Compare Pri Vs T1
PRI is the acronym for Primary Rate Interface. It is a switched service delivered over a T1 connection. When a person says If that thy want to order a PRI to some location X, they mean that they are requesting for connection to a ISDN protocol (Telco switch) delivered to that location X through a DS1 rate (T1) circuit. And now, if that person says that they want to order a T1 to that very same location X then that would really not be sufficient information. In this case, various questions may arise like - a) A T1 from where to where? b) A T1 for what?
One clear difference between t1 and PRI is that a T1 is just a 24 channel circuit. One can use T1 for multiple purposes whereas a PRI is a protocol. It uses the 24th channel for controlling the usage and working of other 23 channels. That is, a T1 has 24 channels using 8K for signaling and 56K for data. A PRI has 24 channels amongst which 23 are used for data and the 24th is used for signaling.
Apart from the caller ID, there is one other big difference between T-1 and PRI. That is, in case of a T-1 you need to devote all the Channels to a different type of circuits. So, say if you have DID and Tie lines coming via one same DID then you have to dedicate some certain channels to these circuits. If you had a PRI here, different type circuits can be used with any of the 23 channels. The D channels have the ability to translate the type of circuit that is being used by the B channels.
In a nutshell, PRI is a different protocol. It must be used with the voice services over the T1 line. While, a t1 line can also be used for voice services but without making use of the PRI protocol and by using dissimilar equipments at the other end for getting the dial tone.
If you compare PRI vs. T1, you can see some of the features that are there in PRI but not in T1. For example, any business that wants to track phone calls and thus improve its customer service will prefer Caller ID or ANI (Automatic Number Identification). Most of the current trend's CRM (Customer Relation Management) software is making use of the caller ID information for displaying the customer's record on the PC even before you get to answer the phone. PRI has the ability to meet this functionality by sending both the Caller ID and DID to your phone system. Now comparing ISDN PRI over T1 - ISDN PRI has 23 B channels. The 24th channel carries the data link. This 24th channel is a 1D channel which a PBX deals with while a T1 uses all of the available 24 channels and connects to the router.
When it comes to T1 PRI pricing, the PRI costs are more per month and it will vary from one carrier to another & one state to another. Some people find T1-PRI to be a lot cheaper per month because that is the rate at which the carriers are selling in their areas. In case of PRI, all local copper lines can be eliminated because a PRI can take local calling as well including E-911 calls. However, a T-1 does not take local traffic all the time. Also, when ever it does, you may have to dial 10 digits or have the switch insert the NNX. Choosing PRI over T1 or ISDN PRI over T1 is totally business dependent.