PRI Vs SIP – Which is the better pick?


PRI and SIP are the most common picks for voice data transfer in different sizes and types of organisations. Which one of the two would best suit the needs of yours?

The most important activity in any organisation is communication. This is done between and through different levels of management to ensure that work flows smoothly and that the company reaches its targets. This vital component of organizational structure is the purpose of both PRI and SIP. The major difference between the two is their use of technology; PRI is hardware based, while SIP is based on bandwidth.

This key factor in the functionality of the two allows them to differ in security, call quality, reliability and cost, which makes them suitable for organisations with different requirements and priorities. This detailed comparison should help a potential user to weigh the differences and similarities associated with the two and settle on the one that would best suit their organisation.

What are the differences between PRI and SIP?

Limited by number of phone lines that need to be wired
Limited by bandwidth only
Voice calls are transmitted through the physical circuits
Voice calls are transmitted as data packets through virtual network
Physical connection (Through PRI circuits)
Virtual network connection
Large capacity depending on bandwidth availability
Per circuit
Per channel

PRI Vs SIP- How do they compare?

Call Quality

PRI relies on cables and is heavily hardware based. On the other hand, SIP is based on internet connection and its quality is dependent on the quality and strength of the bandwidth connection. This dependence on internet and bandwidth makes SIP vulnerable to network issues such as packet loss, lag and jitter, which may affect the call quality at the receiving end of the line. Therefore, PRI consistently delivers better call quality than SIP.


This factor is also heavily based on the hardware dependency of PRI compared to the internet reliance of SIP. For as long as the hardware is in good condition, the users in PRI are guaranteed high quality and reliable voice call transmissions. The limitations to this may be damage to wires either because of inevitable wear and tear or due to the effects of the elements, like water or fire. SIP on the other hand, depends on internet connection hence is affected by factors like quality of internet and the reliability of the user’s service provider. PRI is more reliable because the factors that determine its quality of service are easy to control.


SIP uses an internet network to transfer calls which exposes its users to internet risks like hacking. However, it can be made secure with the use of added identification protocols as well as using firewalls. The measures that can be put in place to make an SIP network more secure are seem strenuous compared to the automatic security that PRI offers, being fully hardware, where data travels through copper cables and cannot be accessed by unwanted parties virtually, while in transit. There are risks like interference when using PRI, but this would require any theft of data to be done manually, which is rare and easily traceable. Overall, PRI is more secure than SIP.

Flexibility and scalability

PRI is distributed in circuits, where one circuit supports 24 lines of users. Say you have 25 potential users, you would have to pay for a contract of two circuits just for the one additional user, which is not economical. This factor makes PRI inflexible. SIP on the other hand is very flexible, allowing users to add seasonal or temporary lines for season with high user traffic as well as allowing for user based billing which makes it more economical to scale. Therefore, SIP is more flexible and easier to scale both up and down than PRI.

PRI Vs SIP- A comparison review


PRI, Primary Rate Interfaceis a hardware based voice technology that is commonly used in call circuits for organisations. It is used on a network referred to as ISDN; Integrated Services Digital Network, in order to deliver lines of data and voice into a given business’s PBX through one secure circuit. This interface standard is carried on high quality T1 trunk lines between the end user and Telco-central offices via 24 digital channels. A given circuit supports a maximum of 24 users, and an additional user would require the purchase and installation of another circuit. Its reliance on hardware makes it very reliable and secure, while ensuring high quality of voice calls for the duration that the hardware is in good condition.


  • Voice calls are of high quality
  • It can be made redundant by adding a PRI circuit for failover
  • It relies fully on hardware and not on bandwidth, which is easy to control
  • Voice call data is secure
  • It is well suited for a small business


  • It is expensive to implement and upgrade
  • A given circuit can support a maximum of 24 users
  • It is difficult, expensive and slow to scale


SIP, Session Initiation Protocol, is a phone networking protocol technology that makes use of a closed internet network to deliver voice data. Its trunks are virtual, which alleviates the need for hardware when deploying the system. This is the factor that has made it popular in upcoming businesses because the users do not have to incur the cost of obtaining new hardware devices when initiating the voice data protocol. It allows the internet network to host multiple users, with the number of users supported by a given package being dependent on the requirements of a given organisation. Its main point of weakness would be its susceptibility to internet hacking through which data can be corrupted and phone calls can be overheard. However, this can be overcome by extensive employment of high quality firewalls and other cyber security measures.


  • It is sold on a per-channel basis, based on the user’s demand
  • It is around 30% cheaper than a PRI phone network
  • It has administrative portals that are easy to use for effective management
  • In case of data connectivity loss, it offers failover to mobile phones
  • The providers can offer remote support for multiple site
  • It easily integrates with old PRI phone lines to give a hybrid phone system
  • It can be designed to include mobile designs and rich features
  • It has the capacity for integration with multimedia communication devices and systems


  • It requires internet bandwidth to support its quality of service
  • It is susceptible to hacks and other forms of privacy intrusion


PRI and SIP both have impressive approaches to the flow of communication in an organisation and seek to achieve them in different ways. PRI would be a great pick for a company that either has a small number of users or is heavily concerned with the security of their data. SIP would be the better pick for an origination with a fluctuating number of users and with the ability to take the security measures necessary to protect their data over the network.

Verdict- So which is better, PRI or SIP?

Despite the better call quality and security offered by PRI, SIP would be the better pick because it is easy to scale and the security offered by PRI can be matched by the use of a high quality firewall and its call quality can be guaranteed with the use of a reliable high quality internet service provider.


Is PRI digital or analogue?

PRI is analogue. This is because it is hardware based and uses copper wires over a circuit system to transfer voice data from one user to another.

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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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