SIP Trunking

Making the move from PSTN to SIP trunking:

The Public Switched Telephone Network (PSTN), with Analog, ISDN BRI, E1 or t1 lines, will disappear and be replaced by SIP as the main method to transport voice. All the main teleco providers are all phasing out traditional PSTN functionality and are moving customers to IP. SIP trunk and phone system upgrades are going to be inevitable.

Global & Local trends are:

By 2018 Verizon will phase out ISDN in the U.S. and by 2017 BT, France Télécom, Deutsche Telekom and Telecom Italia will no longer offer ISDN lines. As a result (SIP) trunking has increased and is replacing most forms of connectivity. On the local front Telkom SA has embarked on a massive fibre deployment drive and are installing new SIP enabled exchanges all across the country.

The benefits of SIP trunking

Lower monthly Line & DID Rental – The monthly fee to have a number of lines installed at your office drops significantly with SIP trunks and DIDs cost a lot less. Lower call charges – There are many SIP trunk providers and competition has driven down call charges significantly. Some SIP trunks even come with unlimited calling. Better customer service – It is quick and easy to add numbers to your SIP trunk and terminate them on your IP PBX, you can offer customers more options at a significantly lower cost. Move office and keep the same number – SIP trunks are not bound to a location, so it’s easy to move office without having to change your stationary or inform your customers. There is no longer any need to pay to forward phone calls to the new office. Eliminate VoIP Gateways – SIP trunks will eliminate the need to buy and manage VoIP Gateways. All phone calls come in via IP. No extra conversion often means better quality. Modern IP PBX / Unified Communications solutions will give customers increased productivity, mobility and boost sales. Connecting an IP PBX to SIP trunks is much easier than via the PSTN. Flexibility – It is easy to add channels to your SIP trunk to cope with increased calls. A simple phone call will allow you to add channels, and often this can be done immediately. Compare that to the delay in having additional lines installed and then having to upgrade your old PBX to handle more lines. Correct number of channels – With SIP trunks, you can easily choose the correct number of channels that you need. Using ISDN/T1, you often have to choose to add either 10 or 30 lines. This usually means you end up with expensive extra capacity.

Selecting the right SIP trunk provider

A few factors come into play when making this decision. At Goldtel we take the following very seriously and have multiple levels of security in place. Factors to take note of are: Security – As SIP trunks are exposed to the Internet, it is very important that the SIP trunk has a well secured network and an anti-fraud system in place. The anti-fraud system must monitor the system and provide protection against call fraud. Own network – Does the SIP trunk provider run its own network or is it a rebranded service? There are many providers out there reselling SIP trunks from other providers. At Goldtel we own our own network and are an accredited ECNS license holder. Competitive Cost – Costs vary widely between services. Some vendors will overcharge for SIP trunks. Look for competitive rates, but ensure that you are getting a business quality SIP trunk service. Be cost conscious, but expect to pay a bit more for business class service. Number Porting – Can the provider port your phone numbers? Ensure that you choose a provider who can port all the existing numbers – not all providers are able to do this for all regions.

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. 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 is 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.

SIP trunks


SIP trunks from 1 to 8 voice channels including one 087 number with hunting across all lines ordered. This is a monthly to month recurring cost with no long term contracts needed for only R39.00 per line excluding VAT



SIP trunks from 9 to 16 voice channels, including one 087 number with hunting across all lines ordered. This is a month-to-month recurring cost with no long-term contracts needed for only R36.00 per line excluding VAT.



SIP trunks from 17 to 29 voice channels including one 087 number with hunting across all lines ordered. This is a month-to-month recurring cost with no long-term contracts needed for only R33.00 per line excluding VAT.



SIP trunks from 30+ voice channels including one 087 number with hunting across all lines ordered. This is a month-to-month recurring cost with no long-term contracts needed for only R23.00 per line excluding VAT BizVoice-8.



Additional 087 number that can be added to any of the BizVoice packages if more than one number is required. The 087 number can be used on its own as a dedicated trigger number or can be linked to any traditional type ported number. For example, if a customer has an 011, 012 or 021 number and would like to keep this number, it can be ported and linked to a new 087 number issued by Goldtel. That means a customer can phone either the ported or 087 number and still reach you. The cost per additional 087 number is available for only R32.00 per number excluding VAT.

We can also now offer Geographic numbers like 010, 044, 031, 021, etc.


For porting costs please contact Goldtel or you authorized dealer.

Value Add Packages


This package offers a customer the option to rent hardware instead of purchasing it to activate SIP trunks. This package includes: 4 x SIP trunks, 1 x 087 number with hunting, 1 x ADSL router and 1 x 4-port FXS gateway for R770.97 for the first month and R371.00 per month after the first month. This rental option requires a user to sign a 12-month agreement. This package can be used to connect any traditional PBX to the VoIP platform using xDSL as a connectivity method.


Hardware Only Rental Packages


This rental package consists of 1 x xDSL router which can be used on any DSL service. Month-to-month xDSL services requires a customer to purchase their own router. Using this option allows a customer to rent the router instead of purchasing it at R135.00 a month excluding VAT.


Hardware Only Rental Packages


This rental package consists of 1 x xDSL router, 1 x 4-port FXS gateway at R19267.00 a month excluding VAT. This can be used on any DSL service and can connect to any analogue lines on a traditional PBX. This does not include the line rental services and is hardware only.

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