How to Plan a VoIP Migration: Step-by-Step Guide

A VoIP migration done right delivers better call quality, lower costs, and powerful features. Done wrong, it disrupts business communications for days or weeks. This guide walks through every step.

## Phase 1: Assessment (2-4 Weeks)

### Network Readiness VoIP is only as good as your network. Before selecting a phone system: - **Bandwidth test** — Each concurrent call needs ~100 kbps. A 50-phone system needs at least 5 Mbps dedicated to voice. - **Jitter and latency** — Measure with tools like iperf3. Jitter should be under 30ms, latency under 150ms for toll-quality voice. - **Network switches** — Must support LLDP-MED or CDP for auto-provisioning and VLAN assignment. PoE switches eliminate separate phone power adapters. - **QoS configuration** — Voice traffic must be prioritized over data. Configure DSCP marking (EF for voice, AF31 for signaling) on all switches and routers.

### Current System Inventory Document everything about the existing phone system: - Phone numbers (main, DID, fax, toll-free) - Hunt groups and call routing rules - Auto-attendant menus and recordings - Voicemail boxes and users - Fax machines and analog devices - Paging systems and overhead speakers

## Phase 2: Design (2-3 Weeks)

### System Selection Choose between: - **On-premise PBX** — Grandstream UCM, FreePBX, or Cisco UCM. Full control, one-time cost, self-managed. - **Cloud PBX** — 8x8, RingCentral, or Vonage. Managed service, per-user monthly fee, provider handles updates. - **Hybrid** — On-premise PBX with SIP trunking to the PSTN. Local control with cloud flexibility.

### Network Design - Dedicate a separate VLAN for voice traffic - Configure QoS end-to-end (switch → router → WAN) - Size PoE switch capacity for all phones plus 20% growth - Plan for redundancy (dual switches, UPS on voice infrastructure)

## Phase 3: Implementation (1-2 Weeks)

### Pre-Cutover - Port numbers (submit LOA to new carrier 2-3 weeks before cutover) - Configure auto-attendant, hunt groups, and voicemail - Provision and stage all phones (firmware update, VLAN assignment, extension programming) - Test calls to every department and external numbers

### Cutover Day - Schedule during low-traffic hours (Friday evening or weekend) - Keep old system running in parallel until number port completes - Test every phone, every hunt group, every voicemail - Have rollback plan ready (SIP trunk can point back to old PBX)

## Phase 4: Training & Support (1 Week)

• Hands-on training for each department
• Quick reference guides at every desk
• Dedicated support contact for first 2 weeks
• Follow-up training at 30 days for advanced features

Summit DNC has migrated hundreds of businesses from legacy phone systems to VoIP across Southern California. We handle the network preparation, system design, number porting, and hands-on training.