PRI vs. SIP Trunking
What are the advantages of PRI versus SIP Trunks? 1. Relatively little equipment between the PTSN and the PBX. Less to break or go wrong. 2. Simple to set up. No need for QoS, routing, authentication, etc. Of course if you only know IP, SIP is easier, but if you learn both, ISDN is easier. 3. If compared to SIP over internet, PRI has guaranteed quality. Granted, SIP *can* have just as good (and better) quality, just not guaranteed if done over the internet (it can be guaranteed over a private circuit). 4. Less latency/delay so there is less "talk-over". 5. FAX, high speed modem, TTY, etc, pass-through actually works. (it *can* work over SIP, but Asterisk just isn't quite there yet)
What are the advantages of SIP Trunks versus PRI? 1. Cost - Inexpensive. (at least SIP-over-internet) 2. Easy and quick to scale if you have bandwidth. 3. Great for disaster recovery if using SIP over internet. 4. Very cheap to get "local" numbers from all around the world. 5. If using SIP over internet, easy to compare provider.
