Modernize your PBX without replacing everything at once.

Bridge a traditional PBX to SIP trunks, IP voice systems and new extensions through OpenVox analog, digital and SIP interworking.

OpenVox digital gateway connecting a traditional PBX to IP voice

The migration decision

Keep what works while the network evolves.

Many organizations still depend on existing extensions, numbering and trunk arrangements even when new sites or SIP services are being introduced.

A coexistence design avoids tying every improvement to one system replacement. OpenVox gateways create controlled analog, digital and SIP paths between the current PBX and the target voice environment.

Keep

Keep established PBX users

Retain the extensions and calling habits that still support daily work.

OpenVox gateway for legacy PBX interworkingOpenVox bridge layer
Add

Add new trunks or IP users

Introduce SIP connectivity, IP extensions or another site without forcing an immediate core replacement.

Migration paths

Choose what changes first.

PBX coexistence becomes easier to plan when analog, digital, SIP and expansion paths are separated clearly.

ANALOG

Connect analog PBX lines

Use FXO access where the existing PBX presents analog trunk or PSTN connections.

DIGITAL

Preserve E1/T1 interworking

Use digital gateway or DTU capacity for documented E1/T1/J1 and signaling requirements.

SIP

Introduce an IP voice core

Use SIP interworking to connect the legacy environment with an IP-PBX, softswitch or IMS network.

EXPANSION

Add users or another location

Extend calling without making the first project dependent on replacing every legacy component.

Move from PBX inventory to controlled coexistence.

Document the present system, select the correct interworking path, validate calls and migrate only the elements included in each phase.

  1. Inventory

    Record PBX model, trunks, extensions, numbering and required services.

  2. Select interfaces

    Match analog, digital or SIP roles to the existing network.

  3. Validate coexistence

    Test inbound, outbound, internal and cross-system calling behavior.

  4. Migrate in phases

    Move trunks, users or sites according to operational timing.

Verified interfaces for coexistence.

Based on OpenVox UCP, analog gateway and digital trunk documentation.

FXO interworking

OpenVox analog gateways and modules connect analog PSTN lines and PBX interfaces to SIP systems.

Proof chips
  • ANALOG

E1/T1/J1 access

Documented digital products provide selectable trunk and signaling options.

Proof chips
  • DIGITAL

IP voice interworking

UCP supports standard SIP trunks for IP-PBX, softswitch and IMS environments.

Proof chips
  • SIP

Behavior validated before cutover

Numbering, signaling, call routing and service requirements are confirmed during solution design.

Proof chips
  • PROJECT FIT

Turn your current PBX into a phased modernization plan.

Share the PBX model, trunk types, extension estate, target SIP system and migration priorities. OpenVox can help define the analog, digital and SIP interworking roles.