Making the move from PSTN to SIP trunk: SIP trunking explained
The trusted old Public Switched Telephone Network (PSTN), with its Analog, ISDN BRI, E1 or t1 lines, is to disappear. Telephony is moving from PSTN to much more modern and flexible SIP trunks.
The big telecom providers are fast phasing out the old PSTN functionality, and are moving customers to IP. And so a SIP trunk and a phone system upgrade in the near future is going to be inevitable.
Verizon will phase out ISDN in the U.S. by 2018. In the UK, ISDN lines are down to less than 3 million lines, from 4.7 million lines in 2007 and the trend is accelerating. By 2017 major telcos such as BT, KPN, France Télécom, Deutsche Telekom and Telecom Italia will no longer offer ISDN lines.
As a result Session Initiation Protocol (SIP) trunking has increased by 62 percent in 2015 from the prior year, driven primarily by North America. This guide explains what SIP trunks are, their advantages and how you can make the move.
What are SIP trunks?
SIP trunks are telephone line trunks delivered over IP using the SIP protocol. Using this standard protocol, telecom service (VoIP) providers connect one or more channels to the customer’s PBX. Phone numbers and DIDs are linked to the SIP trunk. In many cases numbers can be ported to the SIP trunk.
Benefits of SIP trunking
But our farewell to the PSTN brings many benefits. SIP trunks deliver:
Selecting the right SIP trunk provider
The next step is to choose a SIP trunk provider who will supply the necessary SIP trunks. A few factors come into play when making this decision:
Upgrading Internet connectivity
Once you have selected your SIP trunk provider, consider a dedicated Internet line for the SIP trunk. Most firewalls are able to handle multiple WAN connections, and, considering the low cost of an Internet line in most places, a separate VoIP connection will be the most reliable way to ensure the quality of your VoIP calls.
However, some SIP trunk providers bundle their service with a dedicated Internet line. This keeps your voice traffic separate from your data traffic. Much will depend on the cost and your network infrastructure. Check that your firewall is up-to-date and will be capable of handling VoIP traffic correctly.
Upgrading the PBX to an IP PBX
Chances are that the trusted old PSTN lines are connected into another trusted old device, the hardware-based PBX. This device its inflexible, difficult to manage and often expensive to maintain. Technically it is possible to buy a gateway that allows the old PBX to talk to the SIP trunks. But why not upgrade to a modern IP PBX and leverage the flexibility and modern features IP telephony can bring. This allows you to take advantage of the cost savings, easy management, and productivity increases with full-scale Unified Communications that an IP PBX offers. You can choose from a hosted PBX, an appliance PBX, or a software-based PBX.
Hosted PBX Vs On-Premise PBX
Many companies are in the dilemma whether they should purchase an On-Premise PBX or a Hosted PBX, the battle of the Hosted PBX Vs the On-Premise PBX begins. It all depends on the size of the company and what they wish to gain from their PBX.
To make a decision, a clear picture of both PBXs should be available. Below are the advantages and disadvantages of a Hosted PBX and an On-Premise PBX.
A TDM (Time Division Multiplexers) PBX is one of the most common types of voice infrastructures as it has been around the longest. A TDM PBX consists of proprietary, self-contained systems as it was designed before contemporary server technology was invented.
Involving a cabinet with numerous different boards that can perform certain functions, for example intercom functionality boards or analog extension boards, the TDM PBX is coming to the end of its life cycle. The TDM PBX boards are only compatible with systems from the same vendor as an overall architecture, locking in its users to use the same vendor for everything.
A TDM PBX requires dedicated staff to be able to manage it as well as extensive maintenance. It is mostly used by companies which have yet to update their network cabling.
The main difference between a TDM PBX and an IP PBX is that an IP PBX uses Internet Protocol to route calls whereas a TDM PBX uses physical switches. Additionally, an IP PBX is scalable, offers no vendor lock-in and can reduce telco costs drastically.