# Set up third-party CDNs for MediaTailor ad delivery
Third-party CDNs like Akamai and Fastly can significantly improve the performance and scalability of your AWS Elemental MediaTailor ad delivery while reducing bandwidth costs. However, CDN configuration for personalized advertising requires specific settings that differ from standard video delivery.
For information about passing query parameters through third-party CDNs, see [MediaTailor manifest query parameters](manifest-query-parameters.md). For advanced routing configurations using dynamic variables, see [MediaTailor dynamic ad variables for ADS requests](variables.md).
This guide walks you through the complete process of setting up your third-party CDN to work optimally with MediaTailor. You'll learn how to configure two essential behaviors:
+ **Manifest bypass:** Ensures each viewer receives personalized ad insertions by preventing manifest caching
+ **Segment caching:** Maximizes performance and reduces costs by efficiently caching video content
The configuration process typically takes 30-60 minutes and includes provider selection, setup, verification, and optimization. Once complete, you'll have a CDN configuration that delivers personalized ads efficiently while maintaining optimal viewer experience.
**Note**
This guide focuses on Akamai and Fastly configurations. For CloudFront setup instructions, see [CloudFront integration](cloudfront-specific-recommendations.md).
## Prerequisites
Before setting up your third-party CDN with MediaTailor, make sure you have:
+ An active MediaTailor configuration that includes your content origin and ad decision server
+ Access to your CDN's configuration interface
+ A list of file extensions used in your content (.m3u8, .mpd, .ts, and so on)
+ Your CDN provider's documentation for reference
For CloudFront setup instructions instead of third-party CDNs, see [CloudFront integration](cloudfront-specific-recommendations.md).
**Terminology**
To understand CDN configuration requirements, you need to know these manifest types:
+ **HLS manifests**:
+ *Multivariant playlist*: The top-level manifest that contains links to media playlists
+ *Media playlist*: The second-level manifest with links to content segments
+ **DASH manifests**:
+ *MPD (Media Presentation Description)*: The standard term for DASH manifests
This guide refers to all manifest files (multivariant playlists, media playlists, and MPDs) collectively as *manifests* when discussing common configuration requirements.
For general CDN configuration principles that apply to all providers, see [Set up CDN integration with MediaTailor](cdn-configuration.md).
For CDN optimization guidance, see [Performance optimization guide for CDN and MediaTailor integrations](cdn-optimization.md).
## Configure CDN caching rules
CDN caching configuration is critical for MediaTailor ad delivery because it determines how your content reaches viewers. Proper configuration ensures that manifests remain personalized for each viewer while segments are efficiently cached to reduce origin load and improve performance.
This configuration typically takes 15-30 minutes per CDN provider and requires two distinct behaviors:
+ **Manifest handling:** Prevents caching to ensure each viewer receives personalized ad insertions
+ **Segment caching:** Maximizes cache efficiency for video content to improve delivery performance
Follow these steps to configure your CDN's caching rules for optimal ad delivery.
Choose your CDN provider from the following tabs for specific instructions:
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#### [ Akamai ]
Configure these two behaviors in your Akamai property:
+ Manifest handling to prevent caching
+ Segment caching for optimal performance
**Configure manifest delivery**
Configure your Akamai CDN to avoid caching manifests so that each viewer receives personalized ads.
Manifest files contain the personalized ad insertion points that MediaTailor generates for each viewer. Caching these files would result in all viewers seeing identical ads, defeating the purpose of personalized advertising.
Follow these steps for manifest requests (files ending in .m3u8, .mpd, or .smil):
1. Create a behavior to match manifest file extensions (.m3u8, .mpd, .smil)
1. Set **Caching Option** to **No Store**
1. Configure cache keys to include all query parameters
1. Enable **Forward Host Header** for proper origin routing
1. Configure header forwarding for all headers. For minimum requirements, see [Required headers for MediaTailor CDN integration](cdn-configuration.md#cdn-required-headers).
**Configure segment delivery**
Configure your Akamai CDN to cache video segments to maximize CDN efficiency and reduce origin load.
Video segments are the actual content files that can be safely cached because they don't contain personalized information. Proper segment caching reduces bandwidth costs and improves playback performance for viewers.
Follow these steps for segment requests (files ending in .ts, .mp4, .m4s, and so on):
1. Create a behavior to match segment file extensions (.ts, .mp4, .m4s)
1. Set **Honor Origin Cache Control** to **Yes**
1. Configure default time-to-live (TTL) settings for when origin headers are missing:
+ Default TTL: 86400 seconds (24 hours)
+ Maximum TTL: 604800 seconds (7 days)
**Note**
After configuring these behaviors, activate your property changes in Akamai Control Center.
The changes take effect after activation.
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#### [ Fastly ]
Create these two configurations in your Fastly service:
+ Manifest handling to prevent caching
+ Segment caching for optimal performance
**Configure manifest delivery**
Configure your Fastly CDN to bypass caching for manifest files so that each viewer receives personalized ad content.
Manifest files must reach MediaTailor for each request to ensure proper ad personalization. Bypassing the cache for these files ensures that each viewer's unique targeting parameters are processed correctly.
Follow these steps for manifest requests:
1. Create a request condition to identify manifest paths
1. Set cache condition to **Do not cache** for these requests
1. Configure **Forward** settings to include all query parameters
1. Add `User-Agent` to your header forwarding configuration
**Configure segment delivery**
Configure your Fastly CDN to cache video segments to improve delivery performance and reduce origin traffic.
Segment caching is essential for cost-effective delivery and optimal viewer experience. These files are identical for all viewers and benefit significantly from CDN caching.
Follow these steps for segment requests:
1. Create a request condition to identify segment paths
1. Set **Cache Settings** to **Honor origin cache headers**
1. Configure default time-to-live (TTL) to 86400 seconds (24 hours) for when origin headers are missing
**Note**
After making these changes, activate a new version of your Fastly service.
The configuration takes effect after activation.
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## Verify your CDN configuration
Verification ensures that your CDN configuration works correctly before you direct production traffic through it. These tests confirm that ad personalization functions properly and that caching provides the expected performance benefits.
Complete verification typically takes 10-15 minutes and should be performed from multiple geographic locations if possible.
After setting up your CDN, perform these checks to verify it's working correctly:
1. Test manifest personalization:
1. Request the same content URL with different ad parameters
1. Verify that each request returns different ad insertions
1. Test segment caching:
1. Check CDN metrics for segment cache hit ratio (should be greater than 90%)
1. Monitor origin traffic to confirm it's lower than direct delivery
1. Test playback performance:
1. Play content through your CDN from different locations
1. Verify smooth playback with no buffering issues
For comprehensive testing methodologies and advanced validation procedures, see [Testing and validation for CDN and MediaTailor integrations](cdn-integration-testing.md).
## Optimize CDN performance
After verifying your basic configuration, implement these optimizations to maximize performance and minimize costs:
### Monitor key performance metrics
Track these metrics to ensure optimal performance:
Cache hit ratio
**Target:** Greater than 90% for video segments
**Impact:** Higher ratios reduce origin load and improve viewer experience
**Monitor:** Check your CDN provider's analytics dashboard daily
Origin response time
**Target:** Less than 200ms for manifest requests
**Impact:** Faster manifest delivery reduces startup time for viewers
**Monitor:** Set up alerts for response times exceeding 500ms
Error rates
**Target:** Less than 0.1% for all requests
**Impact:** High error rates indicate configuration issues or origin problems
**Monitor:** Set up alerts for error rates exceeding 1%
### Fine-tune caching behavior
Adjust these settings based on your content characteristics and viewer patterns:
Segment TTL optimization
**Live content:** Use shorter TTL (1-4 hours) to ensure timely updates
**VOD content:** Use longer TTL (24-48 hours) to maximize cache efficiency
**Ad segments:** Consider shorter TTL (30 minutes to 2 hours) for frequently updated ad content
For comprehensive TTL recommendations and caching strategies across all MediaTailor workflows, see [Caching optimization for CDN and MediaTailor integrations](cdn-optimize-caching.md).
Geographic optimization
**Multi-region origins:** Configure origin selection based on viewer location
**Edge locations:** Enable additional edge locations in regions with high viewer concentration
**Failover:** Configure backup origins for high availability
### Optimize costs
Implement these strategies to reduce CDN costs while maintaining performance:
+ **Compression:** Enable gzip compression for manifest files to reduce bandwidth usage
+ **Purging strategy:** Implement selective cache purging instead of full cache clears
+ **Traffic analysis:** Review traffic patterns monthly to identify optimization opportunities
+ **Tier selection:** Use appropriate CDN service tiers based on your performance requirements
## Troubleshoot third-party CDN issues
CDN configuration issues typically manifest as either ad personalization problems or performance degradation. Use this systematic approach to identify and resolve the most common issues that affect MediaTailor ad delivery.
Most troubleshooting can be completed within 15-30 minutes by checking the specific symptoms and applying the corresponding solutions.
If viewers experience problems with ad delivery or playback quality, use this guide to identify and resolve common CDN configuration issues:
Akamai: Cached manifests
**Symptom:** Viewers see identical ads even when you configure different targeting parameters.
**Solution:** Verify that you applied the **No Store** caching option to manifest paths.
Also verify that you included query parameters in the cache key.
Fastly: Incorrect cache keys
**Symptom:** Viewers experience inconsistent ad personalization.
Viewers might also see ads intended for other viewers.
**Solution:** Verify that you configured the **Forward** settings to include all query parameters in the cache key.
General: High origin traffic
**Symptom:** Your origin servers experience unexpectedly high traffic
**Solution:** Verify segment caching settings and time-to-live (TTL) values.
Check cache hit ratios in your CDN metrics.
General: Playback errors
**Symptom:** Viewers experience buffering or playback failures
**Solution:** Check CDN routing rules and origin health.
Verify that all required headers are being forwarded correctly.
**Note**
If these solutions don't resolve your issue, check your CDN provider's documentation. You can also contact their support team for additional troubleshooting steps.
For general CDN troubleshooting guidance, see [Troubleshoot issues with MediaTailor and CDN integration](cdn-troubleshooting.md).