The evolution of voice services.

August 7 2017, by Macquarie Telecom Group | Category: Telecom

Continuous evolution and innovation in technology means products and services are always being superseded with something faster, smarter and more efficient.

Telephony evolved from copper-based analog networks, to the digital technology of ISDN to accommodate voice and data and minimise signal noise. Now it’s time for ISDN to make way.

Goodbye ISDN, hello SIP

IP-based networks are nothing new, but faster fibre-based networks such as the NBN treat voice as data. It’s the end of the line for ISDN – Telstra has entered an end of sale process with ISDN services phased out from early 2018, and disconnection likely from 2019.

Voice traffic will be carried across data networks using Session Initiation Protocol (SIP). The transition is an opportunity to:

  • reduce costs
  • scale on demand
  • boost productivity
  • mobilise your workforce
  • offer resilience and disaster recovery pathways.

Evolution that reduces costs

SIP removes the need for expensive PBX hardware in each location, and separate voice and data technologies. The voice gateway is centralised in either a Data Centre or head office and connected to branch locations via traditional private MPLS networks or the Internet. Consolidating infrastructure can lead to significant cost reductions.

Under National Number Hosting, all geographical numbers are centralised into one location – either a physical PBX housed in a Data Centre or a hosted voice platform. In keeping with cloud market trends, voice is consumed ‘as a service’ and moves from a CAPEX to OPEX model.

Costs are reduced by:

  • moving ISDN and PSTN to network access costs, and reducing voice spend per site
  • free internal calls across sites as voice traffic uses the data network – the traditional voice network costs apply only when calling outside your network
  • reducing the number of local ISDN channels no longer needs be on a per site basis. Using your staff numbers and average concurrent call volumes, a ratio of 3:1 of staff to channels could make a big impact on reducing licencing and access costs, without compromising capacity.

No business interruptions

SIP helps you maintain business continuity and manage disaster recovery. With voice traffic now carried across the data network to branches, if there’s an issue with that branch, the calls are still delivered to the centralised platform, so your customer is always looked after.

We’re a carrier-agnostic telco: we deliver SIP Trunking via diverse carrier data accesses, providing options for highly available and resilient solutions backed by Service Level Guarantees. This can be to multiple sites or a single site with diverse lead-ins. SIP delivers smart solutions to manage calls at each site to your business needs.


SIP voice is delivered by Ethernet, with channels determined by bandwidth available. You can stop investing in more line cards when you reach 30 channels – Ethernet scales on demand to meet channel requirements.

Unified communications to boost productivity

The idea of accessibility wherever you are through unified communications (UC) introduces the concept of ‘presence’ to the IT world.

UC clients are ‘present’ whether they’re on their desk phone, a PC, mobile or tablet. This comes with access to chat, file and screen sharing functions. You also get ‘click to dial’ voice call routing – the call is automatically directed to where you are, so there’s no need to look up multiple numbers.

A workforce on the move

Your phone number travels with you, so you can appear ‘at work’ to customers and colleagues wherever you are. Your mobile device can use either the ‘data’ WiFi network or 4G mobile network for voice calls.

If you’re overseas and connected via WiFi, you’re mobile is charged as if you’re on a cellular network, so you avoid global roaming charges. As 4G mobile networks evolve, they’ll also become IP based and move through their own evolutionary cycle as all voice communication shifts to data networks.

What does this mean for your business?

Use case 1: You already have an ISDN PBX

If you’ve sunk investment into PBX hardware and a maintenance contract, we can help.

We deliver a SIP-Ready ISDN service. It looks and feels like ISDN to your PBX, but is converted to SIP via a local IAD (Integrated Access Device).

You get all the benefits of SIP voice flexibility, and we’re there to help when you’re ready to change.

Use case 2: Your PBX is SIP capable

If your local PBX is SIP-ready, we deliver a SIP Trunking service to your local site and migrate current numbers to the new service.

Our porting team handles the transition, reducing risk and minimising downtime.

Use case 3: Your network or technology lifecycle review is due

Your current environment may be a blend of PSTN / ISDN 2/ ISDN 30 voice technologies, or due for a technology review. Either way, if the data network is struggling to keep up with the bandwidth demands of today’s applications, it’s time to refresh your technology.

Switch spend so voice can be carried across the data network. Connecting to our Tier 3 Data Centres provides options to:

  • host your physical PBX
  • virtualise your PBX in our state-of-the-art cloud environment
  • take advantage of our hosted-PBX Unified Communications as a Service (UCaaS).

From change comes opportunity

Smart businesses will use the phasing out of ISDN as an opportunity. Future-proof your business, reduce your costs and simplify your voice services. Engage your staff with simpler systems, and create better customer solutions. That’s a win for your business.