When it comes to connecting your business to the internet in Australia, the National Broadband Network (NBN) offers multiple connection types designed for different needs. One of the most common options is NBN TC4 — short for Traffic Class 4. But what does it actually mean, and how does it affect your business’s internet performance?

In this guide, we’ll unpack NBN TC4, explore how it works, and help you determine whether it’s the right fit for your business.

Understanding NBN and Traffic Classes

Before diving into TC4 specifically, it’s helpful to understand that the NBN uses “traffic classes” to categorise the type of connectivity services delivered over its network. These classes define how different types of traffic are prioritised and delivered.

• Traffic Class 1 (TC1): High-priority traffic, typically used for voice services like VoIP.
• Traffic Class 2 (TC2): Used for enterprise-grade services requiring consistent performance.
• Traffic Class 4 (TC4): The standard class used for residential and business broadband internet.

What is NBN TC4?

NBN TC4 is the default and most commonly used traffic class for standard broadband services in Australia — both for homes and small businesses. It provides best-effort internet access, meaning speeds and performance may vary depending on network congestion and other factors.

TC4 is designed for general internet usage such as:

• Web browsing
• Email
• Cloud applications
• Streaming
• Video conferencing
• File transfers

It is the connection type you'll get with most NBN plans from major ISPs unless you specifically request a business-grade alternative like TC2.

How Does NBN TC4 Work?

TC4 operates on a shared network model, meaning your connection shares bandwidth with other users in your area. This can lead to fluctuations in performance — especially during peak periods like evenings or working hours.

Each TC4 service is delivered with two key speed components:

• Access Line Speed: The maximum physical speed supported by your NBN connection type (e.g., 100/40 Mbps).
• CVC (Connectivity Virtual Circuit): This is the shared capacity your ISP purchases from NBN Co. The more capacity they buy, the better your speeds during busy times.

Connection Types that Use TC4

TC4 is available across most NBN access technologies, including:

• Fibre to the Premises (FTTP)
• Fibre to the Node (FTTN)
• Fibre to the Curb (FTTC)
• Hybrid Fibre Coaxial (HFC)
• Fixed Wireless
• Satellite

The actual performance will depend on your physical infrastructure and service provider provisioning.

Is NBN TC4 Suitable for My Business?

For many small to medium-sized businesses, NBN TC4 is more than sufficient — especially if your operations are cloud-based and involve moderate bandwidth usage.

Ideal if your business:

• Has 1 to 20 staff
• Relies on cloud platforms like Microsoft 365 and Unified Communications as a Service
• Runs VoIP with Quality of Service enabled
• Uses file sharing and video calls occasionally
• Doesn't require guaranteed uptime or symmetrical speeds

Not ideal if your business:

• Has large-scale data transfers
• Needs guaranteed speed and low latency
• Runs critical services with zero tolerance for outages
• Operates outside of typical 9–5 business hours and needs consistent off-peak performance

In those cases, you may consider NBN TC2, enterprise Ethernet, or fibre services — which BIT365 can also help configure and manage.

Limitations of TC4

While TC4 is a cost-effective and flexible solution, it does come with limitations:

• No guaranteed speeds — performance depends on your ISP’s network capacity
• Contended bandwidth — shared with other users in your area
• Lower Service Level Agreements (SLAs) compared to business-grade services
• Limited prioritisation — not suitable for mission-critical applications

For businesses where downtime equals lost revenut, having a cyber incident response plan in place is critical - especially if reluing on a shared connection like TC4.

Enhancing TC4 with Managed IT Services

If you're using TC4 for your business, working with a Managed Service Provider (MSP) like BIT365 can ensure you're getting the most out of your connection - here's why IT support is essential for business of all sizes.

We can help:

• Optimise your local network setup
• Implement cloud performance enhancements
• Prioritise voice/video traffic through Quality of Service (QoS)
• Monitor internet performance and troubleshoot bottlenecks
• Scale your internet strategy as your business grows

Checklist: What to Consider Before Choosing NBN TC4

✅ Check your business’s typical bandwidth usage
✅ Understand your peak-hour internet demands
✅ Confirm what speed tiers are available in your area
✅ Compare options with business-grade NBN or fibre
✅ Speak with an MSP to design a network that fits your goals

NBN TC4 – A Solid Starting Point

NBN TC4 is the go-to choice for most Australian small businesses looking for a reliable and affordable internet connection. While it’s not the most premium option available, it often delivers excellent value when paired with the right support and optimisation.

If your business is growing or you need more stable, consistent performance - or you're thinking about protection your operations with cybersecurity insurance - BIT365 can assess your needs and help you transition to a more advanced connectivity solution.

🚀 Ready to Optimise Your Business Internet?

BIT365 provides tailored internet and networking solutions for Australian businesses. Whether you’re sticking with NBN TC4 or upgrading to a high-performance connection, we can help you choose, configure, and manage the right solution.

Contact us for a consultation today.

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