Alice is a customer of CP1, a large mobile carrier. Bob is a customer of CP2, a regional fixed-line provider. Alice wants to call Bob. Both CPs have deployed PSTN2. Let's watch what happens during this call, step by step, in real-time.

Alice dials Bob's number on her mobile phone. Her device sends a SIP INVITE to CP1's network. CP1 receives the call request. Total elapsed time: 50 milliseconds. In the background, PSTN2 processes begin.

CP1 queries the PSTN2 directory: who hosts Bob's number? The directory, cached locally, responds instantly: CP2 hosts it. Here's CP2's IP address for direct routing. Elapsed time: 60 milliseconds. CP1 now knows where to send the call.

CP1 sends an authentication query to CP2: we have a call originating from Alice to Bob. Did CP1 originate this? CP1 responds: yes, authenticated. This proves the call is legitimate, not spoofed. Elapsed time: 150 milliseconds.

CP1 and CP2 negotiate encryption keys. They exchange certificates, generate ephemeral keys for this call only, and establish an SRTP encrypted media channel. All media will be end-to-end encrypted. Elapsed time: 250 milliseconds.

CP1 and CP2 establish a direct media connection, bypassing all transit providers. They negotiate codecs: Opus for high quality. They set up QoS parameters. The media path is ready. Elapsed time: 400 milliseconds. Now Bob's phone can ring.

CP1 sends call branding information to CP2: this call is from Alice, a verified customer. Here's her chosen display name and optional business logo. CP2 displays rich caller information on Bob's screen. Bob sees more than just a number.

Bob sees verified caller information and answers. The encrypted media path activates. Alice's voice travels directly from CP1 to CP2 with no intermediaries. The encryption ensures privacy. The direct path ensures quality. Elapsed time: 3.2 seconds from dial to conversation.

During the call, Alice and Bob enjoy HD audio quality. Opus codec provides natural-sounding voice. Direct routing means low latency, just 40 milliseconds. There are no dropped packets, no jitter. The conversation is crystal clear.

Now imagine Alice needs to call 999. CP1 recognizes the emergency number. CP1 queries Alice's device for real-time location: GPS coordinates, cell tower data, WiFi positioning. All of this goes to emergency services immediately. Not tomorrow's batch file, right now.

After Alice's call ends, CP1 updates its cache: Bob's number is at CP2, and the route works perfectly. Next time anyone from CP1 calls Bob, setup is even faster. The network learns and improves with each call.

Let's compare to traditional PSTN. Traditional: unknown caller ID authenticity, multiple transit hops, no encryption, basic voice quality, old emergency location data, 5 to 8 seconds setup time. PSTN2: verified caller, direct connection, end-to-end encrypted, HD quality, real-time emergency location, under 1 second setup.

Traditional call might cost 5 pence per minute due to transit fees. PSTN2 direct routing: less than 1 pence per minute. Over millions of calls, this saves millions of pounds. Savings can be passed to consumers or invested in better infrastructure.

To Alice and Bob, none of the technical complexity is visible. Alice dials, Bob answers, they talk. It just works, but better. Clearer audio, faster setup, more trust, better privacy. This is the promise of PSTN2: better technology, seamless experience.

This scenario demonstrates PSTN2's vision: advanced features working together seamlessly. Authentication, direct routing, encryption, branding, emergency location. Not as separate add-ons, but as integrated capabilities. This is the future of telecommunications, available today.