What is an on-premise phone system?
An on-premise phone system (premise PBX) keeps the equipment that runs your calls, voicemail, auto attendant and call routing at your own location instead of in the cloud. You own the system, calls between extensions stay on your network, and you connect to the outside world through SIP trunks or phone lines. ATEL Technologies, a San Diego phone system installer since 1985, designs, installs, programs and maintains on-premise and hybrid PBX systems and helps businesses replace or migrate aging systems, including NEC.
When an on-premise phone system makes sense
Lower long-term cost
Pay for the system once instead of a per-user subscription every month, often the lower total cost over 5+ years.
Reliability on site
Internal calls, paging and door phones keep working during an internet outage because call control lives in your building.
Security & control
Your call data and recordings stay on your own network, with fewer outside connections to secure.
Stable headcount
A strong fit for businesses with steady staffing and mostly in-office teams.
Capital purchase
Buy and depreciate the system as an asset instead of carrying an ongoing operating expense.
Specialized integrations
Hotels, healthcare and warehouses often need paging, door entry, analog devices or PMS integration that premise systems handle well.
| On-premise PBX | Hybrid | Cloud (UCaaS) | |
|---|---|---|---|
| Where call control lives | At your location | On site, with cloud features | Provider's data centers |
| How you pay | One-time purchase plus maintenance | Purchase plus some subscriptions | Monthly per-user subscription |
| If the internet goes down | Internal calls keep working | Internal calls keep working | Depends on failover to mobile app or backup |
| Remote and mobile work | Supported with softphones and VPN | Strong | Strongest |
| Best for | Stable, mostly on-site teams; strict control | Keeping existing phones while adding cloud features | Growing, distributed or remote teams |
Leaning toward the cloud? See business phone systems and connectivity & cloud, where we compare cloud phone and contact center providers for you.
Phone system services
Design & installation
- System sizing, licensing and call-flow design
- IP, digital and analog phones, headsets and conference phones
- Voicemail, auto attendant, hunt groups and call recording
- Paging, door phones and analog device integration
- Cabling and PoE switching we install ourselves
Lines, SIP trunks & carriers
- SIP trunking and number porting
- Backup circuits and analog failover
- Carrier quotes from 400+ providers through our connectivity team
- Copper (POTS) line replacement
E911 compliance
- Direct 911 dialing with no prefix (Kari's Law)
- On-site notification when 911 is called
- Dispatchable location sent with 911 calls (RAY BAUM'S Act)
Maintenance, repairs & changes
- Moves, adds and changes (MACs) and reprogramming
- Troubleshooting and repairs
- Software updates and system health checks
- Emergency response for outages
Running an NEC phone system?
In 2024 NEC announced it would exit the premises-based PBX business outside Japan, so new NEC systems and expansions are no longer available in North America. Your system doesn't have to stop working, but now is the time to plan.
- We keep your existing NEC system running with repairs and programming changes
- We assess what you have and what can be reused (cabling, phones, SIP trunks)
- We migrate on your timeline to an on-premise, hybrid or cloud system
- We port your numbers and cut over with minimal downtime
We'll review your NEC system, contracts and lines and lay out your options with clear pricing.
Request an assessmentPhone system platforms we install and support
Vendor-neutral: we recommend the platform that fits your users, features and budget.
On-premise & hybrid PBX
Mitel
Scalable business communications for single sites to multi-location organizations.
On-premise PBX
Allworx
All-in-one phone systems built for small and mid-sized businesses.
On-premise & hybrid PBX
Zultys
IP phone systems with built-in unified communications and contact center features.
Enterprise voice
Cisco
Enterprise call control and IP phones for larger and more complex networks.
On-premise PBX
ClearlyIP ComXchange
An on-premise phone platform, often used as a replacement for discontinued systems.
Poly & Enghouse Interactive
Poly (formerly Plantronics and Polycom) phones and headsets, and Enghouse Interactive contact center software.
How a phone system project works
- 1Free assessmentWe review your current system, lines, bills, cabling and how your team uses the phones.
- 2Options & quotePremise, hybrid and cloud options compared side by side with an itemized price.
- 3Install & cut overProgramming, number porting, E911 setup and a scheduled cutover, often after hours.
- 4Train & supportUser training, then repairs, changes and maintenance from a local team.
Premise phone system FAQ
What is an on-premise business phone system?
An on-premise phone system, or premise PBX, is a phone system whose call-control equipment is installed at your location rather than hosted in the cloud. It connects your desk phones, voicemail, auto attendant and call routing, and connects to the outside world through SIP trunks or traditional phone lines.
Should my business choose an on-premise or cloud phone system?
On-premise systems suit businesses that want to own their equipment, prefer a one-time capital purchase, need calls to keep working internally during an internet outage, or have strict security and control requirements. Cloud (UCaaS) systems suit businesses that want a monthly subscription, remote and mobile work, and less equipment to maintain. Hybrid systems combine both. ATEL installs all three and recommends one after reviewing your sites and needs.
Do on-premise phones work if the internet goes down?
Calls between extensions inside the building keep working on an on-premise system because call control is on site. Outside calls depend on how the system connects: SIP trunks need an internet or data circuit, so ATEL often designs a backup circuit or analog lines for failover.
NEC stopped selling phone systems. What should I do with my NEC system?
In 2024 NEC announced it would exit the premises-based PBX business outside Japan, so new NEC systems and expansions are no longer available in North America. ATEL keeps existing NEC systems running and helps businesses plan a migration, either to another on-premise PBX such as Mitel, Allworx, Zultys or ClearlyIP, or to a hybrid or cloud phone system, on a schedule that fits their budget.
Can I keep my phone numbers when I change phone systems?
In most cases yes. Business phone numbers can usually be ported to a new carrier or SIP trunk provider, and ATEL coordinates the port and the cutover so your numbers keep working.
What are Kari's Law and RAY BAUM'S Act, and do they apply to my phone system?
They are federal 911 rules for multi-line telephone systems. Kari's Law requires that users can dial 911 directly without a prefix such as 9 and that on-site staff are notified when 911 is called. RAY BAUM'S Act requires that a dispatchable location, such as the building, floor and room, is sent with 911 calls. ATEL configures new and upgraded systems to meet these requirements.
How much does an on-premise phone system cost?
Cost depends on the number of users and phones, the PBX platform and licenses, features such as voicemail, call recording and contact center, the number of locations, cabling, and SIP trunk or carrier costs. On-premise systems usually cost more up front and less per month than cloud systems. ATEL provides a free site assessment and an itemized quote.
Does ATEL repair and maintain existing phone systems?
Yes. ATEL provides repairs, troubleshooting, moves/adds/changes, programming changes and maintenance for existing business phone systems, and emergency response for outages.
Related solutions
Find the right phone system for your business
Book a free assessment. We'll review your current system, lines and bills, and compare premise, hybrid and cloud options with clear pricing.
ATEL Technologies, Inc. · 9580 Black Mountain Rd, Suite A, San Diego, CA 92126 · (858) 646-4600 · CSLB #1121116One Partner. Every Low Voltage & IT Need.