Introducing Open Voice Shield

Voice fraud does not announce itself in signalling. A scam call connects like any other call: the INVITE is well-formed, the media flows, the CDR looks ordinary. The fraud is in what was said: an impersonated bank, a pressured victim, a callee leg that quietly turned into a recording. Meanwhile the evidence an operator would need is scattered: the audio is on one system or nowhere, the packet trace on another, the CDR on a third. So blocking decisions get made on complaints and gut feel, without proof, which means they get made late, or wrongly, or not at all.

You whitelist your SIP server's IP, point a trunk at the ingress, and route calls, all of them or a sample, through Open Voice Shield on the way to the destination you configure. The hop authorizes each call by source IP, relays the signalling and media untouched, and records caller and callee on separate channels as the call passes. After hangup, each channel is transcribed and the conversation is analyzed by a language model. The verdict is attached to the call record minutes later, with the recording, transcript, packet capture and SIP ladder alongside it. The live call is not interrupted. Enforcement happens on the next call, which an automation rule can block or divert at authorization. The full path, with the diagram, is on how it works.

• A fraud probability: how likely the call is fraudulent, as a number you can threshold.
• A category and an impersonated entity: what kind of scam, and who the caller claimed to be.
• Red flags and a summary: the specific moments in the transcript that drove the score.
• A TCPA risk comment: consent and robocall-exposure observations on the call.
• A recommendation: block, review or allow, ready to feed an automation rule.
• The evidence pack: recording, per-channel transcript, pcap and SIP ladder, exportable as an offline bundle for a dispute or a case file.

Field-by-field detail lives in the concepts guide. The full feature list is on features.

Fraud runs in both directions. The verdict scores the caller. Independently, the analysis reads the callee channel of every call for false answer supervision, a route whose vendor silently switches the audio to recorded playback mid-call to pad the billed minutes. That check raises a route alert, distinct from the caller verdict, naming the route whose vendor should come out of rotation. How that works, and why dial-test campaigns structurally miss it, is on FAS detection.

You do not have to migrate your traffic to try this. Because Open Voice Shield is an ordinary SIP hop, your dial plan can route a random share of live calls through it (one in ten, one in twenty) and send the rest directly. Every sampled call is fully analyzed and fully evidenced, and patterns show up in samples: a scam campaign and a playback- swapped route are both behaviours across calls, not single events. Sampling trades coverage for cost: it catches patterns, not every individual call.

Open Voice Shield is built for people who already run SIP trunks and think in packets and rates: NOC engineers and carrier or wholesale operations teams watching route quality, CCaaS, UCaaS and CPaaS platforms whose customers' calls ride on bought termination, call-centre operations managers fielding the complaints, and telecom security teams who need a defensible record behind every block. If your switch can add one hop to a dial plan, you can use it.

Billing is prepaid: pay-as-you-go has no monthly fee and charges each call for its minutes plus one flat analysis fee, with plan bundles for steady volume. The current rates are on pricing.

Signup is self-serve and needs no card: create an account, whitelist the IP your switch sends from, point a trunk at the ingress address on your Network page, and place a test call. The getting-started guide walks through each step. Open Voice Shield is built and operated by TelecomsXChange. Questions that the site does not answer go to the team.

There is nothing to install or host. Your switch keeps its routing, and one dial-plan entry decides how much traffic the hop sees.