Hosted PBX Vs SIP trunking – A detailed comparison

Hosted PBX Vs SIP trunking

SIP trunking and Hosted PBX are two of the most common IP protocol communication systems in businesses today. Which is better suited for your organization?

Communication is a key functionality in business operations, and requires efficiency and security. Hosted PBX and SIP trunking are two of the options that are considered by businesses in this function. Although they seek to fill the same gap in an organization, they do so with very different approaches. The major difference between the two being that hosted PBX works by routing calls through a cloud server that is hosted by the service provider, while SIP trunking requires potential users to buy, install and maintain their own servers at the premises. This is the base line for most of the differences between the two, which should be carefully analysed by a potential user in determining which of the two they would go with.

What are the differences between Hosted PBX and SIP trunking?

Hosted PBX
Handling of maintenance
By the service provider
By your in house staff
Call quality
Great for a small number of users
Great for a large number of users
Dependent on provider’s own security standards

Hosted PBX Vs SIP trunking- How do they compare?


This is one of the most critical matters that an organization considers before implementing a new system. Hosted PBX is cost friendly because the service provider takes on the burden of hosting the actual system servers. This leaves the organisation with a smaller financial burden of acquiring the IP phones, routers and a reliable business-grade internet subscription. On the other hand, SIP trunking is designed to be solely controlled by the organization, hence they bear the burden of not only buying the actual server and accessories, but also having a qualified IT team on retainer to man the system in addition to paying for the actual trunking and a separate internet subscription that is to be dedicated to the SIP trunking system. Therefore, Hosted PBX is far cheaper to install and maintain than SIP trunking.


Hosted PBX is designed, as its name suggests, to be hosted and maintained by the service provider. The provider takes care of the server maintenance and the software updates itself, offering a dedicated set of staff that will cover any outages or updates that may come up in the time of contract. This leaves the organisation that has acquired the hosted PBX system with the miscellaneous and simple tasks of changing features and adding users in line with their needs. In the case of SIP trunking, the system is fully hosted by the user and as such, the maintenance is also their responsibility in its totality. This will necessitate the hiring of a dedicated and qualified IT staff to do any system maintenance and updates or employing an external maintenance staff to do the same. This makes SIP trunking more expensive and time consuming to maintain than PBX hosting.

Access flexibility

This is another factor that is tied into the hosted nature of the servers in each case. SIP servers are hosted at the premises of the user and as such are configured to cater to users within a certain proximity to the building in question. This implies that a user, even from the same organization, cannot access the system if they are out of range from the servers since all the phones are on the same singular network. Remote PBX works in a way that allows data to be stored on the cloud of the service provider, since the provider services more than one user. This allows anyone in the firm to use the service on a variety of devices and from a wide range of locations, giving hosted PBX a wider access flexibility range than SIP trunking.


The on-site design of SIP trunking allow for limited scaling depending on the company’s capacity to purchase more equipment and channels in order to cover its additional users and required capacity.  Hosted PBX on the other hand, gives a simpler scaling option, since the host is responsible for the main servers. Therefore, the user would only need to use a web browser and minimal IT skills to configure to the system and get the equipment for use, like IP phones for the additional users. This system makes scalability easy to achieve and implement for hosted PBX system compared to the work that would be required to increase the capacity of an SIP trunking system.

Hosted PBX Vs SIP trunking – A comparison review

Hosted PBX

Hosted PBX Vs SIP trunking

A hosted PBX (Private Branch Exchange) is a PBX system that is designed to allow for the traditional PBX functionalities like voicemail and automated call distribution without placing the burden of ownership, maintenance or security of the equipment for use on the user. It works by having the servers located at the service provider’s location. This is a third party in the end to end user communications, who is responsible for the security of the data and maintenance of the actual servers. The hosted PBX system routes calls to various extensions while simultaneously allowing the VoIP provider to maintain all the software and equipment.


  • It is highly flexible
  • It is easily scalable, depending on the vendor
  • It requires minimal on site equipment to operate
  • The user can have add on services like mobility features and conferencing
  • It includes standard PBX services like call records,, conference calls and voicemail
  • It has the potential for cost savings when bundled with unified business communication systems
  • It does not require power of on-site equipment since it is hosted on the server cloud


  • A high degree of control is maintained by the service provider
  • Its add on services and vendor features offerings vary
  • Its quality of service is dependent on the consistency of the user’s connection to the service that is hosted by the vendor

SIP trunking

Hosted PBX Vs SIP trunking

SIP trunking makes use of the IP protocols to connect a phone call in a given network to the PTSN (Public switched Telephone Network). This process replaces the traditional phone trunk like an analogue line or PRI interface. It involves replacing traditional phone lines with VoIP usage to transmit voice as data via the internet, allowing it to combine VoIP protocol with other streaming services. Installation of an SIP trunking system would require the organization to purchase and install the communication servers, in addition to having a specialized IT team available for maintenance, troubleshooting and updates.


  • It has the potential to save on costs by improving cost efficiency
  • It is possible to have quick addition of added call appearances without waiting for the installation of additional circuits
  • It works by leveraging the user IP network and turning voice into an application on this network
  • It allows for easy and quick routing of call appearances to other sites


  • It is heavily dependent on bandwidth to facilitate its quality of service due to its multimedia transmissions
  • It uses fairly new technology which makes troubleshooting and finding qualified personnel challenging and expensive
  • It has a high initial cost due to the requirement of new equipment and the disposal of old one


Hosted PBX and SIP trunking both have areas where they are best suited. Hosted PBX is cheaper to install and easy to scale, while leaving the task of security and management to the service provider, which may be a relief for certain users, or a security issue for others. SIP trunking is a system that is designed to be independent, making the data in the system the sole responsibility of the user and limiting the user’s proximity from the actual servers. This makes its data more secure, but makes the process of installation and maintenance more time consuming and expensive.

Verdict- So which is better, Hosted PBX or SIP trunking?

SIP trunking is the better pick and is becoming more commonly used. This is because of its superior quality of service, efficiency in operation, security and flexibility as it pertains to medium to large scale offices and other enterprises. It is also gaining popularity because although it requires a high investment, it gives complete ownership and control of the system to its users.


How does VoIP and SIP trunking differ?

The main difference between the two is in their capabilities. VoIP is limited to the transfer of voice data, while SIP trunking can transfer packets of data in different forms of multimedia. These multimedia forms could be video, text or audio.

How many calls can a SIP trunk handle?

SIP trunking follows the 50% rule. For example, if there are 10 people in a given work environment that uses SIP trunking, then only 5 of them can be on current calls, with the use of their 5 trunks at a given time.

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Mathew Blake
Hi my name is Mathew Blake. My love for technology stemmed from a curiosity and fascination is small gadgets ever since I could remember. The Globe is a hotbed for rapidly advancing technology that has brought us a multiple gadgets, appliances and devices and I am here for it. is a blog that is very enjoy writing and researching for. My passion for tech led me to specialize in several technology-related fields, the main being IT. As an IT specialist, my main job is to cater to technical needs in many businesses. I enjoy working all tech related- fields especially ones that allow me to interact with the consumer.


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