SIP vs. PRI

Definition:PRI - Primary Rate Interface.SIP - Session Initiation Protocol.

Allocation:PRI is sold per circuit. Each circuit provides 23 channels or

call paths.SIP is sold per call path.

Infrastructure:PRI is part of the Public Switched Telephone Network

(PSTN). SIP is Voice over IP and is delivered over an internet

connection.

Phone Numbers: PRI utilizes Direct Inward Dialing (DID) phone numbers

that can be purchased in blocks of 20 and are local to the area the service is terminated.

SIP utilizes DID but can use local and out of area phone numbers. With SIP, a company located in Philadelphia could utilize Phoenix telephone numbers.

Disaster Recovery: In the event of a natural disaster, SIP DIDs can be rerouted

from one office or call center to call centers or offices untouched by the event.

This can be accomplished more easily and seamlessly than with PRI.

Utilization:Multiple users at a single or a networked location can share

PRI voice channels.SIP trunks can be centrally located and shared company

wide, maximizing economies of scale. This setup is facilitated by the availability of out of area DIDs.

Scalability:PRIs provide 23 channels or voice paths. If a business

requires more than 23, they have to order another PRI, and deployment requires 2 to 3 weeks time.

SIP trunks can be ordered in any increment and implementation can be completed in days, sometimes hours.

Resource Utilization:PRIs are static. When their channels aren’t use, they sit

stagnant.SIP is a dynamic service. When SIP trunks are not in use,

the bandwidth they require is freed up for other uses.

Availability:PRI requires a local loop, provided by a local phone

company or incumbent carrier (ILEC). PRI providers must have agreements in place with ILECs to be able to provide PRI.

SIP only requires an internet connection, so there is a smaller barrier to entry to become a SIP service provider, leading to more competition and lower prices.

Handoff:PRI requires the existence of a T1 card in a PBX or business

phone system.SIP can be engineered to work with any type of phone

system.

Cost:PRIs typically cost between 4 and 5 hundred dollars per

month. The cost is higher for more remote locations that require a longer local loop.

SIP trunks cost between 10 and 20 dollars per month. The service can be made more economical when SIP trunks are consolidated at a company’s head quarters and shared, requiring fewer in number. With SIP there is a cost of the added bandwidth necessary to support the service, but the cost of bandwidth has dropped and should continue to do so.

For More Information:John GelhardCarrierBid Sales DirectorToll free: 888-706-5656 x 701Direct: 609-921-3434Email: johngelhard@carrierbid.com