# MediaTailor protocol-specific parameter behavior
MediaTailor protocol-specific behavior

AWS Elemental MediaTailor handles manifest query parameters differently for HLS and DASH protocols. Each protocol type has specific application locations and processing methods.

**HLS vs DASH parameter handling comparison**  
The following table compares how MediaTailor handles manifest query parameters across HLS and DASH protocols:


| Aspect | HLS Behavior | DASH Behavior | 
| --- | --- | --- | 
| Parameter application | Applied directly to manifest URLs and segment URLs | Applied to Location elements, SegmentTemplate attributes, and segment URLs | 
| Manifest hierarchy | Multivariant playlist → Media playlists→ Segments | MPD → Periods → AdaptationSets → Representations | 
| Initialization URLs | Applied to HLS init URLs when present | Applied to SegmentTemplate initialization attributes | 
| Session handling | Parameters preserved across playlist updates | Parameters included in MPD Location element for session continuity | 
| Ad segment handling | Applied to ad segment URLs in media playlists | Applied to ad period SegmentTemplate media attributes | 

**Parameter application locations**  
MediaTailor applies manifest query parameters to the following locations:

## HLS parameter application


For HLS streams, MediaTailor applies manifest query parameters to:
+ **Multivariant playlist URLs:** Parameters are appended to media playlist references
+ **Media playlist URLs:** Parameters are included in segment URLs within media playlists
+ **Content segment URLs:** All content segments include the manifest query parameters
+ **Ad segment URLs:** Ad segments receive parameters for CDN routing and authorization
+ **HLS initialization URLs:** Init segments include parameters when present in the stream
+ **Slate segment URLs:** Slate content includes parameters for consistent CDN behavior

**Example HLS parameter application example**  
Given the session initialization:  

```
GET /v1/master/123456789/originId/index.m3u8?manifest.auth_token=abc123&manifest.region=us-west
```
The multivariant playlist includes parameters in media playlist references:  

```
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:BANDWIDTH=2665212,RESOLUTION=960x540
../../../manifest/123456789/originId/session/0.m3u8?auth_token=abc123&region=us-west
```
The media playlist includes parameters in segment URLs:  

```
#EXTM3U
#EXT-X-VERSION:6
#EXT-X-TARGETDURATION:7
#EXTINF:6.006,
https://origin.com/segment1.ts?auth_token=abc123&region=us-west
#EXTINF:6.006,
../../../../segment/123456789/originId/session/0/2?auth_token=abc123&region=us-west
```

## DASH parameter application


For DASH streams, MediaTailor applies manifest query parameters to:
+ **MPD Location elements:** The Location element includes parameters for manifest refresh requests
+ **SegmentTemplate initialization attributes:** Init segment URLs include parameters
+ **SegmentTemplate media attributes:** Media segment URL templates include parameters
+ **Content segment URLs:** All content segments generated from templates include parameters
+ **Ad segment URLs:** Ad period segments include parameters for CDN integration
+ **Server-side reporting redirects:** 302 redirects to ad segments preserve parameters

**Example DASH parameter application example**  
Given the session initialization:  

```
GET /v1/dash/123456789/originId/index.mpd?manifest.auth_token=abc123&manifest.region=us-west
```
The DASH manifest includes parameters in multiple locations:  

```
<MPD>
    <Location>https://mediatailor.com/v1/dash/123456789/originId/index.mpd?auth_token=abc123&region=us-west&aws.sessionId=session</Location>
    <Period>
        <AdaptationSet>
            <Representation>
                <SegmentTemplate 
                    initialization="init.mp4?auth_token=abc123&region=us-west" 
                    media="segment_$Number$.mp4?auth_token=abc123&region=us-west"/>
            </Representation>
        </AdaptationSet>
    </Period>
</MPD>
```