> For the complete documentation index, see [llms.txt](https://clients.medianova.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://clients.medianova.com/products/performance-cdn/faqs.md).
# FAQs
## CDN Basics
What is a CDN?
A **Content Delivery Network (CDN)** is a globally distributed network of edge servers that delivers content from locations closer to users. Instead of every request reaching the origin server, the CDN caches and serves eligible content from the nearest Point of Presence (PoP), reducing latency and improving response times.
A CDN can deliver static assets, accelerate dynamic content, optimize video delivery, and help protect applications from traffic spikes and network-based attacks.
{% hint style="info" %}
**Learn more:**
* [Static Content Delivery](/products/performance-cdn/static-content-delivery.md)
* [Dynamic Content Acceleration](/products/performance-cdn/dynamic-content-acceleration.md)
{% endhint %}
How does a CDN work?
When a user requests content, the request is routed to the nearest Medianova edge server. If the requested object is already cached and still valid, the CDN delivers it immediately. Otherwise, the edge server retrieves the content from the origin, returns it to the user, and caches it according to the configured cache policy.
This process reduces origin traffic while improving response times and scalability for subsequent requests.
Who should use a CDN?
A CDN is suitable for any organization that delivers content over the internet and wants to improve performance, scalability, or availability.
Typical use cases include:
* Websites with visitors across multiple regions
* E-commerce platforms
* Media and streaming services
* APIs and SaaS applications
* Corporate websites
* Government and public services
Organizations with high traffic volumes or globally distributed users generally benefit the most from CDN deployment.
{% hint style="info" %}
**Learn more:**
* [Static Content Delivery](/products/performance-cdn/static-content-delivery.md)
* [Dynamic Content Acceleration](/products/performance-cdn/dynamic-content-acceleration.md)
* [Private CDN](/products/performance-cdn/private-cdn.md)
{% endhint %}
Why should I use a CDN?
A CDN helps improve application performance by serving content closer to users and reducing requests to the origin server. It also improves scalability during traffic peaks, reduces latency, and increases service availability through a distributed edge network.
Depending on your configuration, a CDN can also provide caching, TLS termination, DDoS mitigation, image optimization, and video delivery capabilities.
How does a CDN improve website performance?
A CDN improves website performance by reducing the distance between users and content. Frequently requested objects are served directly from edge servers instead of the origin, reducing network latency and origin load.
Additional optimizations such as HTTP/2, HTTP/3, compression, image optimization, connection reuse, and efficient cache management further reduce page load times. Together, these optimizations help improve user experience, especially for geographically distributed audiences.
## Caching
What is static content?
Static content consists of files that are delivered without being generated or modified for each request. Every user receives the same version of the content.
Common examples include:
* Images
* CSS files
* JavaScript files
* Fonts
* Downloadable files
* Videos
Because static content changes infrequently, it is well suited for CDN caching and can be served directly from edge servers.
{% hint style="info" %}
**Learn more:**
* [Static Content Delivery](/products/performance-cdn/static-content-delivery.md)
{% endhint %}
What is dynamic content?
Dynamic content is generated by the origin application in response to each request. The returned content may vary depending on application logic, user identity, location, session data, or request parameters.
Common examples include:
* Personalized dashboards
* Shopping carts
* User account pages
* Search results
* API responses
Dynamic content is typically retrieved from the origin, although some responses can also be cached when appropriate.
{% hint style="info" %}
**Learn more:**
* Dynamic Content Acceleration
{% endhint %}
Can dynamic content be cached?
Yes. Although dynamic content is often generated on demand, many dynamic responses can be cached when they are safe to reuse.
Examples include:
* Public API responses
* Product catalogs
* News feeds
* Frequently requested search suggestions
Whether a response is cached depends on the configured cache policy, cache headers, and application requirements. Personalized or user-specific content is generally not cached.
{% hint style="info" %}
**Learn more:**
* Dynamic Content Acceleration
{% endhint %}
What is the difference between browser cache and CDN cache?
Browser cache stores content on the user's device to avoid downloading the same resources repeatedly.
CDN cache stores content on distributed edge servers, allowing multiple users to receive cached content without contacting the origin server.
Both caching layers can work together. A browser may serve locally cached content, while the CDN reduces requests reaching the origin for users who do not already have the resource cached.
{% hint style="info" %}
**Learn more:**
* [Browser Cache](/products/performance-cdn/static-content-delivery/advanced-configuration/caching/browser-cache-rule.md)
* [Edge Cache Expiration](/products/performance-cdn/static-content-delivery/advanced-configuration/caching/edge-cache-expiration.md)
{% endhint %}
What happens during a cache miss?
A cache miss occurs when the requested object is not available in the CDN cache or the cached copy is no longer valid.
When this happens:
1. The CDN forwards the request to the origin server.
2. The origin returns the requested content.
3. The CDN delivers the response to the client.
4. If the response is cacheable, it is stored at the edge for future requests.
Subsequent requests may be served directly from the CDN until the cached content expires or is refreshed.
How long does content remain cached?
Content remains cached for the duration defined by the cache policy. This duration can be controlled by origin response headers, CDN configuration, or both.
When the cache lifetime expires, the CDN retrieves an updated copy from the origin before serving future requests. The appropriate cache duration depends on how frequently the content changes and how quickly updates need to become available.
{% hint style="info" %}
**Learn more:**
* [Browser Cache](/products/performance-cdn/static-content-delivery/advanced-configuration/caching/browser-cache-rule.md)
* [Edge Cache Expiration](/products/performance-cdn/static-content-delivery/advanced-configuration/caching/edge-cache-expiration.md)
{% endhint %}
## Content Delivery
What is the difference between Origin Pull and Origin Push?
Origin Pull and Origin Push define how content becomes available on CDN edge servers.
In an **Origin Pull** configuration, the CDN retrieves content from the origin only when it receives the first request. The content is then cached at the edge and served directly for subsequent requests until the cache expires.
In an **Origin Push** configuration, content is uploaded to the CDN before users request it. The CDN distributes the uploaded content across its edge network, making it immediately available for delivery.
Origin Pull is commonly used for websites and applications, while Origin Push is often used for pre-published media and downloadable content.
{% hint style="info" %}
Learn more: [Static Content Delivery](/products/performance-cdn/static-content-delivery.md)
{% endhint %}
What is the difference between streaming and progressive download?
With **progressive download**, the client downloads the media file over HTTP while playback begins after enough data has been received. The entire file is typically downloaded even if the viewer stops watching before the end.
With **streaming**, the media server or streaming platform delivers content in small segments during playback. The player requests only the segments it needs, enabling adaptive bitrate streaming and reducing unnecessary bandwidth consumption.
Streaming provides a better viewing experience for live events and long-form video content, while progressive download is suitable for simple media delivery.
{% hint style="info" %}
Learn more: [Video on Demand (VOD)](/products/performance-cdn/static-content-delivery/create-vod-resource.md)
{% endhint %}
How does adaptive streaming work?
Adaptive streaming divides a video into small segments and makes multiple quality levels available. During playback, the video player continuously measures network conditions and requests the most appropriate quality level for each segment.
If bandwidth decreases, the player switches to a lower bitrate to avoid buffering. If network conditions improve, it automatically switches back to a higher quality stream.
This approach provides smooth playback across different devices and network conditions while minimizing interruptions.
{% hint style="info" %}
Learn more: [Video on Demand (VOD)](/products/performance-cdn/static-content-delivery/create-vod-resource.md)
{% endhint %}
When should I use Video on Demand (VOD)?
Use **Video on Demand (VOD)** when users need to watch pre-recorded video content at any time rather than during a live broadcast.
Typical use cases include:
* Training and educational videos
* Media libraries
* Product demonstrations
* Corporate communications
* Entertainment platforms
VOD platforms commonly use adaptive streaming technologies such as HLS or MPEG-DASH to deliver the appropriate video quality based on each viewer's network conditions and device capabilities.
{% hint style="info" %}
Learn more: [Video on Demand (VOD)](/products/performance-cdn/static-content-delivery/create-vod-resource.md)
{% endhint %}
## Network & Routing
What is Anycast?
Anycast is a network routing technique in which the same IP address is announced from multiple geographically distributed locations. Internet routing protocols automatically direct each request to the most appropriate location based on network topology, routing policies, and current conditions.
CDNs commonly use Anycast to reduce latency, improve availability, and automatically distribute traffic across multiple edge locations.
How does CDN routing work?
When a user requests content, the request is directed to the most appropriate CDN edge server rather than being sent directly to the origin. Routing decisions are based on Internet routing protocols, network conditions, and the distribution of CDN edge locations.
After reaching an edge server, the CDN either serves cached content immediately or retrieves the requested content from the origin if it is not already available at the edge.
How does the CDN select the nearest edge server?
The CDN does not simply select the geographically closest server. Instead, Internet routing determines which Point of Presence (PoP) can be reached most efficiently.
Factors that influence edge selection include:
* Network topology
* BGP routing decisions
* Network congestion
* Link availability
* PoP health and capacity
As network conditions change, traffic may automatically be routed to a different edge location to maintain optimal performance and availability.
What is a Point of Presence (PoP)?
A **Point of Presence (PoP)** is a physical or virtual edge location where CDN servers cache and deliver content to nearby users.
Each PoP stores cacheable content, accepts client requests, and communicates with the origin server when necessary. By distributing PoPs across multiple regions, a CDN reduces latency, improves availability, and minimizes the distance that data must travel.
The number and geographic distribution of PoPs directly influence a CDN's global coverage and delivery performance.
## Security
Does a CDN improve security?
Yes. A CDN can improve the security of internet-facing applications by acting as a protective layer between clients and the origin server.
Depending on the configured services, a CDN can provide capabilities such as:
* TLS/SSL termination
* Web Application Firewall (WAF)
* DDoS mitigation
* Rate limiting
* Origin protection
* Request filtering
These features help reduce direct exposure of the origin infrastructure while allowing legitimate traffic to reach the application.
{% hint style="info" %}
**Learn more:**
* [Web Application Firewall (WAF)](/products/security/web-application-firewall-waf.md)
* [TLS/SSL](/products/security/ssl-tls-encryption.md)
* [Security](/products/security.md)
{% endhint %}
Does a CDN protect against DDoS attacks?
Yes. A CDN can help mitigate many types of Distributed Denial-of-Service (DDoS) attacks by absorbing and filtering malicious traffic across its distributed edge network before it reaches the origin.
Protection capabilities vary depending on the attack type and the enabled security services. DDoS mitigation is commonly combined with rate limiting, traffic filtering, and Web Application Firewall (WAF) rules to improve resilience against malicious traffic.
{% hint style="info" %}
**Learn more:**
* [DDoS Protection](/products/security/ddos-protection.md)
* [Rate Limiting](/products/security/rate-limiting.md)
* [Web Application Firewall (WAF)](/products/security/web-application-firewall-waf.md)
{% endhint %}
Does HTTPS work with a CDN?
Yes. A CDN supports HTTPS by terminating encrypted client connections at the edge using SSL/TLS certificates.
Depending on the deployment, the connection between the CDN and the origin can also be encrypted, allowing HTTPS to be maintained throughout the entire delivery path. This helps protect data in transit while preserving the performance benefits of edge delivery.
Medianova supports multiple certificate options, including shared and custom SSL/TLS certificates, depending on the resource type and deployment requirements.
{% hint style="info" %}
**Learn more:**
* [TLS/SSL](/products/security/ssl-tls-encryption.md)
* [SSL Certificates](/products/security/ssl-tls-encryption/upload-and-manage-ssl-certificates.md)
{% endhint %}
## Performance
How does a CDN improve SEO?
A CDN can contribute to SEO by improving website performance and availability. Faster page load times, reduced latency, and improved reliability help create a better user experience, which can positively influence search engine rankings.
While a CDN does not directly improve SEO, it supports many performance-related factors that search engines consider, such as page speed and Core Web Vitals.
{% hint style="info" %}
Learn more: [Static Content Delivery](/products/performance-cdn/static-content-delivery.md) , [Image Optimization](/products/performance-cdn/image-optimization-and-webp.md)
{% endhint %}
Does a CDN improve API performance?
Yes. A CDN can improve API performance by reducing network latency and optimizing the connection between clients and the origin.
Depending on the application, a CDN can cache cacheable API responses, reuse persistent origin connections, optimize TLS handshakes, and route requests through the nearest edge location. These optimizations can reduce response times and decrease the load on origin infrastructure.
The greatest performance improvements are typically achieved for cacheable or frequently requested API responses.
{% hint style="info" %}
**Learn More:** [Dynamic Content Acceleration](/products/performance-cdn/dynamic-content-acceleration.md)
{% endhint %}
Does a CDN improve mobile performance?
Yes. A CDN can improve mobile performance by delivering content from edge servers closer to mobile users, reducing latency across cellular and wireless networks.
Combined with features such as image optimization, compression, modern transport protocols, and efficient caching, a CDN helps reduce page load times and bandwidth consumption across a wide range of devices and network conditions.
These optimizations contribute to a faster and more consistent experience for mobile users.
{% hint style="info" %}
**Learn more:**
* [Image Optimization](/products/performance-cdn/image-optimization-and-webp/image-optimization.md)
* [Compression](/products/performance-cdn/static-content-delivery/advanced-configuration/compression.md)
{% endhint %}
## Enterprise
What is Private CDN?
A **Private CDN** is a dedicated content delivery infrastructure designed for a single organization rather than being shared with multiple customers.
Private CDNs provide greater control over network architecture, capacity planning, routing policies, security, and operational requirements. They are commonly used by organizations with high traffic volumes, strict compliance requirements, or predictable workloads.
{% hint style="info" %}
**Learn more:**
* [Private CDN](/products/performance-cdn/private-cdn.md)
{% endhint %}
What is the difference between Public CDN and Private CDN?
A **Public CDN** is a shared platform where multiple customers use the same globally distributed infrastructure. It is suitable for most websites, applications, and content delivery workloads.
A **Private CDN** is dedicated to a single organization. It provides exclusive infrastructure, allowing greater control over network design, capacity, security policies, and operational requirements.
The appropriate deployment model depends on factors such as traffic volume, performance objectives, compliance requirements, and operational needs.
When should I choose a Private CDN?
A Private CDN may be appropriate when your organization requires dedicated infrastructure or greater operational control.
Typical scenarios include:
* High and predictable traffic volumes
* Large-scale media delivery
* Strict security or compliance requirements
* Dedicated network capacity
* Custom routing or infrastructure policies
For most websites and applications, a Public CDN provides sufficient performance and scalability. A Private CDN is typically selected for enterprise workloads with specialized requirements.
{% hint style="info" %}
**Learn more:**
* [Private CDN](/products/performance-cdn/private-cdn.md)
* [Security](/products/security.md)
{% endhint %}
Can Medianova build a dedicated CDN infrastructure for my organization?
Yes. Medianova provides **Private CDN** solutions for organizations that require dedicated content delivery infrastructure.
Private CDN deployments are designed according to each organization's traffic profile, geographic coverage, security requirements, and operational objectives. Infrastructure, routing policies, and deployment architecture can be tailored to meet specific business and technical requirements.
For organizations evaluating a dedicated CDN deployment, the Medianova team can help determine the most appropriate architecture based on the intended workload.
**Learn more:**
* [Private CDN](/products/performance-cdn/private-cdn.md)
* [Contact Sales](/support-and-troubleshooting/contacting-customer-support.md)
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://clients.medianova.com/products/performance-cdn/faqs.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.