Upgrade Your Traditional PBX Phone System with SIP Trunking

Upgrade Your Traditional PBX Phone System with SIP Trunking

SIP trunking is a convenient solution for businesses reluctant to upgrade their telephony hardware related to a PBX phone system. As phone systems of the past start to become obsolete due to the rapid development of the best phone system software technology, businesses that have invested many resources in their PBX telephone system may feel like money is down the drain. 

Instead of completely discarding your existing phone system instead of voice over internet protocol telephony (VoIP) or video conferencing just yet, SIP trunking might be able to give your business phone system a few more years of use before considering an upgrade. Let’s explore the features and benefits of SIP trunking telephone systems to understand if SIP trunking is the right move for your business. 

What Does SIP Trunking Mean?

Session Initiation Protocol (SIP) trunking acts as a connection between voice over internet protocol (VoIP) type communication with a traditional PSTN network. It is an application layer protocol connecting audio and video calls between two endpoint devices. SIP trunking creates, manages, and ends sessions with different participant IP networks. 

SIP trunking is the same as analog phone lines but virtual. SIP trunking allows users to connect to multiple lines within a network and can even allow a user to make outbound calls without restrictions on the number of simultaneous calls. 

SIP trunking providers allow scalable options for businesses to connect their PBX system to the external world. 

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What are the Benefits of SIP Trunking?

SIP trunking for your PBX system allows the following benefits for your business:


Although SIP trunking functions over an internet connection and can seem unreliable during a power or internet outage, that isn’t the case. SIP trunking allows for calls received to be rerouted to your other devices automatically to assure business continuity despite the status of your power connection. 

Cost Savings

With the VoIP capabilities using SIP trunking, your phone system now has access to, thanks to SIP trunking, and the cost of your phone bill will be much more manageable for your business. Since the number of users breaks down the cost savings of SIP trunking, your company phone bills are more likely to be consistent and predictable than PBX phone systems with traditional PTSN lines. 


Traditional phone systems can be expensive to upgrade as your business grows. While working over IP networks, SIP trunking allows your business to rely on its internet bandwidth allocation without worrying about additional charges. SIP trunking allows your business to add or remove users based on current requirements by consolidating voice and data communication into one solution. You can even scale your call center globally since you are no longer limited to a local network provider. 

Increased Security

SIP trunking providers go to great lengths to ensure their product is secure. SIP trunks are monitored for unusual activity and would alert you whenever there is suspicious activity within your phone system. 

Ability to Use Existing Phone Systems

Since SIP trunking can exist with your existing phone system to give it a new leg of life, you do not need to discard and upgrade the current system. SIP trunking also allows your office to become mobile during the recent uncertain times. 

What Is SIP Trunking in PBX?

Many companies invested in TDM PBX in 1999 and still have years of life left in the hardware but are dying to upgrade to a cheaper SIP trunking solution. These companies are now wondering if they can salvage their TDM investment but still add SIP trunking to their existing infrastructure. 

It is possible to use your legacy TDM PBX solution alongside SIP trunking while still maintaining the benefits and features of both.

SIP trunking capabilities, however, are, rest on the fact that your PBX is SIP-ready. If by chance, your PBX is not SIP-ready as you are running an essential system or traditional analog, then you will need to install an integrated access device.

SIP trunking is surprisingly easy to install and configure but will give you a few more years of use from your TDM before you switch entirely to a SIP trunking solution.

The process will be pretty simple if you have available TDM trunk ports…but you most likely do not. To route a new SIP trunking solution through your TDM, you need to make a “drop and insert” style installation by placing a media gateway into the TDM trunk circuit. You will need to insert the media gateway between the TDM and PBX so that one side of the gateway faces the TDM and the other side the PBX. The SIP trunking gateway will go unnoticed as it simply routes traffic from one appliance to another, but it is an essential ingredient.

Now you need to set up your SIP trunking solution and terminate it with the TDM on the media gateway you have just installed. When you have completed this circuit, you will have both the TDM and SIP terminating on the newly installed gateway. Routing tables will now be cleverly shuffling the calls between the courses.

This new solution should also provide a failsafe in that if the TDM or SIP fails, the service will roll over entirely to the service still running. If both the TDM and SIP fail, then you are stuck.

How Much Does SIP Trunking Cost?

The integrated SIP Trunking solution mustn't require too much outlay. The initial costs to integrate your existing TDM PBX with a SIP trunking solution are minimal. SIP trunking costs may vary depending on your business’s requirements. 

Many SIP trunking providers charge a standard fee for unlimited local and long-distance calls per user. Each SIP trunking line can handle as many calls as your bandwidth allocation allows, so the number of lines you can take depends on your bandwidth availability for SIP trunking. Additional channels can be added to your plan depending on your business’s needs. Then you have the cost of the SIP trunk implementation, which will vary depending on the phone systems solution you choose.

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