Bespoke VoIP Solutions

Finally, a Phone System That Does What You Tell It.

Bespoke VoIP platforms that fit your workflows exactly, integrate cleanly with your systems, and scale without drama - so you stay in control of costs, features, and future decisions instead of waiting politely for a supplier to catch up.

Fix Our VoIP Now

When Voice Becomes the Bottleneck, Everything Slows Down

Calls still carry revenue, service delivery, and risk - yet many businesses are stuck with voice systems that don't match how work actually happens. When routing is rigid, reporting is patchy, and changes require supplier tickets, the cost shows up fast: longer handling times, missed hand-offs, frustrated customers, and operational teams forced to patch the gaps with manual workarounds.

The damage compounds as volumes grow, teams spread across locations, and compliance expectations tighten. Legacy constraints, security exposure, and integration gaps turn "just telephony" into a blocker for delivery. What's needed is a bespoke platform that fits real call journeys, integrates cleanly with core systems, and can be engineered around exact requirements - with the freedom to evolve without being held hostage by licensing or vendor limitations.

Here's what a bespoke VoIP solution can deliver:

  • Workflow-led call control tailored to real routing, queues, and escalation paths
  • Clean integrations with CRM, helpdesk, identity/SSO, billing, and data pipelines
  • Security and compliance controls aligned to specific risk and audit requirements
  • Predictable scalability for higher volumes, more sites, and remote teams
  • Resilience by design with redundancy, failover, and clear operational runbooks
  • Open-source foundations with custom engineering to reduce lock-in and keep control in-house

If voice is creating drag, cost, or risk, it's time to replace "best-effort" telephony with a platform engineered to match the business - share the constraints and edge cases, and a clear, buildable plan follows. Fix Our VoIP Now

Platforms & Technologies We Work With

Non-exhaustive - depends on requirements.

  • Core Softswitch & Media

    FreeSWITCH, Asterisk, Yate

  • SIP Edge, Routing & Load Balancing

    Kamailio, OpenSIPS

  • Media Proxy, NAT Traversal & SRTP

    rtpengine, RTPProxy, MediaProxy

  • Application Logic & Call Control

    Custom call applications (e.g., drachtio where appropriate)

  • Security & Hardening

    TLS/SRTP, SIP edge protections, rate limiting / abuse controls, automated failover patterns

  • Integrations & Middleware

    Custom APIs and middleware for CRMs, ticketing, identity/SSO, billing, data pipelines

Use Cases for Faster Answer Times, Better Routing, and Less Manual Work

Practical examples of where bespoke engineering unlocks better outcomes - from protocol-layer work through to operational change, interoperability fixes, and targeted functionality changes.

Protocol-Layer Integration and SIP Interoperability
Bridge mismatched SIP implementations, normalise headers, manage SDP quirks, and integrate cleanly with carriers, SBCs, and third-party platforms.

Functionality Changes and Feature Behaviour Tweaks
Adjust call handling logic (and edge-case behaviour) when off-the-shelf features don't map to how your teams actually work.

Workarounds for Vendor Constraints
Replace unreliable patches with engineered alternatives that are testable, supportable, and designed to survive upgrades and growth.

Contact Centre Call Flow Modernisation
Rebuild IVR, overflow, prioritisation, and escalation paths so the right calls reach the right teams quickly, with clear ownership.

CRM-Linked Calling and Screen Pops
Connect call events to customer records so teams get context at the point of answer and outcomes are captured consistently.

Multi-Site and Remote Workforce Voice
Maintain consistent policies and routing across sites and home working, with role-based access and predictable control.

Secure Call Recording and Retention
Implement recording, encryption, retention rules, and access controls aligned with governance and audit expectations.

SIP Interconnect and Carrier Resilience
Improve uptime and call quality with smarter routing, redundancy, and failover across trunks and regions.

Billing, Rating, and Cost Controls
Add usage visibility, anomaly detection, and cost management controls where standard platforms fall short.

Operational Alerting and Monitoring
Make voice observable with metrics, alerting, and incident-ready runbooks for faster, calmer resolution.

Core VoIP Capabilities & Outcomes

Our bespoke VoIP solutions are engineered for reliability, control, and long-term adaptability - ensuring your voice platform remains an asset, not a constraint.

VoIP by Industry

Bespoke VoIP delivers the most value when designed around real operational pressures rather than abstract features. We build voice platforms that support daily workflows, regulatory requirements, and growth patterns across industries.

Telecoms

High-volume call routing, SIP interconnects, and carrier-grade resilience for uninterrupted service delivery.

E-commerce

Integrated voice and CRM workflows that improve customer support responsiveness and order handling.

Healthcare

Secure, compliant communication supporting clinical teams, patient coordination, and telemedicine.

Education

Reliable voice services for campuses and remote learning environments, supporting staff, students, and administration.

Logistics

Real-time voice connectivity for dispatch, drivers, warehouses, and customer service teams.

Hospitality

Unified guest communication and internal coordination across properties and departments.

From Design to Go-Live: Our Implementation Process

We don't deploy one-size-fits-all platforms. Every VoIP deployment is built around your technical environment and operational goals. We follow a structured, collaborative process to ensure reliability from day one and flexibility for the future.

  • 1

    Discovery & Requirements Mapping

    We review your current telephony platform, network topology, user groups, and call-critical workflows. We also capture compliance requirements, reporting needs, and growth targets so the platform is designed for what you must deliver, not just what you have today.

  • 2

    Solution Architecture & Detailed Design

    We produce a tailored architecture covering SIP routing, media handling, redundancy, and security controls. We define call flows, numbering, dial plans, integration points, and operational runbooks so there is a clear blueprint before build begins.

  • 3

    Build, Test & Controlled Migration

    We implement the platform, then validate behaviour with structured testing across call flows, failover, and load scenarios. Migration is planned to minimise disruption, including phased cutovers, SIP trunk integration, number porting coordination, and rollback options where required.

  • 4

    Operational Handover & Support Options

    We provide documentation and knowledge transfer tailored to your team's responsibilities, from day-to-day operations to change management. Ongoing support is available through SLA-Based Technical Support or Dedicated Support Hours, depending on your needs.

Why Choose Onyxsis?

Proven Outcomes in the Real World

Real results. Real measurements. Real impact.

View Case Study

In our Inter-Protocol Transcoder case study, we delivered a solution that removed long-standing SIP call-control constraints inside a proprietary environment. The result was a 22% reduction in support tickets linked to call control issues and a 15% reduction in complaints about call disruptions.

22% reduction
support tickets linked to call control issues
15% reduction
complaints about call disruptions

We also achieved a 99.995% success rate for SIP call feature usage, showing consistent performance under real operational load. That's the level of expertise we bring to every project: measurable impact, clearly defined, and delivered without hand-waving.

Open-Source Values, Bespoke by Default

Open source isn't a buzzword for us; it's how we protect your freedom to evolve without vendor constraints. Every engagement is tailored to your business, with practical engineering choices that prioritise long-term control and clarity.

A Specialist Team Built for the Hard Stuff

We're the partner you call when the problem is messy, high-stakes, and everyone else is reaching for a workaround. Our engineers stay accountable end-to-end, and we keep you in control with straight answers, clear options, and a plan you can challenge.

Support That Doesn't Disappear After Go-Live

After go-live, we stay close to your team with proactive guidance, optimisation, and hands-on troubleshooting as call volumes, workflows, and priorities shift. You'll always know what's happening, what we recommend next, and why.

If you need formal response targets and ongoing assurance, we offer SLA-Based Technical Support to keep risk under control. If you want flexible access to our engineers for improvements and change, Dedicated Support Hours give you predictable capacity without the overhead.

If you're ready to stop compromising on voice, we'll help you turn your requirements into a platform you can genuinely own and grow. Tell us what's not working, what must not fail, and what "better" looks like - and we'll build the route to get you there.

Talk to Our Team

Frequently Asked Questions

Still have questions? Contact Us - our team is here to help.

Make Your VoIP Behave Like It's Part of the Business

Designed around real workflows, not brochure features or "best practice" guesses.

Build Our Bespoke VoIP