# Setting up for virtual input switching


With virtual input switching, the Elemental Live event and the POIS must be set up with identical information. 

The setup steps are the same for asynchronous input switching and SCTE-35-triggered input switching.

**Topics**
+ [

# Overview
](vips-setup-overview.md)
+ [

# Step 1: Coordinate with the POIS operator
](vips-setup-step-coordinate.md)
+ [

# Step 2: Set up the event
](vips-setup-step-event.md)
+ [

# Step 3: Set up the inputs in the event
](vips-setup-step-inputs.md)
+ [

# Step 4: Start the event
](vips-setup-step-start.md)

# Overview


The POIS must be set up with the following information:
+ A tag for the Elemental Live input. Each input must be unique in the Elemental Live event.
+ The acquisition point ID and zone for the Elemental Live event.

 In Elemental Live, you set up the event with the following information:
+ Acquisition point ID. This ID is how the POIS identifies the Elemental Live node. The POIS provides you with this ID.
+ Zone. This ID is how the POIS identifies the specific event. The POIS provides you with this ID.
+ These two fields set up Elemental Live and the POIS to have a common identifier for the event.

In the event, you set up the inputs with the following information:
+ Input ID. This is the standard ID that Elemental Live generates and assigns when you save an event.
+ The URL for the input.
+ Label. This tag has the same value as the label (in Elemental Live). In this way, both Elemental Live and the POIS have a common identifier for each input.
+ A virtual tag. This identifies the input as one that the POIS knows about. Typically, you set up all the inputs in an event as virtual. 

## Number of nodes and number of POIS

+ Each Elemental Live node can communicate with only one POIS. All the events on the Elemental Live node must be configured for the same POIS.
+ One POIS can communicate with several Elemental Live nodes. The POIS uses the POIS AcquisitionPointID and ZoneID parameter to uniquely identify each Elemental Live node.

## Number and type of inputs


With asynchronous input switching, the inputs can be any of the following:
+ Programs in one MPTS. You can set up a maximum of 11 programs.
+ Any type of input that Elemental Live considers to be a file input. See [Supported upstream systems for file inputs](supported-inputs-file-types.md). 

  There is no limit to the number of inputs of this type.

With SCTE-35-triggered input switching, the inputs can be any of the following:
+ Programs in one MPTS. You can set up a maximum of 11 programs.

# Step 1: Coordinate with the POIS operator


Talk to the POIS operator, and agree on the values for this data:
+ The label for each input. This value must be identical, and it is case sensitive.
+ The acquisition ID for the Elemental Live node. The POIS must have a different acquisition ID for each Elemental Live node that it works with.
+ The zone ID for the specific event. 

  The combination of acquisition ID and zone ID must be unique in the Elemental Live event.
+ The URL for the signal conditioner endpoint on the POIS. This endpoint handles the input switching communications with Elemental Live.
+ The URL for the alternate signal conditioner endpoint on the POIS, if this exists.
+ The preroll that is the number of seconds between when Elemental Live receives the request from the POIS and when Elemental Live inserts any SCTE-35 messages in the content. This preroll isn't required if the messages that the POIS sends include a start time for the input switch,

Make a note of all of this data. You will need it to set up on Elemental Live. 

# Step 2: Set up the event


These steps show you how to configure the event with information about the POIS server.

The information in this section assumes that you are familiar with the general steps for creating an event. 

**Note**  
The information in this section assumes that you are familiar with the general steps for creating an event. 

1. On the web interface, open the **Ad Avail Controls** section of the event.

1. Complete the fields as follows:
   + **Ad Avail Trigger**: ESAM.
   + **Acquisition Point Identifier**: The value that you [obtained from the POIS operator](vips-setup-step-coordinate.md).
   + **Zone Identity**: The value that you obtained from the POIS operator.
   + **Signal Conditioner Endpoint**: The URL that you obtained from the POIS operator.
   + **Alternate Signal Conditioner Endpoint**: The URL that you obtained from the POIS operator, if any.
   + **Response Signal Preroll**: The value you obtained from the POIS operator, if any. 
   + Other fields: The other fields in this section aren't used for virtual input switching.

1. Complete this field only if you want to enable asynchronous input switching:
   + **Unsolicited ESAM Server**. 

# Step 3: Set up the inputs in the event


**To set up an MPTS program**

You must set up each program in the MPTS as an individual input. 

You can use inputs from an MPTS with both asynchronous input switching and SCTE-35-triggered input switching.
**Note**  
The information in this section assumes that you are familiar with the general steps for creating an event. 

1. On the web interface, got to the **Inputs** section of the event.

1. Complete the **Input** section as follows:
   + **Input Type**: Choose Network Input.
   + **Input Name**: Enter the label for the input, obtained from the POIS operator.
   + **Network Location**: The URL of the MPTS. For example, udp://192.20.08.18:5001

1. Open the **Advanced** section of this input and complete the following fields (on the first line of fields)
   + **Virtual Input**: Choose this field to set up the input as a virtual input. Elemental Live notifies the POIS only about inputs that are configured as virtual inputs.
   + **Virtual Input SCTE 35 PID**: Enter the PID in the MPTS that holds the SCTE-35 data stream. You complete this field only if you are using this program with SCTE-35-triggered input switching. This is the PID that Elemental Live probes for SCTE-35 messages to send to the POIS.

1. Go to the **Video Selector** section of this input and complete the following fields:
   + **Program**, in **Video Selector**: Enter the program number of the individual program in the mpts.

1. Set up the audio and captions for this MPTS in the usual way.

1. Set up more inputs, for other programs in the MPTS. For all the inputs, these rules apply:
   + The URLs must be identical, because the programs must all be in the same MPTS.
   + The Input names must each be different.
   + The Program (in the Video Selector) must each be different.

**To set up a file input**

You can use file inputs with asynchronous input switching. You can't use them with SCTE-35-triggered input switching.
**Note**  
The information in this section assumes that you are familiar with the general steps for creating an event. 

1. On the web interface, got to the **Inputs** section of the event.

1. Complete the **Input** section as follows:
   + **Input Type**: Choose File Input or HLS File Input.
   + **Input Name**: Enter the label for the input, obtained from the POIS operator.
   + **File Location**: The path and file name for the source. For example, ftp://vod\$1files/mlaw.wav

1. Open the **Advanced** section of this input and complete the fields as follows:
   + **Virtual Input**: Choose this field to set up the input as a virtual input. Elemental Live notifies the POIS only about inputs that are configured as virtual inputs.
   + **Virtual Input SCTE 35 PID**: Ignore this field. It is used only with SCTE-35-triggered input switching. 

# Step 4: Start the event


When you start the event, Elemental Live ingests inputs, starting with the first input listed in the event. While the event is running, Elemental Live responds to POIS requests to switch to a different input. The role of Elemental Live is reactive. The POIS controls input switching.