Phased plan
- Audit: numbers, users, devices, call flows, opening hours, hunt groups.
- Design: 3CX or Teams (Direct Routing/SBC), IVR/queues, recording, compliance.
- Network: QoS (DSCP EF), VLANs, bandwidth, 4G/5G failover.
- Porting: LOAs, split ports, test DDI ranges, fallback diverts.
- Staging: build tenants, import users, assign numbers/devices, test.
- Training: champions first, then all users; quick cards/videos.
- Cutover: pilot, wave schedule, hypercare & rollback plan.
Detailed checklist
- Confirm number inventory (DDIs, main lines, non-geo, fax, door phones).
- Capture call flows (IVR, queues, holidays, voicemail, overflow).
- Choose Teams Calling (Direct Routing/Operator Connect) or 3CX architecture.
- Order SBC/SIP trunks; validate codecs, TLS/SRTP.
- Define recording policy (announce/pause/redact, retention, access).
- Mark RTP DSCP EF (46), trust on switches; shape guest VLAN.
- Confirm EDR/antivirus exclusions for softphone apps.
- Build hunt groups, ring strategies, SLAs and wallboards.
- Stage handsets/DECT; push softphone configs; import contacts.
- Prepare LOAs, port dates, and test windows.
- Set diverts during port; confirm inbound/outbound CLI.
- Run pilot (10–20 users), collect feedback, fix issues.
- Wave cutover by site/team; staff hypercare lines.
- Decommission old trunks, update DR plans and docs.
Related guides
QoS for Voice & Video
Stop choppy calls.
VoIP for Bookings
IVR, queues & messages.
Data Security
GDPR, recording & RBAC.
Recently asked questions
How long do number ports take?
Single numbers can be days; multi-range or complex ports are typically 1–3 weeks. We use temporary diverts so no calls are lost.
3CX or Teams Calling?
Teams is great if you live in Microsoft 365. 3CX offers deep call-centre features and handset choice. We deploy both.
What’s the biggest risk?
Poor inventory and call-flow mapping. Our checklist removes unknowns and provides a tested rollback.