SIP trunking offers substantial cost benefits over PRI (Primary Rate Interface). The flexibility of SIP also means that business growth opportunities, features, presence and integration aren't precluded by dead technology. PRI is dead and was dead almost from its start. "It's some dumb network (ISDN)" is what people in the industry call it.
The PRI is a glorified T1, and the development of ISDN (Integrated Services Digital Network) was primarily for the carrier's benefit. Having used PRI and BRI (Basic Rate Interface) since their inception in the U.S., there's no looking back. Let me explain.
No one can rationally dismiss the cost benefits and savings of SIP trunks over anything that traditional carriers have to offer. I can buy direct inward dialing (DID) numbers when and where I need them in order to expand my business presence without having a local office in that city. The lower cost of doing business with SIP trunks has added benefits: flexible bandwidth and bandwidth management for all my communications needs. Technically speaking, PRIs and T1s are just noisy copper pairs that carry premium price tags.
Unless you live in Australia or some South Pacific locations, BRI isn't faring against SIP trunks since 128 Kbps is no match for the unbridled bandwidth that consumers and businesses demand. What happens when the PRI/BRI or T1 goes down? Businesses have multiple Internet connections that serve as failover -- yet another advantage of SIP trunks. Organizations should leverage bandwidth and harden network infrastructures (if they aren't already) in preparation for kicking out PRI. PRI only profits the carriers.
This was first published in February 2013