# Configure the service general parameters

## Configure general parameters

1. When creating a new service, you can:

   - Specify its name and optionally the template that will be used to create this new service
   - Activate the hardware acceleration (Intel QSV)
   - Define the network interface used for ESAM out-of-band messages
   - Define the SCTE-104 network interface used for SCTE-104 out-of-band messages

> **Info:** See [General parameters](/beam/live-encoder/configure#configure-general-parameters) for more details.

2. You can activate automation mode and [configure the associated parameters](/beam/live-encoder/parameters/general) (see Technical Note _"Automation for scheduled blackout"_).

3. You can activate the synchronization between two services by ticking the corresponding checkbox (see [Synchronize two services](/beam/live-encoder/configure#synchronize-two-services) and [Split one OTT service on the same server](/beam/live-encoder/configure#split-one-ott-service-on-the-same-server). New parameters are displayed. Enter the appropriate value for each parameter.

4. You can activate the [dual output prevention](/beam/live-encoder/configure#configure-dual-output-prevention)

5. You can define variants: **Redundancy** for 1+1 redundancy (i.e. primary and secondary) and **Subsets**. These variants will be used in output streams to synchronize streams or to distribute the streams across multiple servers.

## Configure clock synchronization

By default, the Program Clock Reference (PCR) used in the encoder is locked to the input clock available in the source. As an alternative, Live Encoder can use the external NTP clock

> **Info:** **External SDI Genlock clock** is only visible if you set the [advanced parameter](/beam/live-encoder/configure/advanced-parameters) `enableExternalGenlockClock` to `true`.

> **Info:** When using the external NTP, it is not possible to enable the service synchronization feature (see [Synchronize two services](/beam/live-encoder/configure#synchronize-two-services)).

To synchronize the PCR to the external NTP clock, follow these steps:

1. From the **General** tab, go to the **Clock synchronization** section.

2. In the **Program Clock Reference (PCR)**, select either **External NTP clock** or **External SDI Genlock clock** from the drop-down menu.

3. Select a **Save** option to save changes.

## Synchronize two services

Before you start, ensure the two services are identical, same address and same port.

To synchronize two services and achieve the 1+1 redundancy, follow these steps:

1. From the **General** tab, go to the **Services synchronization** section then tick the **Activate** checkbox. Parameters related to the synchronization are displayed.

2. You can edit the [synchronization parameters](/beam/live-encoder/parameters/general#synchronization-of-services).

3. From the **Output** tab, click `Edit` to edit the output parameters.

4. In the **General parameters** section, tick the **Synchronize** checkbox. The synchronization is automatically activated in the output, but you can deactivate it (see [Output parameters](/beam/live-encoder/parameters/output#general-mpeg-2-ts-parameters)).

5. Select a **Save** option to save changes.

## Split one OTT service on the same server

Before you start: ensure the two services are identical, same address and same port.

On SG1-based systems, there are multiple GPUs. In some instances, it can be necessary to create a large ABR ladder that cannot fit on a single GPU.

To split an OTT service on the same server, follow these steps:

1. From the **General** tab, define two (or more) QSV services and assign each to a different **QSV Device**.

2. For both services, go to the **Service synchronization** section then tick the **Activate** checkbox. Parameters related to the synchronization are displayed.

3. Edit an identical configuration for both services (see [Synchronize two services](/beam/live-encoder/configure#synchronize-two-services)).

   1. Enter a memorable identifier for the **Pool name** (in our example, **SG1**).

   2. Select a **Network interface** that can be used for the communication multicast then enter a multicast address and port.

      ![](/_machine-assets/bb29eef7fca515116bb6ebe1e4fc4a18707a4fc680a35000078bceed477a4e10.png "Example of configuration for a pair of synchronized
      services")

4. In the **Input** tab, configure both services to ingest the same source.

5. In the **Encoding** tab, ensure that all encoders have matching **GOP settings**.

6. Ensure that all the output multicasts are on different address/port combinations.

7. In the **Output** tab, click `Edit` to edit the output parameters then from the

8. In the **General parameters** section, tick the **Synchronize** checkbox. The synchronization is automatically activated in the output, but you can deactivate it (see [Output parameters](/beam/live-encoder/parameters/output#general-mpeg-2-ts-parameters)).

9. Select a **Save** option to save changes.

## Configure dual-output prevention

The dual output prevention feature allows the operator to prevent from duplicate media multicast on the same network, especially in the case of active/active encoders.

This feature is based on the Multicast Guard Protocol (MGP) according to the following principles:

- Point-to-point communication between both encoders using multicast messages on a dedicated port.
- Both encoders constantly check that one and ONLY one encoder has its output enabled.

![EL dual output prevention diagram](/_machine-assets/b02802fa09365e5cc0f76af256632b82d251b4a62b98caa4a879556bb2cc09fc.png)

> **Info:** By default, the first encoder that starts has its output enabled, but you can force the output status via the API.

Benefits for the operator are:

- Remove network multicast conflicts
- Protect against management communication loss
- Near-seamless switching during manual failover

To configure dual-output prevention, follow these steps:

1. On the first encoder, click the **General** tab then go to the **Dual output prevention** section and tick the **Activate** checkbox. Parameters related to the dual output prevention are displayed.

2. You can edit the dual output prevention parameters:

   | Parameter         | Description                                                                                  |
   | :---------------- | :------------------------------------------------------------------------------------------- |
   | Network interface | Name of the network interface used to communicate between the two encoders.                  |
   | Address           | Multicast address used to communicate between the two encoders.                              |
   | Port              | Port used to communicate between the two encoders.                                           |
   | Group name        | Group name that identifies the pair of encoders for which dual output prevention is managed. |

> **Info:** These parameters must be the same for both encoders.

3. Repeat steps #1 to #3 on the second encoder.

4. Select a **Save** option to save changes.

5. You can go to the **Statistics** > **Outputs** to view the encoder status (enabled/disabled).

![EL dual output prevention stats](/_machine-assets/922f4b8ec5b23e5dbeb2abc681c3c92ee68e6e63cc24f7f8695231fc18f7e4ac.png)

**See also**\

[Dual-output prevention parameters](/beam/live-encoder/parameters/general#dual-output-prevention)

## Create server variants

There are two types of server variants:

- variants based on redundancy: primary and secondary
- variants based on a defined subset

Once created, these variants can be used to synchronize streams or to distribute the streams across multiple servers.

### Create redundancy variants

To create redundancy variants, follow these steps:

1. From the **General** tab, go to the **Server variant configuration** section.

2. Tick the **Activate** checkbox. Primary and secondary variants are automatically created.

3. Click `Edit` to edit the [**Server tags**](/beam/live-encoder/parameters/general#redundancy).

### Create subset variants

To create subset variants, follow these steps:

1. From the **General** tab, go to the **Variants** section.

2. In the **Subset** subsection, click **Add**. A new window is displayed.

3. Enter a subset **Name**, for example **SD** or **HD** and **Server tags** (see [Server variant parameters](/beam/live-encoder/parameters/general#subset)).

4. Click **Ok** to save.

5. You can use these subsets to synchronize streams or to distribute the streams across multiple servers (see [Link an output stream to a predefined subset](/beam/live-encoder/configure/output/configure-output#link-an-output-stream-to-a-predefined-subset).