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Can I change my lines to SIP trunks?

With the forthcoming PSTN switch off, many businesses are looking for a way to future-proof their phone systems. Many have already opted for SIP trunks in replacement of traditional phone lines.

If you are planning to join the hundreds of other organisations in the move away from a landline phone solution, you may be wondering whether SIP trunking is suitable. We outline what considerations you need to make, as well as the benefits of internet-based telephony in a business environment.

What is SIP trunking?

In layman’s terms, SIP trunks enable a virtual connection between you and your ITSP (internet telephony service provider) via an internet connection.

As a cloud-based phone solution, SIP trunking is commonly confused with VoIP. Whilst the two solutions leverage similar technologies, they are not the same. SIP is an enabler protocol for IP telephony solutions, meaning that most (but not all) VoIP systems use SIP trunking in order to establish a connection.

Whilst VoIP can only be used to carry voice calls, SIP has the capability to transfer both audio and multimedia data, allowing for both voice and video calls.

SIP trunks require sufficient broadband connection

Can your business switch to SIP?

In theory, all businesses can and should make the switch from traditional landline solutions to SIP trunking.

SIP compatibility will primarily depend on the reliability and quality of your internet connection. If your connection is unreliable, or you find that your bandwidth is not capable of handling multiple users simultaneously, certain SIP functionalities – such as video calling – may be impossible.

A video call with a client cutting out unexpectedly or being of inferior quality poses the risk of limiting productivity or creating an unprofessional impression.

You should also consider whether your current broadband package places any caps over your data usage. Whilst VoIP phone calls are unlikely to consume a significant amount of data, transferring multimedia messages or performing video calls could make a dent in your allowance.

If you have found your business broadband to be unreliable, or your current provider places caps over your usage, you would be well advised to find a new ISP before making the switch to SIP.

Benefits of SIP for business

Aside from ensuring that your business remains future proof ahead of the end of PSTN support, SIP trunking is associated with a host of benefits:


SIP connections can be easily scaled to support the ever-changing needs of your business as it grows. Alternatively, if you need to make cutbacks, users can be removed without any trouble.

Cost effective

Mitigating the need for a separate phone and broadband contract, cloud-based phone solutions are typically cheaper than a landline.

Compatible protocol

SIP phone set ups are compatible with a multitude of other solutions, ensuring that if you need to contact a client who utilises an alternative system, communication is not impeded.

Existing number remains

When switching to SIP, most PSTN and ISDN numbers can be ported to the new platform, preventing you from having to change your business phone number.

Cisco 504G VoIP phone system on desk

What to consider before switching to SIP trunks

Before switching to SIP, there are several aspects you must consider, alongside some essential planning.

Broadband quality

As mentioned above, the quality of your broadband is a key factor when switching to SIP. Although most businesses will have invested in a reliable broadband provider, it’s advisable to double check the compatibility of your existing connection before making a decision.

Your business needs

Businesses are often pleased to discover that SIP is a cheaper telephony solution. However, you should always consider your unique business needs before completing the switch.

If your business does not make video calls or send multimedia messages, a simpler VoIP solution may be more suitable for you.

Plan for transitions

With the right know-how and specialist support switching to SIP trunking is relatively straightforward. That being said, detailed planning must be carried out.

It is important to schedule when the switch will take place carefully. In order to avoid unnecessary disruption to your employees and their work, as well as prevent any external communications issues, its recommended that the transition to a SIP solution takes places out of normal work hours.


Ready to make the switch to SIP trunks, future proofing your business and ensuring reliable communications? At Structured Communications we have a wealth of experience in delivering first class cloud-based telephony solutions, such as VoIP and SIP networks to a multitude of businesses. Please get in touch with a member of our team to find out more.