Aswath Weblog

VoIP, PSTN and making calls

Om comments on a recent column by John Dvorak regarding VoIP. I almost share Om’s opinions but for one. Indeed, my reaction is well depicted in the accompanying picture, where Dvorak is closing his ears in apparent disgust. Dvorak’s points are:
1. Incumbents are hindering introduction of VoIP because of their investment in expensive “old phone switches”.
2. Incumbents are rolling out inferior quality DSL to artificially limit VoIP adoption rate
3. 911 (sic, not E911) service is a red herring. It seems the world was OK when he was a kid and dialing the operator was sufficient. (I presume that the car he used to ride in didn’t have front, side airbags, collapsible and shock absorbing hood etc. Will he be content to do the same now, I wonder.) Also did you know that mobile operators are introducing 911 (I presume E911 is meant here as well) service because of the threat of VoIP.
4. The consumers can avoid the regulation quagmire by using VoIP only for on-net calls and use cell phone to reach those that are still enslaved to PSTN.

Om takes issue with points 1, 2 and 4 (he is silent on 3). I have already betrayed my reaction to point 3. But there is something in point 4 that I want to expand on. Here I am making an assumption that many of us will have access to more than one communication: wireline telephone, wireless telephone and VoIP device; and we will be connected to different set of networks at different time. Recognizing this reality, “VoIP ATA” should have multiple interfaces: FXO for wireline PSTN, “Cellsocket” like adaptor and of course basic VoIP adaptor. So when Om wants to contact Andy, he will select Andy’s name from his “buddy list” prompting the ATA to generate a SIP INVITE which will be intercepted by Andy’s SIP redirect server and it will instruct Om of the current point of contact. On the other hand, if he wants to contact his mother, he would have programmed the “buddy list” to dial out using one of the PSTN interfaces. This ATA can also do further optimization by using some selection logic for using the specific PSTN interface. So, it is possible to adapt the technology to human behavior if we move away from 12+1 button phone interface (my predictable refrain).