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T10 · T10-R01

Phone fork and network fork

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Learn it in 5 minutes

  • The CUCM 15 feature guide says phone-based recording takes media from the phone. The phone forks two streams to the recording server.
  • The same guide says network-based recording can take media from the phone or the gateway, and the gateway connects to Unified CM over a SIP trunk.
  • Using the phone as the source requires the built-in bridge. The phone's setting overrides the cluster-wide default when it is not left at default.
  • The guide says recording can fail if the built-in bridge is on and Media Termination Point Required is checked.
  • Cisco's basic recording note says a phone outside the managed network cannot use this fork unless it can send RTP to the recorder.
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Visual

Phone fork and network fork diagram
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What is going on

A recording is a copy of the media, sent somewhere on purpose. It is not a second conversation and it is not proof the agent heard the caller. CUCM decides the source. The feature guide tells you to prefer the phone or the gateway on the line, then shows a table for when that preference is not what CUCM selects. Multi-fork, in that guide, sends the stream to a CUBE media proxy that can relay it to up to five recording servers. Automatic and selective recording are both named. Read the call flow for the release you run before you change a line.

Confirm before relying. Confirm codec support and secure-recording settings in the feature guide for your CUCM version.

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Worked example

An agent phone has the built-in bridge off. The line is set to record from the phone. The call completes and the recorder is empty. The signaling ladder can still show a normal 200. The missing object is the fork, not the dial plan.

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Quiz

1. A 200 OK proves the recorder received both audio directions.

2. The built-in bridge on one phone always follows the cluster-wide parameter.

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Ecosystem

Sister pieces sit on the ecosystem page: the glossary, the mind map, the integration map, and the sibling labs.

  • Built-in bridge — The phone feature CUCM uses when the phone itself forks recording media.
  • Fork — A copy of the media stream sent to a recorder.

Config. Write phone or gateway as the intended source, and whether the built-in bridge is on.

Troubleshooting. If the call is fine and the file is silent, compare the recorder address with the SDP of the fork.

Bridge. A contact-center agent is still a CUCM line for this feature. The quality score lives in another product.

Mind map, sister technologies, and future hooks live on the ecosystem page.

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Sources

Product screens move. Confirm the guide for your release before you change a live system.

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Sources and go deeper

Opened 2026-10. A row marked confirm has no link, because that page was not verified.

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