Keep established PBX users
Keep the extensions and calling habits that still support daily work.
Modernize your PBX without replacing everything at once.
Keep a traditional PBX and its established extensions while introducing SIP trunks, IP calls and new users around it. Modernize external connections in phases and validate coexistence before each cutover.
The migration decision
Keep what works while the network evolves.
Many organizations still depend on existing extensions, dialing and trunk arrangements even when a new site or SIP services are introduced.
A coexistence design avoids tying every improvement to a single system replacement. OpenVox gateways create controlled analog, digital and SIP paths between the current PBX and the target voice environment.
Add new trunks or IP users
Introduce SIP connectivity, IP extensions or another site without forcing an immediate core replacement.
Move according to business priority
Separate trunk, site and endpoint migration into manageable project phases.
Use the interface that matches the existing PBX
FXO connects analog PBX lines, digital gateways or DTU modules connect E1/T1 services, and SIP trunks link the environment to IP-PBX, softswitch or IMS systems.
Move from PBX inventory to controlled coexistence.
Document the current system, select the correct interoperability path, validate calls, and migrate only the elements included in each phase.
Inventory
Record the PBX model, trunks, extensions, numbering, and required services.
Select the interfaces
Match analog, digital, or SIP roles to the existing network.
Validate coexistence
Test incoming, outgoing, internal, and inter-system call behavior.
Migrate in phases
Move trunks, users, or sites according to operational timing.
Combine analog, digital, and SIP interoperability where needed.
Product selection follows the existing PBX interfaces, trunk capacity, target IP system, and migration sequence.
Interfaces verified for coexistence.
Based on OpenVox UCP, analog gateway, and digital trunk documentation.
FXO interoperability
OpenVox analog gateways and modules connect analog PSTN lines and PBX interfaces to SIP systems.
E1/T1/J1 access
Documented digital products offer selectable trunk and signaling options.
IP voice interoperability
UCP supports standard SIP trunks for IP-PBX, softswitch, and IMS environments.
Behavior validated before cutover
Numbering, signaling, call routing, and service requirements are confirmed during solution design.
Modernize your PBX without replacing functional infrastructure.
Share the PBX model, trunk types, extension status, and target SIP system. OpenVox can define analog, digital, and SIP interoperability roles for a controlled transition.
Related products
OpenVox iAG800 V2 Series Analog VoIP Gateway
Supports 2/4/8 FXO/FXS combo ports; Uses standard SIP protocol; Compatible with leading IMS/NGN platforms, IPPBX, and SIP servers.
OpenVox DGW-L302 Series E1/T1/PRI VoIP Gateway
Supports 2 software-selectable T1/E1/PRI interfaces; supports 60 concurrent calls.
Let’s discuss your project
Describe your requirements. Our team can help you select and plan your OpenVox solution.