Migrating from Legacy PBX to Cloud VoIP: A Step-by-Step Guide
Migrating from a legacy PBX to cloud-hosted VoIP can cut telecommunications costs 30-50% while adding modern features like video conferencing, mobile integration, and analytics. Here's the proven approach.
Phase 1 — Assessment (Week 1-2)
- Inventory all phone lines, extensions, hunt groups, and auto-attendants - Document call flows and after-hours routing - Audit network infrastructure for VoIP readiness (bandwidth, QoS, PoE) - Identify integration points (CRM, contact center, paging)
Phase 2 — Design (Week 2-3)
- Select platform (Cisco UCM Cloud, Microsoft Teams Phone, RingCentral) - Design call routing with failover paths - Plan number porting timeline with carriers - Configure QoS policies on switches and routers (DSCP EF for voice, AF41 for video)
Phase 3 — Infrastructure Prep (Week 3-4)
- Upgrade PoE switches if needed (PoE+ for video phones) - Deploy dedicated voice VLAN - Install/configure SBC (Session Border Controller) for SIP trunking - Set up monitoring for MOS (Mean Opinion Score) tracking
Phase 4 — Deployment (Week 4-5)
- Deploy IP handsets in waves (department by department) - Port numbers during low-traffic windows - Run parallel systems for 48-72 hours - Train end users on new features
Phase 5 — Optimization (Ongoing)
- Monitor call quality metrics (jitter, latency, packet loss) - Fine-tune QoS based on real traffic patterns - Decommission legacy PBX hardware
Summit DNC has completed VoIP migrations for corporate campuses, medical offices, law firms, and hotel properties across Southern California.
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