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The toll-fraud class, stated defensively

Four exposure classes, source restrictions, and caller-identity as a separate control.

Learn in 5 minutes

  1. Name the four exposure classes
  2. Point prevention at source restrictions and the numbering plan
  3. Keep STIR identity separate from the trusted list

Visual

An intended path among lab addresses · study drawing · cyphermonkeylabs.com CUCMCUBECarrier INVITE 100 INVITE 200

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Recognition and prevention. This lesson does not build the sessions it warns about.

Worked example

Name the listed source Which source address on the first hop is the listed call agent?

  1. Press Play.
  2. Step until the hop named in the question.
  3. Inspect that message and answer the check.

Vendor menus, ports, and license names change. Confirm before relying on a sentence that is not an RFC.

Fault

A trunk shows a signed calling identity and the operator removes the trusted list because the identity passed.

RFC 8224 and the FCC page cover caller identity. CME and SRST cover who may send signaling.

Quiz

Unauthenticated INVITEs from the internet are closed by


A weak digest password in this lesson means


A dial-peer that matches too widely is fixed by


FCC call authentication is cited here for


RFC 8224 in this lesson is


The ladder in this lesson shows


Ecosystem

Glossary, sister systems, and the integration seam for this room.

Workforce management WFM forecasts volume and builds schedules. It consumes contact-center events. It does not parse Via headers. When a forecast is wrong, the SIP symptom is usually queue delay and 480 or carrier congestion, not a broken dialog ID.

Glossary · Ecosystem map · Ports · Troubleshooting

Sources and go deeper