What is an IP PBX?
An IP PBX is the private telephone exchange that routes your business calls over your data network and SIP trunks instead of legacy copper lines. It connects your desk phones, softphones and mobile apps to each other and to the outside world, and adds features like auto-attendants, call queues, recording and video.
On-premise vs cloud vs software
- On-premise appliance — a physical box in your office. One-time cost, data stays in-house, full control.
- Cloud / hosted — the PBX runs in a data centre. Monthly cost, fast to roll out, ideal for remote-first and multi-site teams.
- Software / virtual — run the PBX on your own server or virtual machine for flexibility.
What to size and specify
- Number of users / extensions.
- Concurrent calls at peak.
- Trunk types: SIP, PRI/E1, analog FXO, or GSM.
- Features: IVR, call queues / call centre, recording, video, mobility apps, CRM integration.
- Redundancy and security (TLS/SRTP encryption, intrusion protection).
- Support, warranty and local availability.
Grandstream UCM vs Yeastar P-Series vs Epygi QX
| Criteria | Grandstream UCM6300 | Yeastar P-Series | Epygi QX |
|---|---|---|---|
| Best for | SMB to mid-enterprise; value and built-in UC | SMB to enterprise; flexible plans and apps | SMB; robust telephony, security and gateways |
| Deployment | On-premise appliance (+ remote access) | On-premise, software or cloud | On-premise appliance |
| Mobility app | Wave | Linkus | Softphone / apps |
| Trunks | SIP, PRI, FXO, GSM (via gateways) | SIP, PRI, FXO, GSM | SIP, PRI, FXO |
| Video & UC | Built-in with Wave | Strong via Linkus | Available |
Exact capacity and features vary by model — our team can map the right model to your user and call volumes.
How to choose — quick steps
- Count users and peak concurrent calls.
- Decide deployment: on-premise, cloud or software.
- List the trunks you must support (SIP, PRI, FXO, GSM).
- Shortlist must-have features (call centre, video, mobility, CRM).
- Match to a platform and model, then plan phones and network.
Where Cohesive Technologies fits
We're the authorised distributor for Grandstream, Yeastar and Epygi in India and South Asia, with pre-sales design, configuration and after-sales support. Pair your PBX with the right handsets from our Snom IP phones guide and a solid Grandstream network.
Key takeaways
- Pick deployment first: on-premise, cloud or software.
- Size by users, concurrent calls and trunk types.
- Grandstream UCM, Yeastar P-Series and Epygi QX each suit different needs — all available and supported locally.