Guide · Comparison
On-premise PBX vs cloud telephony
A point-by-point breakdown: what to pick for a 50-seat office, a private home, a call center. CapEx vs OpEx, reliability, security, integration, migration. Honest, no marketing fluff.
What is an on-premise PBX
A physical server (or hardware/software appliance) sitting in your server room. You buy it, install it, maintain it. iPECS UCP, Panasonic KX-NS, Avaya IP Office, Asterisk on a dedicated server — all on-premise. All calls go through your hardware, your network, your extension lines.
What is cloud PBX
It is a service. You rent a virtual PBX from a provider (MTT, Beeline, Mango, Telfin, Dom.ru, Zoom Phone, RingCentral, 3CX hosted, FreeSWITCH-cloud). Each employee has a softphone on PC/smartphone or a SIP phone at the office. Numbers and logic live in the provider cloud.
CapEx vs OpEx
On-premise — CapEx: pay 200–800k ₽ upfront for hardware, then only maintenance. Cloud — OpEx: monthly 500–2500 ₽ per employee. Over 5 years for 50 extensions: on-premise ~600k ₽ upfront + 100k/year service; cloud ~1.2M ₽ over 5 years. Cloud is more expensive in the long run, but needs no upfront investment.
| Item | On-premise | Cloud |
|---|---|---|
| Upfront (50 ext.) | 350 000 ₽ | 0 ₽ |
| Monthly | 0 ₽ | 75 000 ₽ |
| Annual maintenance | ~90 000 ₽ | included |
| 3-year total | 620 000 ₽ | 2 700 000 ₽ |
| 5-year total | 800 000 ₽ | 4 500 000 ₽ |
Note: cloud pricing varies wildly by feature set. Basic — 500 ₽/ext, advanced (recording, IVR, CRM) — 1500–2500 ₽/ext.
Reliability
On-premise does not depend on external providers. SIP carrier outage — internal office calls keep working. PSTN line damaged — internal comms still works. Cloud: if Internet or provider goes down, no comms. Critical for call centers and 112 services.
Security
On-premise — data stays within your perimeter. Suitable for FZ-152, banking secrecy, state secrets. Cloud — data lives at the provider. Need to verify their certifications (PCI DSS, ISO 27001), data center location, encryption. For some industries, regulators simply forbid cloud.
Functionality
On-premise PBX like iPECS UCP, Avaya Aura, Cisco Unified CM beats cloud on feature depth: complex call flows, multi-level IVR, project-tagged recording, deep 1C integration, priority queues, supervisor mode. Cloud wins on simplicity: switch on and it works.
| Feature | On-premise | Cloud |
|---|---|---|
| Basic calls, transfer, hold | ✓ | ✓ |
| Multi-level IVR | ✓ (any complexity) | ✓ (limited) |
| Priority queues, supervisor | ✓ | Pro tier only |
| Tagged call recording | ✓ | ✓ |
| Deep 1C integration | ✓ (via API) | limited |
| Analog lines/fax | ✓ | no |
| DECT infrastructure | ✓ (Gigaset N870) | no |
| Local SIP trunks with QoS | ✓ | no |
| Video in call | ✓ (separate solution) | ✓ |
Scaling
Cloud: hire employee → buy license → done in 5 minutes. On-premise: add expansion board, reconfigure, install phone. For 5–50 seats the gap is small. For 500+ on-premise wins — cloud licenses cost more than a one-time hardware expansion.
When to pick what
Cloud — startup, small office, temporary project, remote team, no server room. On-premise — mid-size and large business, call center, security requirements, long planning horizon, service budget. Hybrid — local PBX + cloud SIP trunk (our favourite).
On-premise
Mid and large business, call center, security requirements, long planning horizon.
Cloud
Startup, small office, remote team, temporary project.
Hybrid
Local iPECS UCP + cloud SIP trunk. The best of both worlds. Our favourite.