PRI is sold per circuit. Each circuit provides 23 channels or
SIP is sold per call path.
PRI is part of the Public Switched Telephone Network
SIP is Voice over IP and is delivered over an internet
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.
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.
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.
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.
PRIs are static. When their channels aren’t use, they sit
SIP is a dynamic service. When SIP trunks are not in
use, the bandwidth they require is freed up for other uses.
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
PRI requires the existence of a T1 card in a PBX or business
SIP can be engineered to work with any type of phone
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
For More Information:
CarrierBid Sales Director
Toll free: 888-706-5656 x 701