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Embedded communications engineering

Lightweight SIP software and embedded voice gateways

ZMATRIX builds compact communications technology for products that need SIP, RTP, analog telephony and legacy-to-IP integration without unnecessary software complexity.

Explore SK400VOPView applications

Product portfolio

Purpose-built for embedded voice systems

Our portfolio combines reusable communications software with proven telephony hardware and custom engineering.

Software

SK400VOP Embedded SIP Stack

A compact SIP user-agent stack written for embedded applications, with SIP/SDP/RTP/RTCP, TCP/UDP/TLS, IPv6 and application-supplied networking and media callbacks.

  • Less than 200 KB stated runtime footprint including code and data
  • Designed for OS/RTOS portability and OS-less integration
  • Commercial licensing and integration support
SK400VOP product details →
Hardware · Limited inventory

IRIS4000 Dual-FXO Telephony Board

A compact two-port FXO board designed around Orange Pi Zero for PSTN-to-SIP gateways, PBX integration, IVR and custom analog telephony appliances.

  • Two FXO interfaces with caller-ID support
  • Asterisk/FreePBX integration path
  • Remaining assembled units available while inventory lasts
IRIS4000 availability and details →

Commercial product experience

Technology that has shipped and been licensed

ZMATRIX has sold assembled IRIS4000 telephony hardware and commercially licensed the SK400VOP SIP stack. The portfolio remains available where compact embedded communications technology is a better fit than a general-purpose VoIP framework.

Commercial SIP software

SK400VOP remains available for licensing, target-platform integration and product-specific interoperability work.

Shipped telephony hardware

IRIS4000 was produced and sold as a commercial product, with limited assembled inventory still available for suitable deployments.

Engineering continuity

The same protocol, embedded Linux and analog-telephony experience is available for migration and custom gateway projects.

More about ZMATRIX product experience →

Applications

Where embedded SIP still matters

These are integration problems where a small, controllable communications stack and purpose-built hardware remain valuable.

Radio over IP

Build SIP-based radio gateways and voice applications for dispatch, control-room and aviation-adjacent integration projects.

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Legacy PSTN Integration

Bridge analog telephone lines into SIP systems using compact embedded hardware and application-specific software.

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Embedded SIP Devices

Add standards-based SIP signaling to constrained devices without carrying a desktop-class software footprint.

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Custom Voice Gateways

Combine embedded Linux, SIP, RTP, analog interfaces and application logic into purpose-built communications appliances.

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Technical resources

Engineering guides for embedded communications

Practical architecture material for teams evaluating Radio over IP, ED-137, embedded SIP and analog-to-IP integration.

Radio over IP Gateway Architecture

Understand how SIP, RTP, PTT/COR and radio-facing hardware fit together in a purpose-built gateway.

Read the guide →

ED-137 for Radio over IP

Review current ED-137C/1 context and how historical ED-137B implementation work should be evaluated.

Read the guide →

Embedded SIP Stack Design

Separate signaling, media, networking, timers and platform services for maintainable embedded integration.

Read the guide →

FXO vs FXS

Learn which analog interface connects to a PSTN line, an analog phone, or a SIP gateway.

Read the guide →

Browse all technical guides →

Engineering model

Software IP plus practical integration

Portable C software

Use the SIP stack as a reusable signaling component and map networking, timing and media to the target platform.

Embedded hardware

Integrate analog telephony, ARM/Linux platforms and voice interfaces into compact gateway products.

Legacy migration

Extend the life of radio, intercom, paging and telephony systems by introducing standards-based IP connectivity.

Have an integration problem?

Talk directly with the engineering team.

For product licensing, remaining IRIS4000 inventory, customization or a new embedded communications design, contact sales@zmatrix.pk.

Contact ZMATRIX