We recommend that you apply the Quality of Service (QoS) settings detailed below in your network.

Traffic prioritisation

Physical phones provisioned directly to PBX Blue and not through an SBC:

  • DSCP tag 46
  • Destination port TCP + UDP 5060
  • Destination port range UDP 9000-10999

Physical phones provisioned through an SBC:

  • DSCP tag 46
  • Destination port TCP + UDP 5090

Soft clients:

  • Destination port TCP + UDP 5090

Bandwidth reservation

If your internet connection bandwidth is low, we recommend that you apply a bandwidth reservation of 3-4 Mbps for VoIP traffic (depending on the number of endpoints you have). VoIP traffic can be defined by the traffic specified under Traffic prioritisation above. Consult your router or firewall documentation for instructions on how to set this up.

Internet Proxy Servers

Internet proxy servers are not supported. VoIP is not designed to traverse an internet proxy server.

If you have a proxy server in your network and usually put all your internet traffic through it, you will need to make an exception for the FQDN of your PBX Blue service and ensure no authentication is required. This includes soft clients as they use HTTPS for phonebook and extension status information.