The first thing to do when you need to renew your PRIs is re-evaluate your phone system. Unless you’re in a financial bind where you can’t replace your PRIs… You need to get rid of them immediately!
The PSTN or Public Switched Telephone Network was once fully analog, switching voice traffic as electrical signal over copper wires. Today the PSTN is mainly SIP based and most PRIs are deployed as SIP then converted to a PRI using an IAD or Integrated Access Device like an Adtran, Ciena, or Cisco.
Phone systems that needed to be expanded in the past had to use T1 cards and often were connected to the greater copper network. That copper network is being retired. Copper erodes over time and has less capacity than fiber. A fiber the size of the four wires that compose a standard POTS line can handle the voice traffic of a whole county.
Much of the functionality that companies relied on from their phone system has been moved into the functionality at the POP. 5ESS switches are being retired quickly and swapped out for higher functionality switches like Broadsoft and Asterisk based systems that are capable of deploying dial tone as well as a hosted handset… if you’re old school think of Centrex.
Advanced functionality can be managed by an internal switch like a Panasonic or Avaya, if a company had advanced needs. Most often what we see companies taking advantage of is the ability to forward calls to cell phones should an outage occur or an employee work remote or leave his/her desk. Conference calls are typically preplanned and rarely do I need to conference someone into a call and not have the capacity.
SIP trunks or a fully hosted system are your best bet if you’re still terminating to a PRI or POTS lines. There are further questions to consider from there if you’re not sure which of the two to go with. Learn more about voice services, voice equipment, and unified communications here. Or feel free to contact us for further consultation.