PRI/SIP Trunk

PRI/SIP Trunk

SIP/PRI

A PRI trunk uses the Primary Rate Interface standard to transmit as many as 23 voice channels over a single copper telephone wire. A PRI trunk provides a physical connection to the PSTN and uses a circuit-switched model to make connections.
A SIP trunk uses Session Initiation Protocol to transmit data and can scale easily to accommodate as many voice and data channels as an organization requires. A SIP trunk provides a virtual connection to the PSTN and transmits voice calls as data, using a packet-switched model to make connections.

When considering an enterprise phone system, the selection often comes down to a choice between a PRI and SIP system. But what is the difference between PRI and SIP trunk options, and what advantages and disadvantages to both systems present? Here’s a short overview on “What is the difference between PRI and SIP trunk?” that provides some detail.

What is the difference between PRI and SIP trunk?

A Primary Rate Interface system, or PRI trunk, provides a physical connection to the Public Switched Telephone Network (PSTN), while a SIP trunk offers a virtual connection to the PSTN. A PRI trunk is a single line, usually a T-1 connection in North America, with 23 voice channels transmitted as electrical signals over copper wire, using a circuit-switched model for making voice connections. A SIP trunk sends voice calls as data over an existing ethernet or fiber connection. A SIP trunk supports Voiceover Internet Protocol (VoIP) telephony and uses a packet switching model for making connections.

What is the difference between PRI and SIP trunk for scalability?

Because each PRI trunk line provides 23 channels, scaling up requires a business to order additional PRI trunk lines which may take 2 to 3 weeks to deploy. A SIP trunk can be ordered with any number of increments and can be deployed in days or hours, providing a more flexible telephony technology.

What is the difference between PRI and SIP trunk in security?

A PRI trunk is often thought to be more secure than a SIP trunk, since the latter may be vulnerable to security risks when running VoIP over public Internet connectivity. However, with adequate network security, a SIP trunk may be just as or more secure than a PRI trunk.

What is the difference between PRI and SIP trunk for QoS?

Because a PRI trunk uses a dedicated connection for voice transmission, it tends to offer higher Quality of Service than a SIP trunk, which often must compete for bandwidth with other data sources.

What is the difference between PRI and SIP trunk in costs?
The cost of a SIP trunk may be as much as 30 to 40% cheaper than the cost of a PRI trunk.

What is the difference between PRI and SIP trunk in terms of reliability?

While PRI is considered to be highly reliable, the copper wires in a PRI trunk may be damaged by weather, vandalism and aging infrastructure. A SIP trunk offers greater redundancy and is very resistant to weather and other types of damage, especially when provided as part of a fiber-optic connectivity.

What is the difference between PRI and SIP trunk with Spectrum Enterprise?

As a leading provider of fiber solutions to America’s largest businesses, Spectrum Enterprise offers both PRI trunk and SIP trunk solutions, with interoperable and feature-rich support for fiber solutions for premise-based phone systems. Spectrum Enterprise voice technology provides next-generation communications solutions with superior call quality and cost advantages, along with collaboration features to keep employees and clients connected.

What is the Difference Between PRI and SIP Trunking?

The difference between PRI and SIP Trunking is that PRI requires a physical wired connection to the digital PSTN to allow for 23 simultaneous communication channels (lines), while SIP Trunking virtually connects to the IP network to allow for unlimited, VoIP-based communication channels.

As a voice technology, PRI has been used since the 1980s. It is an interface standard deployed on Integrated Services Digital Network (ISDN) to deliver voice and data channels into an enterprise’s existing PBX via a physical circuit. It is a high-capacity service delivered on E1 or T1 trunk lines between the telecom service provider and the business location. In India, a single PRI E1 line has 32 channels, of which two are used for signalling and 30 for voice, video and data-based communication.

With its physical hardware, PRI requires the support of service provider for its deployment, upgrades and troubleshooting.