Your business’ phones might be a Private Branch Exchange (PBX) phone system rather than simple Analog phones. For businesses with a PBX, it’ll be important to narrow down if challenges come from PBX system or Shaw phone lines.

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Identifying PBX phones

If you are not sure whether your business has a PBX phone system, the list below may help you to determine whether this is the case.

Phone Features:

  • You have your own extension
  • On some PBX systems you have to dial 9 before calling an external number
  • There is an auto attendant when calling the main line
  • Your answering service has multiple mailboxes and isn’t provided by Shaw
  • Features such as call waiting and call forward are enabled on your phones but show as disabled through the My Shaw phone features.


  • Find the model number on your phone handset and look it up online. Most results will have descriptions like 'PBX' or 'digital phone' which indicates a PBX system.
  • Analog phones can only have 1-4 lines and require two phone cords if you have 3 or 4 lines (some even require 2 phone cords for 2 lines).
    • Many brands specialize in only one type. Nortel, Mitel, Avaya, Cisco, Toshiba, Samsung and others generally only make PBX systems. Panasonic and AT&T do both Analog and PBX systems. RCA and VTech are rarely PBX. In all cases, try to verify.

    Common scenarios with PBX systems

    Caller reaches the Auto Attendant, but after entering their call handling option the call fails:

    • Calls that get to your own auto attendant mean the call successfully routed through Shaw to your internal phone system. Failures inside your phone system are outside of Shaw’s control. Contact your Interconnect to further troubleshoot your PBX system.

    Phone handsets go dead:

    1. Check for signs of power like lights or displays on the phone. If no sign of power, call interconnect.
    2. Check if you can call from one desk to another or access your PBX’s voicemail. If neither of these work, call interconnect.
    3. If everything seems to work internally, but there’s no ability to get an outside line, contact Shaw technical support.

    Poor sound quality on phone calls:

    1. Check if all handsets have the same issue or only specific handsets.
      • For issues specific to certain handsets, disconnect and reconnect the phone cord. If not fixed, contact your interconnect.
      • If all phones affected, make a test internal call from one handset to another and the internal call should sound crystal clear. If not, contact your interconnect.
    2. If tests work out well, it may still be an internal issue, but we’d recommend first calling Shaw technical support to rule out any issue on our side. We can provide free support to ensure Shaw isn’t the issue, whereas most interconnects will charge, so start with us.

    When you try to use External call transfer (ECT) or three way calling, the call disconnects when flashing over to the other caller:

    • Most PBX phones are programmed for the supervisory disconnect (also known as Disconnect supervision) on a feature by feature basis, and it's best to start with programming this into your PBX just for managing ECT. However, for some PBX models/brands, this can't be adjusted on the PBX.
    • If the ECT cannot be managed through your PBX phones you can contact Shaw Business Technical Support and we can make an adjustment to our lines that may resolve this issue. This can however, can cause delays in line availability and can negatively affect busy offices and generally whenever possible best managed through the PBX.

    Obtaining PBX system support

    Companies that support PBX systems are commonly referred to as Interconnects. Shaw cannot help with PBX equipment or the wiring that connects this PBX equipment.

    Usually someone in your business will know who the interconnect for your phones would be. If nobody remembers, look on the back or bottom of the phones, or check on the main PBX box in the back of the business. Most interconnects will tape their business card onto the equipment for easy reference. If you don’t have a business card, ask the interconnect to do this with all the equipment the next time they visit.

    If you don’t already have a support person you deal with, lookup online with a search term like “Calgary Nortel Interconnect” replacing for your city and the brand name of your phone system. This should give many search results for local companies that can help with your system.

    Wiring direct to Shaw phone terminal

    Never plug a PBX phone into the Shaw phone terminal. The phone terminal has analog line connections but PBX phones are a digital system with their own unique wiring. Because of this difference, trying to plug the PBX phone handset direct into the phone terminal could damage either your phone, the Shaw phone terminal or both.

    Any separate equipment could be tested direct to the phone terminal. Fax machines or any basic analog phone that’s not part of your PBX phone system are good devices to test with. For more info on trying this, see How to connect a phone directly to the phone terminal.