# Audio over IP - Senders

## Senders

The **Senders (TX)** section under **AoIP** contains the transmit streams configured on the flexAI system.

Use **ADD** to create a new sender. Existing senders are listed below **Senders (TX)** and can be selected individually for configuration. Use **DEL** to remove selected senders.

Some sender parameters are only visible when **Show Expert Settings** is enabled.

[![AoIP Sender 1](https://docs.junger.audio/uploads/images/gallery/2026-09/scaled-1680-/wKhmaKtULlC6TgY0-aoip-sender-1.png)](https://docs.junger.audio/uploads/images/gallery/2026-09/scaled-1680-/wKhmaKtULlC6TgY0-aoip-sender-1.png)

### Protocol

<table id="bkmrk-parameter-values-def"><thead><tr><th>Parameter</th><th>Values</th><th>Default</th><th>Description</th></tr></thead><tbody><tr><td>Protocol Selection</td><td>Available AoIP protocols</td><td>-</td><td>Selects the protocol used by the sender. The available settings may change depending on the selected protocol.</td></tr></tbody></table>

### Status

The **Status** section shows the current operating state of the sender and provides the SDP describing the transmitted stream.

<table id="bkmrk-parameter-values-def-1"><thead><tr><th>Parameter</th><th>Values</th><th>Default</th><th>Description</th></tr></thead><tbody><tr><td>Session Status</td><td>Status</td><td>-</td><td>Shows the overall status of the transmit session.</td></tr><tr><td>RTP Status</td><td>Status</td><td>-</td><td>Shows whether RTP packets are currently being transmitted.</td></tr><tr><td>SDP</td><td>Status / SDP data</td><td>-</td><td>Shows the Session Description Protocol data generated for the transmitted stream. This information can be used to configure compatible receivers.</td></tr><tr><td>Provisional Stream Status</td><td>Diagnostic information</td><td>-</td><td>Provides detailed sender statistics and diagnostic information about the outgoing RTP stream.</td></tr><tr><td>Reset Sender Status</td><td>Button</td><td>-</td><td>Resets the displayed sender status and diagnostic counters.</td></tr><tr><td>RTP Status – Leg 1</td><td>Status</td><td>-</td><td>Shows the transmit status of the first stream leg.</td></tr><tr><td>RTP Status – Leg 2</td><td>Status</td><td>-</td><td>Shows the transmit status of the redundant second stream leg when ST 2022-7 is used.</td></tr></tbody></table>

To copy the complete SDP, move the pointer over the displayed **SDP**. A copy control appears; click it to copy the SDP to the clipboard. The copied SDP can then be pasted directly into a compatible receiver or another application.

The **Provisional Stream Status** is primarily intended for diagnostics and troubleshooting. For normal operation, the Session and RTP status indicators provide the most relevant overview.

### Settings

The **Settings** section defines the format and network properties of the transmitted stream.

<table id="bkmrk-parameter-values-def-2"><thead><tr><th>Parameter</th><th>Values</th><th>Default</th><th>Description</th></tr></thead><tbody><tr><td>Enable</td><td>On / Off</td><td>-</td><td>Enables or disables the sender.</td></tr><tr><td>Stream Name</td><td>Text</td><td>-</td><td>Defines the name used to identify and advertise the transmitted stream.</td></tr><tr><td>Channel Count</td><td>Supported channel counts</td><td>-</td><td>Defines the number of audio channels carried by the stream.</td></tr><tr><td>Packet Time</td><td>Supported packet times</td><td>-</td><td>Defines the duration of audio carried by each RTP packet. Shorter packet times reduce transport latency but increase the packet rate and processing load.</td></tr><tr><td>Seamless Protection Switching (ST 2022-7)</td><td>On / Off</td><td>-</td><td>Enables SMPTE ST 2022-7 seamless protection switching. When enabled, two equivalent stream legs are transmitted over separate network paths.</td></tr><tr><td>Codec</td><td>Available codecs</td><td>-</td><td>Defines the audio codec or sample format used for the transmitted stream.</td></tr><tr><td>DSCP</td><td>Auto / Available DSCP values</td><td>-</td><td>Defines the Differentiated Services Code Point used to classify the outgoing RTP traffic for Quality of Service (QoS). **Auto** applies the DSCP value configured for the corresponding stream type and packet time on the AoIP Setup page.</td></tr><tr><td>Auto RTP Payload Type</td><td>On / Off</td><td>-</td><td>Automatically assigns the RTP payload type. Disable this option to specify the payload type manually.</td></tr><tr><td>RTP Payload Type</td><td>RTP payload type</td><td>-</td><td>Defines the RTP payload type when automatic assignment is disabled.</td></tr><tr><td>RTP Port</td><td>Port number</td><td>-</td><td>Defines the UDP destination port used for the RTP stream.</td></tr><tr><td>TTL</td><td>Number of network hops</td><td>-</td><td>Defines the IP multicast Time To Live (TTL), limiting how many routed network hops the multicast stream can traverse.</td></tr></tbody></table>

**DSCP (Differentiated Services Code Point)** allows network infrastructure to classify AoIP traffic for Quality of Service. Switches and routers can use this marking to give time-critical audio traffic the required priority over less critical network traffic.

[![AoIP Sender 2](https://docs.junger.audio/uploads/images/gallery/2026-09/scaled-1680-/CoL5jHZgPSeWm6wO-aoip-sender-2.png)](https://docs.junger.audio/uploads/images/gallery/2026-09/scaled-1680-/CoL5jHZgPSeWm6wO-aoip-sender-2.png)

### Stream Legs

Each sender can use up to two stream legs. **Leg 1** carries the primary stream. **Leg 2** carries an equivalent redundant stream when **ST 2022-7** is enabled.

<table id="bkmrk-parameter-values-def-3"><thead><tr><th>Parameter</th><th>Values</th><th>Default</th><th>Description</th></tr></thead><tbody><tr><td>Destination IP Address – Leg 1</td><td>Multicast IP address</td><td>-</td><td>Defines the multicast destination address used to transmit the first stream leg.</td></tr><tr><td>Media Interface – Leg 1</td><td>Available Media Interfaces</td><td>-</td><td>Selects the Media Interface used to transmit the first stream leg.</td></tr><tr><td>Destination IP Address – Leg 2</td><td>Multicast IP address</td><td>-</td><td>Defines the multicast destination address used to transmit the redundant second stream leg.</td></tr><tr><td>Media Interface – Leg 2</td><td>Available Media Interfaces</td><td>-</td><td>Selects the Media Interface used to transmit the redundant second stream leg when ST 2022-7 is enabled.</td></tr></tbody></table>

<p class="callout info">Each sender can be assigned individually to one of the available **Media Interfaces**. This allows different senders, and, with ST 2022-7, individual stream legs, to use separate physical AoIP networks.</p>

<p class="callout success">In combination with the internal audio routing, flexAI can also transfer audio between otherwise independent AoIP networks: audio received through one Media Interface can be routed internally and transmitted again through a sender assigned to another Media Interface. This operates at the audio level rather than as a network bridge.</p>

With **ST 2022-7** enabled, both legs carry equivalent audio data over independent network paths. A compatible receiver can use both legs for seamless protection against packet loss or a failure of one network path.

### Livewire Sender Settings

When **Livewire** is selected under **Protocol Selection**, some sender parameters differ from those used for ST 2110.

[![AoIP Sender 3 Livewire](https://docs.junger.audio/uploads/images/gallery/2026-09/scaled-1680-/2sn9HkyMv2TUEPMt-aoip-sender-3-livewire.png)](https://docs.junger.audio/uploads/images/gallery/2026-09/scaled-1680-/2sn9HkyMv2TUEPMt-aoip-sender-3-livewire.png)

The general sender controls, status information, packet time, DSCP, and redundancy settings operate in the same way as described above. Livewire additionally uses a **Livewire Channel** to identify the transmitted stream.

<table id="bkmrk-parameter-values-def-4"><thead><tr><th>Parameter</th><th>Values</th><th>Default</th><th>Description</th></tr></thead><tbody><tr><td>Destination IP Address – Leg 1</td><td>Multicast IP address</td><td>-</td><td>Shows or defines the multicast destination address used for the first Livewire stream leg.</td></tr><tr><td>Livewire Channel – Leg 1</td><td>Livewire channel number</td><td>-</td><td>Defines the Livewire Channel used for the first stream leg. The channel number identifies the stream within the Livewire network and corresponds to its multicast destination.</td></tr><tr><td>Media Interface – Leg 1</td><td>Available Media Interfaces</td><td>-</td><td>Selects the Media Interface used to transmit the first Livewire stream leg.</td></tr><tr><td>Destination IP Address – Leg 2</td><td>Multicast IP address</td><td>-</td><td>Shows or defines the multicast destination address used for the redundant second Livewire stream leg.</td></tr><tr><td>Livewire Channel – Leg 2</td><td>Livewire channel number</td><td>-</td><td>Defines the Livewire Channel used for the redundant second stream leg.</td></tr><tr><td>Media Interface – Leg 2</td><td>Available Media Interfaces</td><td>-</td><td>Selects the Media Interface used to transmit the redundant second stream leg when ST 2022-7 is enabled.</td></tr></tbody></table>

As with other sender types, **Leg 2** is used when **Seamless Protection Switching (ST 2022-7)** is enabled.