Comstel ICT · Business Landlines · Australia

Business Landlines
Reliable Voice. Modern Network.

In a world filled with modern business phone solutions, landlines remain a reliable and indispensable choice. Comstel offers business landline plans designed to deliver unmatched reliability, exceptional voice quality, and a variety of services and add-ons — from traditional phone lines through to SIP Trunking for businesses ready to upgrade to modern VoIP-based voice services.

Get a Free Quote SIP Phone Lines
Carrier-Grade Network HD Voice No Lock-In Local Support
Landlines
SIP Trunks
Reliable
Lower Costs
Smooth Transition
Side-by-side install with your current lines — no downtime, no productivity loss during the upgrade.
Why Business Landlines
Practical, Cost-Effective Voice for Australian Business

Choosing Comstel for your business landline plan is a practical and cost-effective decision. We tailor our plans to meet your unique requirements — from traditional copper landlines for businesses that need them, through to SIP Trunking for businesses ready to retire ageing PSTN/ISDN infrastructure and switch to modern VoIP voice services.

2
Voice Paths
Traditional & SIP
HD
Voice Quality
Crystal-clear calls
1-100+
Lines Per Site
Scale up or down
24/6
Local Support
Real Australian humans
Two Voice Paths
Choose Traditional Landlines or Modern SIP Trunking

Australian businesses run a mix of traditional copper landlines and modern SIP Trunks. Comstel supports both — helping you maintain reliable voice services today, and providing a clear upgrade path to SIP whenever you're ready.

Reliable Choice
Traditional Business Landlines
Copper-based PSTN and ISDN landline services for businesses that need traditional voice infrastructure. Reliable, well-understood, and supported by carrier-grade network infrastructure.
  • Reliable copper-based voice services
  • Local, national, and international call options
  • Mobile, local, & unlimited call packages
  • Tailored to your business call patterns
  • Low-cost, transparent pricing
  • Single point of contact for support
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Recommended Upgrade
SIP Trunking
SIP Trunking is the modern, VoIP-based replacement for PSTN and ISDN landlines. A digital equivalent of a phone line that delivers voice over your business internet connection — with lower costs, better scalability, and richer features.
  • Replaces traditional PSTN/ISDN lines
  • Reduced call rates — local & long-distance
  • Scale lines up or down without hardware changes
  • Carrier-grade infrastructure with redundancy
  • Side-by-side install — no downtime
  • Disaster recovery built in
View SIP Phone Lines
Why Move to SIP
Six Reasons Australian Businesses Switch to SIP Trunking
Reduced Call Costs
Lower Call Rates
Take advantage of significantly lower call rates compared to traditional telephony — on both local and long-distance calls. Eliminate redundant PSTN line costs and ad-hoc charges.
Increased Scalability
Scale Up or Down Easily
Easily scale your voice services as your business grows or changes — no expensive hardware upgrades, no complex system overhauls. Add or remove lines on demand.
Simple Management
Centralised Control
Easy-to-manage voice services with simple setup and centralised control. Reduce the complexity of managing traditional telephony with one provider, one bill, one team.
Unmatched Support
Reliable SLA Guarantees
Peace of mind with reliable support and strict uptime service level guarantees. Real Australian humans answer the phone — no offshore call centres, no chatbots.
Business Continuity
Robust Infrastructure
Carrier-grade infrastructure with redundancy built in — ensuring your operations continue seamlessly during potential outages, with disaster recovery measures designed for continuity.
Smooth Transition
Side-By-Side Install
Transition effortlessly to SIP Channels with our dedicated project management team and network engineers. Side-by-side install alongside your current lines — no downtime, no productivity loss.
SIP Features
What's Included with Comstel SIP Phone Lines
Carrier-Grade Network
Voice services delivered via Australia's most reliable telecommunications backbone — ensuring exceptional uptime and HD-quality voice clarity.
No Private IP Required
Comstel SIP Phone Lines work over any standard internet connection — no need for a dedicated IP network or locked-in NBN bundle.
Use Any Internet Provider
You're not tied to one internet provider. Keep your existing broadband while enjoying professional-grade voice services.
Scalable & Flexible
Add or remove lines as your business evolves. Whether you need one SIP line or 100, we'll grow with you.
VoIP-Ready
Seamlessly integrate with VoIP phones, cloud-hosted PBX systems, or hybrid office setups — including BizTel, Avaya Cloud, and iPECS Cloud.
Fast Setup
Get started quickly without complex installations or hardware dependencies. Easy deployment, minimal downtime, fast time to value.
How It Works
From Initial Quote to Live Service in Four Steps

Whether staying on traditional landlines or upgrading to SIP, Comstel manages the entire process — discovery, design, install, and ongoing support — with one dedicated point of contact.

1
Discovery
Understand your current voice setup, call volumes, line counts, and business call patterns. Identify the right path — traditional or SIP.
2
Design & Quote
Specify the right line count, call package, and integration with your existing phone system. Fixed-price quote with no surprises.
3
Side-By-Side Install
For SIP migrations, we install alongside your current lines so you can verify everything works before cutover. No downtime, no business disruption.
4
Cutover & Support
Smooth cutover with port management. Then ongoing local support, billing, & account management for the life of the service.
Why Choose Comstel
Australia's Trusted Business Voice Partner
30+
Years in Business
Serving Australia since 1992
Carrier-Grade
Premium network infrastructure
Real Local Support
Australian team, no offshore
24/6
Support Available
Real Australian humans
Frequently Asked Questions
Common Questions About Business Landlines & SIP
What's the difference between traditional landlines and SIP?
Traditional landlines use copper-based PSTN or ISDN infrastructure — the same lines that have served Australian businesses for decades. SIP Trunking delivers the same voice service over your business internet connection — lower cost, more scalable, and richer features. Same phone numbers, same dialling experience.
Can I keep my existing phone numbers?
Yes — your business phone numbers port across when you switch to SIP. Customers see no change. The porting process typically takes 2-4 weeks depending on your existing carrier; Comstel manages it end-to-end.
Will I lose service during the SIP migration?
No — Comstel does side-by-side installations. Your new SIP service is set up alongside your existing lines. You verify everything works, then we coordinate cutover with porting. There's typically no downtime and no productivity loss.
Do I need a special internet connection for SIP?
No — Comstel SIP Phone Lines work over any standard internet connection, no private IP required. Each active voice call uses about 100 Kbps, so a standard NBN 25 plan supports multiple simultaneous calls. Higher line counts may benefit from business-grade NBN or fibre.
What happens if my internet goes down?
Comstel SIP includes disaster recovery measures — calls automatically fail over to mobile or alternate routing if your primary internet fails. We design DR into the deployment for businesses where voice availability is critical.
How many SIP lines do I need?
A SIP line (or 'channel') supports one simultaneous call. If your peak concurrent calls is 5, you need 5 channels. Many businesses are over-provisioned on traditional lines — SIP often reduces line count and cost. Comstel reviews your call patterns during quoting.
Can I use SIP with my existing phone system?
Yes — SIP works with most modern phone systems and PBX platforms, including BizTel, Avaya Cloud, iPECS Cloud, and on-premise systems with SIP support. Comstel handles the integration during install.
How do I get started?
Click Get a Free Quote or call 1300 070 747. A Comstel specialist will respond same business day, review your current voice setup, and recommend the right path — whether that's traditional landlines, SIP, or a hybrid approach.

Future-proof your business voice

Free assessment, fixed-price quote, side-by-side install with no downtime. Comstel landlines and SIP Trunking deliver reliable voice services with the support of a real Australian team.

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Build the full voice stack

Pair landlines or SIP with cloud phone systems, business NBN, and video conferencing for fully integrated business communications.

SIP Phone Lines Cloud Phones BizTel Video Conference 1300 070 747
Business landline and SIP services delivered by Comstel ICT via carrier-grade Australian network infrastructure. Pricing varies by line count, call package, and configuration. Number porting timeframes depend on your current carrier — typically 2-4 weeks. SIP Phone Lines work over any standard internet connection.
Comstel ICT · 1300 070 747 · sales@comstel.com.au · comstel.com.au