Migrate 60 Phones from Vendor to Grandstream

I’m moving our entire voice setup off a hosted provider and onto our own Grandstream Device Management System (GDMS). We have 60 identical Grandstream handsets; each one currently auto-provisions over Wi-Fi to the provider’s SIP server. I need that link severed and every phone reprovisioned so it registers seamlessly with our new Grandstream PBX/GDMS environment.

Key points you’ll handle
• Configure GDMS and any required UCM or cloud instance
• Build the new SIP trunks and extensions while keeping every existing phone number active
• Factory-reset or template-push the new config to all 60 phones so they auto-connect to our server instead of the old one
• Test inbound/outbound calling, caller ID, voicemail reachability, and Wi-Fi stability for each handset
• Provide clear documentation of the final setup so we can add or replace devices later without external help

All numbers must remain live during and after the cut-over, so careful planning around the porting window is essential. I’ll be onsite to reboot or reset devices as you direct, but all provisioning and GDMS work can be done remotely.

If you’ve completed Grandstream migrations before—especially zero-config or mass-provisioning projects—let me know your typical timeline and any tooling you rely on. Looking to schedule the switch as soon as we lock in the port date.