IP PBX vs Analogue PABX: What Actually Changes, and What to Check Before You Buy
Your PABX still works, so why replace it? This is the comparison without the sales pitch: what the box in the cupboard actually does, what changes when it becomes an IP PBX, which features are genuinely useful in a UAE office, and the four traps that turn a cheap phone system into an expensive one.
What a PBX actually does
Strip away the acronyms and a PBX does four jobs, and it has done them the same way for forty years.
- It gives every position a number. Extension 101 is reception, 205 is accounts, 310 is the warehouse. Internal calls between them cost nothing because they never leave the building.
- It shares outside lines. Fifty staff do not need fifty phone lines. The PBX queues everyone onto the handful of channels your company actually pays for.
- It decides where calls go. Which phones ring for the main number, what happens at 6 pm, where a call lands when nobody answers, which extensions may dial international.
- It carries the features people notice. Transfer, hold, voicemail, call recording, an auto-attendant that says “press 1 for sales”, hunt groups, call queues.
An IP PBX changes none of those jobs. It changes the wiring, the hardware, and what becomes possible on top.
How an analogue PABX works, and where it runs out
A traditional PABX is a metal box with cards in it. One type of card faces the operator (the outside lines), another faces the building (the extensions). Every desk phone needs its own dedicated pair of copper wires running back to that box, which is why old offices have two cabling systems: one for computers, one for telephones.
It works, it is reliable, and for a ten-person office that never changes, replacing it is not urgent. The limits show up when the business moves:
- Growth means hardware. Adding eight extensions means buying an extension card, if the chassis still has a slot, and if the card is still manufactured.
- Moves mean a cable. Relocating someone to another desk is a job for a technician with a punch-down tool, not a two-minute change in a web interface.
- No mobility. The extension is the physical phone. If the person is at home, in a branch or on site, the extension does not follow them.
- Features cost cards and licences. Voicemail, recording and IVR were often add-on modules, and on discontinued systems they are now hard to source.
- Parts and knowledge are thinning. Many Gulf offices run systems whose spare cards come from the second-hand market and whose engineers have retired.
What an IP PBX adds
An IP PBX is the same switchboard running as software on a small appliance (or a server), with extensions that live on your data network. Everything below follows from that one change.
- One cable per desk. The phone plugs into the same network point as the PC, and the PC plugs into the phone. No second cabling system.
- The extension follows the person. Same number rings the desk phone, the mobile app and the laptop. Staff on site or travelling answer the office number, and outbound calls still show the company number.
- Moves and adds are free. A new joiner is an entry in a web page and a phone that provisions itself when it boots.
- Features are included, not bought as cards. IVR, voicemail-to-email, call recording, queues, ring groups, time conditions, reports.
- Branches join as one system. Dubai, Sharjah and Abu Dhabi share an extension plan and call each other free over the network.
- It integrates. CRM pop-ups, hotel property management systems for wake-up calls and room status, door intercoms, paging, access control.
- Lines are elastic. Adding SIP channels for a busy season is a request to the operator, not a new card and a new cable.
Feature-by-feature comparison
| Analogue / digital PABX | IP PBX | |
|---|---|---|
| Extension wiring | Dedicated telephone pair to every desk | Existing network cable, one per desk |
| Adding 10 extensions | Extension card + cabling, if slots exist | Ten entries in a web page and ten phones |
| Remote and mobile staff | Not supported, or via call forwarding that costs money | Mobile and desktop apps on the same extension |
| Multi-site | Separate systems, calls between them are external | One dial plan across branches, internal calls free |
| Auto-attendant / IVR | Optional module on many systems | Standard |
| Voicemail to email | Rare | Standard |
| Call recording | Add-on hardware | Built in, storage limited by disk or licence |
| Queues and call-centre reports | Usually a different product | Licence on the same box |
| CRM and PMS integration | Serial links where supported at all | API and native connectors |
| Power | PABX powers the phones | PoE switch powers the phones |
| Behaviour in a power cut | Depends on the PABX battery | UPS on PBX + PoE switch keeps everything alive |
| Behaviour in an internet outage | Unaffected, lines are copper | Internal calls fine, external needs a backup trunk or 4G gateway |
| Spare parts in 5 years | Second-hand market on discontinued models | Current products, standard SIP phones from many brands |
SIP versus proprietary: the lock-in question nobody asks in time
This is the single most expensive detail in a phone system, and it rarely appears on a quotation.
SIP (Session Initiation Protocol) is the open standard that IP phone systems use to set up and end calls. If a phone speaks SIP and a PBX speaks SIP, they work together, regardless of brand. That is why a Yealink phone registers happily to a Yeastar, Grandstream, 3CX or Asterisk system, and why you can change one part without replacing the other.
Proprietary protocols are the opposite by design. Some vendors build handsets that only register to their own platform, or “IP phones” that are really digital phones with a network socket. They work well, until the day you want a different PBX, a cheaper handset, or a feature the vendor has decided to charge for. Then every phone in the building is scrap.
| Open SIP ecosystem | Proprietary / single-vendor | |
|---|---|---|
| Phones | Any SIP phone: Yealink, Grandstream, Fanvil, Cisco in SIP mode | Only the vendor’s own handsets |
| Changing the PBX later | Keep the phones, reprovision them | Replace the phones as well |
| Price pressure | Several brands compete for your order | One price list, take it or leave it |
| Second source in an emergency | Any distributor in the UAE | The vendor, at the vendor’s lead time |
| Trunks | Standard SIP trunk from e& or du | Often the vendor’s own SIP service |
| Useful when | Almost always | You are standardised on one vendor group-wide and accept the trade |
Everything IRIX deploys as a default is SIP-first: Yeastar and Grandstream systems with Yealink, Grandstream or Fanvil handsets, all interchangeable. We also supply Cisco where a corporate standard requires it, and we will say plainly which of its models run SIP firmware and which do not.
Five things to check before you sign
- Is the PBX SIP-standard, and are the phones interchangeable? See above. This decides what your next upgrade costs.
- What is licensed, and what is included? Ask for the price with the features you will actually use switched on: recording for X users, queues, the hotel module, the mobile app for everyone. “Base price” quotes are how two suppliers appear to differ by thousands of dirhams.
- Who owns the trunk and the numbers? The SIP trunk should be in your company name with e& or du. If a supplier insists on selling you minutes through their own platform, ask which TDRA licence that runs on.
- What happens when something fails? Where does the configuration backup live, who can restore it, and can you get into the system yourself? Ask for admin credentials in writing at handover. A phone system you cannot log into is a subscription to one supplier.
- Is the building ready? Enough network points, a PoE switch with headroom, a UPS, and a decision about the analogue devices. These three lines missing from a quote are the usual reason a “cheap” system ends up costing more.
Does IP cost more?
Up front, an IP system is usually similar or cheaper than expanding an old PABX, because the expensive part of the legacy world is the cabling and the cards. Over five years it is normally clearly cheaper, for three reasons: no telephone cabling to maintain, moves and adds done in-house, and internal calls between branches that stop appearing on the operator bill.
Where IP can cost more is when someone sells you a per-user subscription, premium handsets for every desk, or a proprietary platform whose accessories carry a brand tax. The full cost breakdown, with UAE prices for a 20-seat and a 50-seat office, is in the IP PBX buying guide.
Moving across without losing a day of calls
- Survey. Count extensions and shared phones, list every analogue device (fax, lift, gate, paging), check network points and the internet connection.
- Run both systems in parallel. The new IP PBX is installed and configured while the old PABX still carries the live numbers.
- Move the analogue devices onto gateways. FXS and FXO gateways connect the fax machine, the room phones and any line that must stay.
- Cut over the trunk. The operator points your existing numbers at the new trunk, usually at a quiet hour. Test inbound, outbound, fax and emergency numbers before leaving.
- Keep the old box for a week. Cheap insurance, and it makes the decision to retire it a calm one.
Thinking about replacing a PABX?
Send the extension count, the analogue devices you must keep, and who your operator is. We will come back within one working day with a sized system, what it costs installed, and an honest note on whether replacing now is worth it at all.
Questions we get asked
What is the purpose of a PABX?
A PABX (private automatic branch exchange) is the switchboard your company owns. It connects internal extensions to each other for free, shares a small number of outside lines between many staff, and applies the rules you set: who can dial international, which phones ring for the main number, where a call goes when nobody answers. Without it, every desk would need its own line from the operator.
What is the difference between IP PBX and EPABX?
EPABX simply means an electronic PABX, the traditional box with analogue or digital extension cards. An IP PBX does the same job but over your data network: extensions are IP phones or apps on a laptop and mobile, and lines arrive as a SIP trunk instead of copper pairs. The difference is not the features on paper, it is that an IP system is software you can extend, while an EPABX is fixed hardware you can only grow by buying cards.
Can I use an IP phone like a normal phone?
Yes. It sits on the desk, has a handset and a keypad, and you dial a number. The difference is invisible to the user: the call travels over the network cable instead of a telephone pair, and one cable carries both the call and the power.
Is VoIP better than a landline for a UAE office?
For a business with more than a handful of staff, yes, on cost per line, features and flexibility. The landline is not going away though: your SIP trunk still comes from e& or du, and in some buildings a legacy line stays for the lift or the alarm. The sensible answer is a modern IP PBX with licensed local trunks, plus a gateway for the few analogue things that have to remain.
Are IP phones still used, or has everything moved to apps?
Both, and in a UAE office the desk phone is far from dead. Reception, hotel rooms, clinics, warehouses, security cabins and any shared position still need a physical phone that anyone can pick up. Staff who travel use the app. Most systems we install are a mix.
Why do some phones only work with one brand of PBX?
Because they speak a proprietary protocol instead of SIP. Some vendors design handsets that register only to their own system so that replacing the PBX means replacing every phone. SIP is the open standard: a SIP phone from one brand registers to a SIP PBX from another. We sell both kinds of hardware, but we recommend SIP-first systems, and we will tell you when a model locks you in.
Do I have to pay per user every month?
Not with the on-premise systems we deploy. Yeastar and Grandstream are a one-off purchase; optional licences exist for specific features (call centre queues, recording capacity, hotel modules), not for each employee. Hosted and cloud PBX services are the ones billed per user per month, forever, which is worth modelling over five years before you sign.
Can I keep my existing phone numbers?
Usually yes, when the line stays with the same operator. The number belongs to e& or du, not to your PBX, so the change is on their side: the trunk is provisioned with your existing numbers pointing at it. Confirm this with the operator before ordering hardware; it is the one step outside our control.
What happens to my old Panasonic or NEC handsets?
The proprietary digital ones cannot register to an IP PBX, so they are retired or kept on a separate legacy card. Plain analogue handsets are different: an FXS gateway keeps them working, which is how hotels move to IP without changing hundreds of room phones in one week.
How long does a replacement take?
For a 20 to 50-seat office: a survey, then configuration in our office, then one day on site for installation and cutover. Larger sites and hotels are phased floor by floor or wing by wing so the building is never without phones.
Written by the IRIX telephony team in Bur Dubai, from systems we install in the UAE every month. Browse IP PBX systems, IP phones, VoIP gateways and PBX modules, all brand new with manufacturer warranty.