December 18, 2015

SIP Trunking versus ISDN: Which Should You Choose?

By Admin

SIP Trunking is quickly rising in popularity with businesses around the world. This is due to the benefits offered by the technology, the most obvious of which lie in cost savings. Some businesses may be reluctant to change when it comes to telecoms, so let’s have a look at why they should choose SIP Trunking over ISDN.

ISDN (Integrated Services Digital Network) describes a set of standards that support voice and data transmission over the traditional copper network. It is a digital technology that offers advantages over analogue PSTN which include:

  • Guaranteed data transfer rate (64kbps for every connection)
  • Supports channel bonding
  • Can handle voice and data
  • Offers more features than analogue telephony

With ISDN, businesses are required to pay separately for voice and data services.

SIP Trunking is an application layer protocol that is based on IP, it’s a newer technology than ISDN and allows a business to carry both voice and data on the same channel. A business can choose to have SIP Trunking alongside its existing infrastructure with the use of an IP gateway, or it can add it to its existing IP PBX.

So SIP Trunking is a more modern telephony solution that uses the internet to deliver voice and data through a single pipeline. ISDN on the other hand, uses the traditional copper telephone network to deliver voice and data.

Making a Choice

When it comes to which is better for businesses, there’s little doubt that SIP Trunking is the clear winner. Not only is it a more modern solution, but it also saves businesses a lot of cash both in its installation and ongoing maintenance. SIP Trunking is a virtual product. Unlike ISDN, no special equipment will need to be added in order for a business to use it.

The reality is that whilst ISDN does allow for data to be carried over the network, it doesn’t do this efficiently or cost effectively, whilst SIP Trunking does. It’s fair to say that we’re likely to see the death of ISDN as the telephony solution of choice, as more and more businesses turn to IP telephony (if we haven’t already). ISDN is quickly becoming outdated and can be more accurately thought of as a legacy solution.

Making the Switch

The benefits of SIP Trunking over ISDN are plentiful. As SIP is a virtual product, to begin with it requires no additional hardware to be purchased in order to install it. The existing PBX can usually support SIP and will need to be configured in the first instance. When it comes to ongoing maintenance costs, there quite simply are none, so businesses can save on their telephony year-on-year once they’ve made the switch.

No capital expenditure is required to install SIP Trunking, whereas the installation and maintenance of an ISDN system can be costly. Further, SIP Trunking can be purchased line by line — rather than in a block of 23 as is required with PSTN. This means that the customer is only ever paying for what they use and allows businesses to save costs when it comes to redundant lines.

So in the first instance, there are cost benefits that can save businesses up to 90% of their traditional solution, depending on the needs of the company.

Advantages Over ISDN

Cost will of course be a huge incentive to any business to make the switch to SIP Trunking. But it’s not just the initial cost saving that’s attractive, businesses should also consider the following.

  • Lower call rates — generally SIP offers lower long distance and international call rates than ISDN.
  • Convergence — rather than pay out for voice and data services, SIP Trunking allows businesses to consolidate these over a common IP network.
  • Scalability — it’s simple to scale both up and down with SIP Trunking so that the business only ever pays for what it needs.
  • Enables further services — such as unified communications (separate service) so that businesses can further streamline communications and offer an increased level of service to their own customers.
  • Disaster recovery — as SIP Trunking isn’t reliant on the traditional telephone network, it suffers from less downtime, meaning that the business is more productive.

There are plenty of benefits to using SIP Trunking and it’s clear why the technology is being adopted by so many businesses so quickly. Many are now beginning to work SIP Trunking into their overall LAN and WAN strategies to gain further benefits from it too. ISDN in its day was a great alternative to analogue systems, but it’s now outdated and expensive.