Over the last few years I’ve started to see very little differences between email and phone systems and I was wondering if you see a trend going in this direction as well.
Today: Email communication between 2 user is all done via DNS: MX (mail exchange) Records. Phone calls are done between 2 users via Telco providers, and then if VoIP: IP/SIP Peering.
Tomorrow: I expect to see a trend where an email address, is also a VoIP Extension, so email@example.com is routed via SIP, we alreay do this on closed, internal VoIP Systems; but what about communicating with external peers the way email works. We’ll need Spam filtering I’m sure, as well as excellent NAT Control (unless we go IPv6!!!). An equivalent to SPF (rfc4408), to solve the Caller ID Spoofing problem, options for TLS, and a way to Route the call. We use SRV(rfc3263) records now but for many those are confusing and rarely used except for (again) controlled environments or MS Lync/Skype Out. Maybe it’s time for a new protocol, RTX Records (real-time exchanger) is my thought. It would be RR just like MX (rfc1035), but for Voice/Video and would need a solid baseline, SMTP is established, SIP still offers a plethora of media protocols and transports, and the ability to fall-back is required as well
Early Adoption, this above is a long time away I’m sure, but what about a service that slows direct sip routing by phone number, a 3rd party service (similar to SIPStation) that provides no outbound calling, only negotiates connections between parties with confirmed phone numbers. Since there’s no toll, no phone service, and all users must pass a ‘qualify sip’ test to ensure interoperability, the service would simply marry up an IP Address/Phone numbers with phone numbers, and add/lookup routes for those numbers to see if direct-IP call is possible, if it is, route via that direct-IP, if not, fail back to 3rd party trunks.