Calls when fixed lines are unavailable
Use a cellular trunk as the primary external voice route for a qualified site.
Use cellular trunks for business calls.
Integrate cellular voice channels into the PBX for primary, additional, or backup business calls. Keep mobile network access in the SIP call plan and route calls through the existing PBX.
When fixed lines are not suitable
Bring business calls to sites without fixed trunks.
Temporary sites, remote sites, and rapid branch openings may face unavailable fixed lines, long provisioning cycles, or a need for another route.
An OpenVox cellular gateway presents mobile voice channels to the PBX, allowing the project to define them as the primary, additional, or backup call route.
Add capacity for a specific route
Assign cellular channels to a particular call type, location, or operational requirement.
Provide another transport route
Route selected calls via cellular voice when the primary trunk cannot serve them.
Support a new or temporary location
Establish calls while the long-term site and transport design is still in progress.
Present mobile voice channels as a trunk that the PBX can route.
Cellular path to SIP
Present mobile voice channels as a trunk that the PBX can route.
The gateway connects to the cellular network on one side and the SIP or PBX environment on the other, with capacity and routing determined by the project.
Cellular network
GSM, WCDMA, or LTE voice service
GWP2120 gateway
Modular cellular channels and SIP trunk presentation
PBX / UCP
Routing, extensions, and business calls
Business users
Desk phones, branch, or temporary site
Use the GWP2120 for modular capacity, with the SWG only as a defined alternative.
The GWP2120 is the primary 4‑to‑44-channel path in this solution; the SWG‑3016 remains a fixed 16-channel option when this capacity model suits the site.
Capacity verified for each trunk role.
Operator approval, connection rate, and costs remain outside the scope of the stated solution.
GSM/WCDMA/LTE channels
OpenVox cellular gateway and UCP documentation covers mobile voice access.
Primary or backup use
Documented deployments use wireless voice as a primary or alternate trunk.
PBX interoperability
Cellular channels connect to the calling environment through a defined SIP or platform role.
Operator requirements confirmed
SIM, numbering, routing, and local operator rules remain part of the project evaluation.
Plan a defined cellular call route.
Share the location, operator, expected number of simultaneous calls, PBX, numbering requirements, and primary or backup role. OpenVox can help map gateway capacity and SIP routing.
Related products
OpenVox VS-GWP2120 GSM/WCDMA/LTE Wireless Gateway
Up to 11 plug-in GSM/WCDMA/LTE modules; supports 4 to 44 channels and 2 Ethernet ports.
OpenVox SWG-3016/32-4S G/W/L Series Wireless Gateway
Supports multiple codecs; automatic SIM switching based on policy; dynamic SIM card allocation;
Let’s discuss your project
Describe your requirements. Our team can help you select and plan your OpenVox solution.