Scaling a phone system past a few hundred extensions usually triggers the same unpleasant surprise: per-user licences, per-feature activation fees and a recurring subscription. The UC500H Hybrid IP-PBX is built for organisations that want enterprise unified communications without that invoice. It registers up to 1,000 users, carries 100 concurrent calls, ships with integrated FXO trunk ports and FXS ports with lifeline capability, and requires no licensing fees, no cost-per-feature and no recurring charges.
It is also hybrid by design, which matters more than the user count: PSTN lines and VoIP trunks run side by side, so a site can keep the copper it already pays for while moving everything else onto SIP.
What “hybrid” means here
Most IP-PBX appliances assume a pure-IP world. Real sites rarely are. A hybrid IP-PBX has analog interfaces built in:
- FXO trunk ports terminate PSTN lines from the carrier, so existing numbers keep working.
- FXS ports with lifeline capability support analog telephones — and keep a working phone available if the IP network or power to the LAN fails.
- SIP trunk accounts — up to 80 — connect hosted providers, branch offices or ITSPs alongside the analog lines.
The result: one appliance serves a building where the reception still uses a wall phone, the finance team has IP handsets, and the carrier lines have not been cancelled.
Capacity and hardware
Features that decide real deployments
Call routing that follows the organisation. Customisable call routing, multi-level IVRs, call queues, auto-attendant and a flexible dial plan. Inbound routing can be automated with autoclip, which matches a caller’s number against previous calls so repeat customers reach the same team without pressing anything.
Multi-site by default. Multi-site peering links branches into one dial plan, and moveable extension keeps a number with a person rather than a desk — useful for hot-desking, hybrid work and staff who move between floors.
Records and reporting. Call detail records (CDR) are captured for accounting and audit, with a call-records server available.
Messaging that leaves the phone system. Voicemail and fax forwarding to email, LDAP and XML phonebooks, and a multi-language auto-attendant.
Security without a separate appliance. SRTP, TLS and HTTPS protect signalling and media; the built-in firewall and NAT router handle the edge; ACLs and data filtering add policy control.
Where a 1,000-user hybrid IP-PBX fits
- Growing head offices that have outgrown a mini IP-PBX and refuse to pay per-seat licences
- Multi-site organisations (branches, clinics, campuses, warehouses) needing one dial plan and central CDR
- Mixed estates where analog handsets, fax machines and PSTN lines must survive alongside IP phones
- Call-centre style operations with queues, IVR trees and 100 concurrent calls
- Public-sector and education sites where unpredictable recurring licence costs are the main objection
If a site is smaller — 60 to 300 SIP users — the UC200-15, UC200-30, UC200-45 and UC200-60 cover that range with the same licensing-free model and integrated FXO/FXS ports, and the two families interoperate: a branch on a UC200 can peer into a UC500H at head office.
Deployment notes that save a project
- Count concurrent calls, not just users. 1,000 registered users with 100 concurrent calls suits a large office where a fraction of staff are on the phone at once; a call centre with 120 agents on shift needs a different conversation.
- Use FXS lifeline ports deliberately. Put at least one analog phone on an FXS port near reception or security — it keeps working when the LAN does not.
- Keep a few FXO ports even on SIP-first sites. They carry calls when the internet link drops, and they preserve numbers the business cannot lose.
- Plan the NAT story early. Super NAT adaptability removes per-extension NAT configuration for remote users, but site firewalls still need the right ports open.
- Automate provisioning before rollout. Auto-discovery and auto-provisioning decide whether 200 handsets take a day or a month.
FAQ
Q1. What is a hybrid IP-PBX? An IP-PBX appliance with analog interfaces built in — FXO ports for PSTN trunk lines and FXS ports for analog telephones — so an organisation can run PSTN and VoIP networks side by side instead of choosing one.
Q2. How many users and calls does the UC500H support? Up to 1,000 registered users, up to 80 SIP trunk accounts, up to 100 concurrent calls and up to 50 conference attendees, on a 1.5 GHz ARM quad-core platform with 1 GB RAM and 8 GB flash.
Q3. Are there really no licensing fees? Yes. The UC500H is positioned without licensing fees, costs-per-feature or recurring fees — you buy the appliance, not a subscription.
Q4. Does it work with SIP phones from other brands? It is SIP-based and interoperates with mainstream SIP endpoints. Remote extensions register without NAT traversal settings thanks to super NAT adaptability.
Q5. Can it peer with another IP-PBX or branch? Yes — multi-site peering is supported, which is how a UC200 at a branch and a UC500H at head office share one dial plan.
Q6. Is the UC500H suitable for a 60-user office? It works, but the UC200-15 or UC200-30 is a better economic fit at that size. Move to the UC500H when user counts, concurrent calls or multi-site peering exceed the smaller platform.
The bottom line
The UC500H answers a specific question: can we get enterprise unified communications — 1,000 users, IVR, queues, CDR, multi-site peering, encryption — without a per-seat licence model? On this hardware, yes, and the integrated FXO/FXS interfaces mean the migration does not force anyone to abandon a working analog line or handset on day one.
Tell us your user count, concurrent call peak, how many PSTN lines you intend to keep and whether branches need peering, and we will size the platform accordingly.
