Planning
Almost everyone jumps straight into setting up a PBX — assigning extension numbers, conferences and call queues — and quickly discovers they didn't leave enough room for new devices, or for an unexpected change like adding 150 new staff. Take our word for it: it is much easier to make a few paper notes deciding your number ranges before you start creating devices and queues.
The single most valuable thing you can do before day one is sketch out a numbering plan. Renumbering a live system after the fact is possible, but planning it up front is free.
Your network
The PBX server should have a fixed (static) IP address so it doesn't change in daily operation — everything else finds the PBX at that address. The phones themselves can get dynamic addresses from DHCP without any problem.
Even a small company with only a few staff should seriously consider four-digit numbering — extensions starting at 1000 rather than 100. After setting up and administering many phone systems for many companies, the easiest to live with are always the ones that were planned. For example:
| Range | Used for |
|---|---|
1000–2999 | Desktop phones |
3000–3999 | Conference rooms for different departments |
4000–4999 | Call-centre queues — Sales, different Support levels, Shipping, Finance, etc. |
5000–5499 | Ring groups — where associated staff extensions are gathered |
6000–6199 | Special devices — fax machines, lobby phones, etc. |
A ring group is a set of extensions that ring together. For example, all the admin staff could be in one ring group, so every admin phone rings when someone calls the admin line. An executive's desk phone could be in a ring group with their assistant's phone, so both ring at the same time.
Ranges like these leave space for future expansion. If the company grows, you slot new devices into the right band without collisions or renumbering — most growth is accommodated painlessly.
Numbers & providers
Your PBX is great for keeping staff in touch with each other, but you need an external service so customers can call your staff, and your staff can call customers. These connections are called trunks and are available from many providers. Depending on the provider, a trunk can allow anywhere from 1 to 50 different calls at the same time, using either the SIP or IAX2 protocol to pass calls between your PBX and the outside world.
With a trunk configured, your staff can make outgoing calls to customers and prospects. But a customer calling you needs a phone number to reach you at — this is called a DID (Direct Inward Dial), such as (647) 600-4381.
- New company? Purchase a DID from your VoIP provider and pay a small monthly fee for it.
- Existing numbers? Contact your VoIP provider to have your legacy DIDs ported over. The porting charge varies by provider; afterwards there's a small monthly charge per number.
You can connect as many DIDs as you want to the PBX, and callers to each one can get a different greeting and call handling.
Decide what each DID should do
Once your numbers are on the provider account, decide what happens when a customer calls each one:
- One DID — you'll likely want an auto attendant that answers with your company name and offers choices: "Press 1 for Sales, 2 for Support, 3 for Accounting, 4 for Shipping, or 0 for the receptionist."
- Two or more companies — give each its own DID and auto attendant, so callers hear the right company name.
- A dedicated function line (e.g. Technical Support) — skip the menu and point that DID straight at a call queue or ring group.
Also think through what happens if no-one answers, and what happens outside business hours. See Inbound Routes to review all your options.
Phones & people
Traditionally every staff member had their own desk phone. Today it's just as common for staff to use a softphone in their web browser instead — and VoicerOnePBX fully supports both. In fact, when you create a desk extension we automatically create the matching browser softphone for you.
To keep this simple, create a desk phone as an even extension — say 2000 — and VoicerOnePBX automatically allocates 2001 as its associated browser softphone. So when you plan your numbering, assign user extensions as even numbers and leave the odd one beside each for its browser twin.
With your ranges, numbers and phones decided, you're ready to move on to Installation.