What is RTT in CDN context?

RTT (Round-Trip Time) is the time it takes to send a request to a CDN server and receive a response. It is measured in milliseconds and indicates the network's response speed.

What is the difference between TTFB and RTT?

TTFB (Time To First Byte) measures the time from sending an HTTP request until receiving the first byte of the response. RTT measures the complete data exchange cycle at the network level. TTFB is usually greater than RTT because it includes the server's request processing time.

What Availability metric is considered good for CDN?

For professional CDN providers, an Availability (uptime) rate of 99.9% or higher is considered standard. Market leaders achieve 99.99% or even 99.999% availability.

TTFB of EdgeCenter: first response speed

How much time passes between a request and the first byte from EdgeCenter?

Все CDNvideo EdgeCenter Curator Megafon MWS CDN

RTT TTFB Throughput Availability

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EdgeCenter — a Russian CDN provider and cloud platform. In addition to content delivery, it offers DDoS protection, cloud hosting, and DNS services. The infrastructure is built on Anycast routing and is actively expanding across Russian regions and the CIS. Targeted at technology companies and projects with high fault-tolerance requirements. EdgeCenter is actively expanding its geographic footprint, including in CIS regions. When a new node comes online, TTFB in the corresponding region drops sharply — this is clearly visible on the historical chart. If your audience is located in the provider's actively growing regions, TTFB will improve over time.

Dynamics of average connection time

Cities with high TTFB

Providers with high TTFB

What is TTFB and why measure it?

TTFB (Time To First Byte) — the time from sending a request to receiving the first byte of the server's response. Includes RTT, TLS handshake, and CDN-side request processing time. TTFB directly affects:

page load speed as assessed by Google (Core Web Vitals)
website rankings in search results
the user's perception of site speed

Google recommends keeping TTFB below 800 ms. Values above this threshold negatively impact search rankings.

What do the TTFB charts show?

Average connection time trend chart (HTTP/HTTPS) — the difference between HTTP and HTTPS reflects the overhead of the TLS handshake. A large gap between the lines indicates a suboptimal SSL configuration on the provider's edge servers.
Cities with high TTFB — locations where the CDN server processes requests slowly. May indicate insufficient capacity at regional nodes or frequent cache misses.
Providers with high TTFB — a comparative response speed ranking. Low TTFB correlates with better search rankings and higher conversion rates.