The IT Manager's Complete VoIP Deployment Checklist

After deploying VoIP for 60+ organizations, I have distilled the process into a checklist that prevents every common mistake. Print this out, follow it in order, and your deployment will go smoothly.

Phase 1: Network Assessment (Week 1)

• [ ] Run bandwidth test from each location during peak hours (10 AM - 2 PM)
• [ ] Verify minimum: 100 Kbps per concurrent call (G.711) or 80 Kbps (Opus)
• [ ] Test jitter (must be < 30ms) and packet loss (must be < 1%)
• [ ] Confirm QoS support on all switches and routers
• [ ] Check if SIP ALG is enabled on firewall — disable it
• [ ] Verify VLAN support for voice/data separation
• [ ] Test WiFi coverage if softphones will be used wirelessly
• [ ] Document all firewall rules needed: SIP (5060-5061), RTP (10000-20000), STUN (3478)

Phase 2: Provider Selection (Week 2)

• [ ] Request proposals from 3+ providers
• [ ] Verify provider has data centers in your region
• [ ] Check provider's published uptime (not SLA — actual uptime)
• [ ] Confirm provider supports your compliance requirements (HIPAA, PCI, etc.)
• [ ] Test provider's support response time before signing

Phase 3: Configuration (Week 3)

• [ ] Create organizational structure (departments, locations)
• [ ] Set up user accounts and assign extensions
• [ ] Configure auto-attendant with professional greeting
• [ ] Set up ring groups (sales, support, management)
• [ ] Configure call queues with hold music and position announcements
• [ ] Set business hours and after-hours routing
• [ ] Configure voicemail greetings and email delivery
• [ ] Set up call recording policies
• [ ] Connect CRM integration and test call logging
• [ ] Configure E911 addresses for each location

Phase 4: Testing (Week 4)

• [ ] Test inbound calls to every number
• [ ] Test outbound calls from every extension
• [ ] Test call transfers (warm and cold)
• [ ] Test call queues under load (simulate 10+ concurrent calls)
• [ ] Test failover (disconnect primary internet, verify calls route to backup)
• [ ] Test mobile app functionality
• [ ] Test from remote/home locations
• [ ] Verify caller ID displays correctly on outbound
• [ ] Test fax if applicable (fax over IP or fax ATA)
• [ ] Run a full day pilot with 5-10 users

Phase 5: Migration (Week 5)

• [ ] Schedule port date (Tuesday-Thursday, never Friday)
• [ ] Notify all employees of changeover date
• [ ] Run 2-hour training session
• [ ] Distribute quick-reference cards for common operations
• [ ] Port numbers (allow 5-10 business days for local, 14-21 for toll-free)
• [ ] Verify ported numbers ring correctly
• [ ] Monitor call quality for first 48 hours
• [ ] Decommission old system after 2-week parallel run

Post-Deployment (Ongoing)

• [ ] Review call analytics weekly for first month
• [ ] Collect user feedback after 2 weeks
• [ ] Optimize ring group timing based on answer rates
• [ ] Schedule quarterly failover testing
• [ ] Review and update auto-attendant greeting seasonally

I have had good results with VestaCall (https://vestacall.com) for mid-market deployments provides a dedicated onboarding specialist who walks you through this entire checklist.