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Everything Your Business Relies On.Managed As One.

Managed IT, communications, security, workforce support, AI and digital infrastructure delivered under one accountable C9 team.

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CAPABILITIES

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CORE SOLUTIONS

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  • Business nbn
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  • Essential 8
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Headquarters

Level 3, 480 Collins Street
Melbourne VIC 3000

Direct Contact

1800 000 299

Email Intake

Sales@c9group.com.au
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Managed IT • Communications • Security • Workforce • AI • Digital Signage

We acknowledge the original communicators, connectors, and carers of the land and waters across Australia, the Aboriginal and Torres Strait Islander peoples. We pay our respects to Elders past, present, and emerging.

Business Voice Connectivity

Modernise Your Business Calling Without Operational Disruption.

Replace legacy ISDN and copper phone services with modern managed SIP connectivity. C9 handles the migration of your existing PBX, cloud voice, or Microsoft Teams environment with full number continuity and failover protection.

Business Continuity
Number Continuity
Voice Reliability
Managed Migration

Aging ISDN systems and unreliable providers create hidden business risk. Safely modernise your voice delivery today.

Australian office using existing PBX connected to modern SIP voice services
Managed Connectivity
Voice Failover Active
Voice Core
Geo-Redundant
Number Status
Protected
Businesses That Trust Us
CEVA Logistics
XWise Group
Forty Winks
Clarks
DCO
Novo
Chobani
Spendless Shoes
Ray White
Wild Rhino
Retail Care
The Entourage
CEVA Logistics
XWise Group
Forty Winks
Clarks
DCO
Novo
Chobani
Spendless Shoes
Ray White
Wild Rhino
Retail Care
The Entourage
Operational Fit

Is SIP Trunking Right for Your Business?

Replace legacy constraints with modern voice reliability. Identify the strategic drivers for modernising your calling environment.

You Still Use ISDN

Operational Challenge

Aging ISDN/Copper systems are end-of-life and increasingly unreliable.

Business Impact

Unexpected outages and high maintenance costs.

The SIP Solution

Transition to resilient IP-based voice with C9 managed SIP.

You Need to Keep Numbers

Operational Challenge

Fear of losing established business phone numbers during migration.

Business Impact

Loss of customer contact and brand disruption.

The SIP Solution

Expert managed number porting ensures full continuity.

You Have an Existing PBX

Operational Challenge

Legacy PBX hardware that isn't ready to be fully retired.

Business Impact

Fragmented systems and limited cloud capability.

The SIP Solution

Connect your current PBX to the modern voice core via SIP.

You Need Voice Failover

Operational Challenge

Lack of redundancy in case of local network or provider failure.

Business Impact

Total communication blackout during an incident.

The SIP Solution

Built-in automated failover routing for constant uptime.

Moving to Teams/Cloud

Operational Challenge

Disconnected systems while transitioning to modern workplace apps.

Business Impact

Inefficient workflows and user frustration.

The SIP Solution

Seamlessly bridge your voice services into Microsoft Teams.

Need Better Call Capacity

Operational Challenge

Scaling limitations with legacy line-based systems.

Business Impact

Busy signals and lost sales opportunities.

The SIP Solution

Instantly scale call capacity to match your business growth.

Operations manager reviewing voice continuity and call capacity dashboard
Migration Confidence

Modernising voice delivery shouldn't induce operational anxiety.

"We execute rigorous migration plans to ensure that your business stays connected at every phase. From number porting to system failover, we own the transition so you can focus on growth."

Voice Modernisation Journey

Replacing ISDN Safely.

A structured path from legacy constraints to modern voice reliability. We manage every step to protect your business continuity.

PHASE 01: ASSESSMENT

PBX & Number Audit.

We conduct a thorough audit of your current PBX hardware, line types, and phone number ranges. Identifying every dependency is critical for a safe migration.

Legacy PBX compatibility check
Complete phone number range audit
Network capacity & latency testing
Existing contract & porting review
Engineer reviewing SIP failover and business voice routing
PHASE 02: FAILOVER PLANNING

Ensuring Voice Reliability.

We design redundant voice pathways so your calls never drop. If your primary network fails, our managed SIP core automatically reroutes calls to secondary paths.

Failover Protection

Automated failover ensures your inbound customer calls reach your team even during local site disasters or internet outages.

Business team making reliable customer calls through managed SIP connectivity
PHASE 03: MANAGED CUTOVER

Number Continuity & Go-Live.

We manage the porting of your existing numbers from legacy ISDN into the SIP core. Our engineers own the go-live process, ensuring a zero-disruption cutover.

100%
Number Retention
ZERO
Migration Downtime
Operations manager reviewing voice continuity and call capacity dashboard

Modernise Business Calling Without Disrupting Operations.

C9 helps businesses transition from legacy voice services into managed SIP connectivity environments with migration planning, failover support, and operational continuity.

Unified Support
Accountability
Full Visibility
Operations
Safely Retired
Legacy ISDN
99.99% Assured
Continuity
Managed Voice Control

Accountable Support. No Generic Queues.

"We replace executive uncertainty with technical clarity. When voice delivery is managed correctly, it simply works."

Stop juggling hardware vendors and carriers. C9 provides a single point of accountability for your entire calling environment — from the core network to your desktop.

Improve Voice Reliability
Carrier-grade voice core with geo-redundant pathways to eliminate single points of failure.
Plan SIP Failover
Strategic automated routing to secondary networks or mobile devices during local outages.
Replace ISDN Safely
Expert management of the transition from legacy copper to high-performance IP voice.
Ready to Modernise?

Upgrade Legacy Voice Systems With Managed SIP Connectivity.

C9 helps Australian businesses modernise voice environments while protecting number continuity, business uptime, and operational communication reliability.

ISDN Replacement
PBX-to-SIP Migration
Failover Protection
Number Continuity
C9GROUP

Voice is Just the Foundation. See the Full Stack.

Reliable communication requires complete infrastructure control. Explore the solutions that integrate seamlessly.

Microsoft Teams CallingC9 Phone SystemInbound ServicesManaged IT Infrastructure
SIP VOICE REVIEW

Talk to C9 About Modernising Your Business Calling.

Interested in replacing legacy ISDN or improving your PBX reliability? Our specialists provide technical strategy and managed migration support.

Call us today: 1800 000 299

WHAT HAPPENS AFTER YOU SUBMIT

1. A real Australian calls you

Not a call centre. Not a script. Someone who actually knows IT.

2. We review your current gaps

We show you exactly where your infrastructure is exposed.

3. You get a clear roadmap

Plain English. Exact pricing. No lock-in or pressure.

Request a SIP Voice Proposal

Select your preferred engagement path below.

Engineer Review 2H Response

Direct Engineer Response. No Sales Pressure.

Common Questions

Frequently Asked Questions

Yes. We manage the entire number porting process, ensuring you maintain complete continuity with your customers without interruption.

Why leaders trust C9GROUP

Operations Manager

"We used to spend hours chasing different providers whenever a store lost connectivity. Now we call one team, they understand the full environment, and they own the issue through to resolution."

Operations Manager

National Retail Group

OneAccountable Team
Practice Manager

"Our clinicians cannot wait for technology problems to be passed between vendors. C9 stabilised the network, improved visibility across our clinics, and gave our team a clear escalation path."

Practice Manager

Multi-site Healthcare Group

12Clinics Supported
IT Director

"The biggest change is visibility. We can see what is happening across sites, understand recurring issues, and make infrastructure decisions before they become operational problems."

IT Director

National Distribution Business

24/7Active Monitoring
Managing Director

"C9 replaced a collection of disconnected suppliers with one practical technology roadmap. Support is faster, responsibilities are clear, and our leadership team finally has confidence in the plan."

Managing Director

Professional Services Firm

OneTechnology Roadmap
Operations Director

"Reliable warehouse connectivity is business-critical for us. C9 redesigned the network around how our teams actually work, removed the dead zones, and now proactively manages performance."

Operations Director

Logistics & Warehousing Group

ZeroKnown Dead Zones
Finance Manager

"The commercial value is not just lower supplier overhead. We now have predictable costs, clearer reporting, and a partner who explains where investment will make the biggest operational difference."

Finance Manager

Growing Australian Business

ClearMonthly Reporting
Operations Manager

"We used to spend hours chasing different providers whenever a store lost connectivity. Now we call one team, they understand the full environment, and they own the issue through to resolution."

Operations Manager

National Retail Group

OneAccountable Team
Practice Manager

"Our clinicians cannot wait for technology problems to be passed between vendors. C9 stabilised the network, improved visibility across our clinics, and gave our team a clear escalation path."

Practice Manager

Multi-site Healthcare Group

12Clinics Supported
IT Director

"The biggest change is visibility. We can see what is happening across sites, understand recurring issues, and make infrastructure decisions before they become operational problems."

IT Director

National Distribution Business

24/7Active Monitoring
Managing Director

"C9 replaced a collection of disconnected suppliers with one practical technology roadmap. Support is faster, responsibilities are clear, and our leadership team finally has confidence in the plan."

Managing Director

Professional Services Firm

OneTechnology Roadmap
Operations Director

"Reliable warehouse connectivity is business-critical for us. C9 redesigned the network around how our teams actually work, removed the dead zones, and now proactively manages performance."

Operations Director

Logistics & Warehousing Group

ZeroKnown Dead Zones
Finance Manager

"The commercial value is not just lower supplier overhead. We now have predictable costs, clearer reporting, and a partner who explains where investment will make the biggest operational difference."

Finance Manager

Growing Australian Business

ClearMonthly Reporting
Operations Manager

"We used to spend hours chasing different providers whenever a store lost connectivity. Now we call one team, they understand the full environment, and they own the issue through to resolution."

Operations Manager

National Retail Group

OneAccountable Team
Practice Manager

"Our clinicians cannot wait for technology problems to be passed between vendors. C9 stabilised the network, improved visibility across our clinics, and gave our team a clear escalation path."

Practice Manager

Multi-site Healthcare Group

12Clinics Supported
IT Director

"The biggest change is visibility. We can see what is happening across sites, understand recurring issues, and make infrastructure decisions before they become operational problems."

IT Director

National Distribution Business

24/7Active Monitoring
Managing Director

"C9 replaced a collection of disconnected suppliers with one practical technology roadmap. Support is faster, responsibilities are clear, and our leadership team finally has confidence in the plan."

Managing Director

Professional Services Firm

OneTechnology Roadmap
Operations Director

"Reliable warehouse connectivity is business-critical for us. C9 redesigned the network around how our teams actually work, removed the dead zones, and now proactively manages performance."

Operations Director

Logistics & Warehousing Group

ZeroKnown Dead Zones
Finance Manager

"The commercial value is not just lower supplier overhead. We now have predictable costs, clearer reporting, and a partner who explains where investment will make the biggest operational difference."

Finance Manager

Growing Australian Business

ClearMonthly Reporting