Sending billable event notifications (burl) to Index through server-side beaconing

You can use server-side A process where the header bidding takes place on an external server, as opposed to bidding from a browser. This is also called as server-to-server (S2S) header bidding. beaconing to send billing notifications (burl) to Index Exchange (Index). When you use server-side beconing, the burl is sent from your ad server A platform that manages, stores, and delivers advertisements to a publisher's site. or Server-Side Ad Insertion (SSAI Server-Side Ad Insertion (SSAI). The technology that combines ads into a video file on the server-side, then delivers video content with the ads embedded to the video player as one file. Also known as server-side ad stitching.) which is prompted by a billable event on the device or app. To use burl with Index, your SDK or server must support HTTP 302 redirects. To enable burl with Index, contact your Index Representative.

In the mobile app banner example below, the following steps describe how burl works in an OpenRTB An open industry standard for communication between buyers and sellers of online advertising in real-time bidding auctions. It's published by the IAB. interaction between a publisher The owner of a website or app where advertisements are served., Index, and a DSP Demand-Side Platform (DSP). A software platform that automates bidding decisions in real-time and efficiently connects buyers and audiences through an ad exchange or SSP. Also known as a buy-side platform..

Image showing steps described below

	The ad SDK generates an ad request and sends it to your ad server. The ad server then makes a bid request An OpenRTB request that is sent from a supply-side platform (SSP) or ad exchange to the DSP requesting a bid response for potential impressions. A bid request contains information about the impression that allows the DSP to decide whether to bid on the impression. to Index.
	Index sends a bid request to the DSP.
	The DSP sends a bid response An OpenRTB response that is sent by the DSP in response to the SSP's or ad exchange's bid request. It is an event directed back to the seller expressing a valuation for the request and conditions of sale. to Index that includes the following fields in the bid response object: `adm`: The creative A digital ad made available in various creative types, defined by their size in pixels such as 300x250px. markup to render on the user's device. `burl`: The DSP billing notice URL, to be sent when the impression becomes billable. Note: Index holds the auction data related to burls for three hours. This is referred to as the impression time to live (TTL). If Index receives the `burl` within the TTL, Index sends the DSP's `burl`, regardless of the DSP's expiry time. For more information about TTL, see How Index counts impressions.
	Index captures the DSP's `burl`.
	Index sends a bid response to your ad server that includes the following fields in the bid response object: `adm`: The creative markup (HTML or VAST Video ad-serving template (VAST). A communication standard between ad servers and video players in XML-format that describes the video player's expected behavior.), including the Index ad load notice. `burl`: The Index billing notice which is different from the DSP's billing notice burl (stored in step 4). This notifies Index that the publisher considers the impression billable.
	Your ad server conducts the final auction and if the bid wins the auction, the ad displays to the user.
	The ad is downloaded which causes the device to send the Index ad load notice, which was inserted in the ad markup (`adm`). This notifies Index that the ad has begun to render.
	The SDK reports an impression to your server when a billable event occurs on the client.
	Your server sends the Index `burl`. Note: You must include certain HTTP headers when firing the `burl` call to Index. For more information about HTTP headers, see List of HTTP headers to include in server-side beaconing (burl) calls sent to Index.
	Index retrieves the DSP `burl` (stored in step 4) and returns it to your server as an HTTP 302 redirect.
	Your server follows the HTTP 302 redirect to send the DSP `burl`.