PRI vs SIP Trunking
UCx IP Telephone Systems
What is SIP Trunking?

Simply, it is voice calls made over the internet. (VOIP) With each SIP Trunk you get 25 channels in/or outbound.

What is a PRI?

(Primary Rate Interface) has been around since the 1980’s. It is an interface standard used on an ISDN (Integrated Services Digital Network) to deliver multiple lines of voice and data into a business’s existing PBX via one physical line (a circuit). Most business have their ISDN PRI circuits in the form of a T1. A T1 carries voice and data via 24 channels.

What is the cost savings for using SIP Trunking?

Cost savings using SIP trunking can be very significant. Consider what you pay for your PRI. ( $450-$1000’s per month) ONE SIP TRUNK cost $1.20 per month plus your usage. Outgoing calls with in the US are only .012 cents per minute. Incoming calls are even less. Think about how SKYPE has saved money for people in the residential market. They have a way around the high cost of the PSTN (Public Switched Telephone Network). In a similar way, SIP Trunking is making that savings available for business’s. Learn More




Cost Savings

A SIP channel cost $1.20 per month plus usage. General savings of 20%-50% over PRI

PRI monthly costs can range from several hundred to several thousand dollars per month (depending on usage)


Sip requires no additional hardware

PRI requires circuits to be physically connected and terminated


If an outage occurs, calls can be r

erouted to a mobile phone, other land lines or a PRI

If an outage occurs, backup SIP trunking or PRI can be an option


Additional channels can be added with in hours. 

Installation can take several weeks.


Sip is sold Per Channel (1 SIP trunk has 25 channels) 

PRI is sold per circuit, and each circuit provides 23 voice channels

Remote Extensions

Extensions can be offered as a standard SIP feature

A dedicated circuit is required with a PRI

Call Quality

Call Quality on SIP trunking is high.  If improperly configured or not enough band width -voice quality issues can occur

A PRI has dedicated physical lines so therefore call quality is superior