Ashburn sits next to the transatlantic cable landings and within about 15 ms of New York, Toronto, Chicago and Atlanta. How it pairs with a European primary, why one TCP flow across the Atlantic cannot fill a big port, and what the GDPR says about putting EU data there.
Poland is the EU's fifth most populous country, and every Baltic capital and Kyiv sit within 9 ms of floor from Warsaw. For game servers, regional services and patch-day delivery that distance is the whole argument. The latency table, the sizing rules and when Warsaw is the wrong pick.
Marseille faces south and east: it is where 2Africa, PEACE and AAE-1 come ashore. For North Africa it is 650 to 800 km closer than Frankfurt; for the Gulf it is the European end of the cable. The latency table, the video and regional workloads that fit, and the limits.
For users in Romania, Bulgaria, Moldova and Serbia, a server in Frankfurt adds 15 to 20 ms to every round trip. Bucharest removes it at the same price, keeps the data in the EU, and is where our 96 TB storage servers live. The latency table, the workloads and the sizing.
Amsterdam and Frankfurt are under 4 ms apart, so for most of Europe the choice is a wash. At the edges it is not: the UK, Ireland, the Benelux and the Nordics lean Amsterdam. The latency table, the VPN and delivery workloads that suit it, and a sizing rule for each.
Frankfurt is the default European location, and usually the right one: one of the world's largest internet exchanges, and no major capital in the west or centre of the continent more than about 25 ms away. The latency table, the workloads that fit, and the cases where another city wins.
A handful of caching edges in front of one origin covers most of what a commercial CDN does for a European audience, at a fraction of the per-terabyte price. The architecture, the nginx configuration that does most of the work, how users reach the nearest edge, and where the do-it-yourself version loses.
The port is the easy part — it is lit in an afternoon. Then the machine behind it has to produce 12.5 gigabytes every second, and each layer between the disk and the wire gets a chance to be the reason it does not. The arithmetic, in the order it fails.
Both protocols get video from an encoder into your origin; neither is what viewers receive. Judged on that one job, they differ sharply under packet loss — and the SRT latency setting decides whether it helps at all. A comparison, with the pipeline around it.
Kernel settings are changeable; the distance between your server and your users is physics. Work out the latency floor from the map, understand why interconnection decides how close you get to it, and test from where the users actually are before committing.
One exit node is easy to specify and tells you nothing about the next fifty. Concurrency, throughput per session and oversubscription set subscribers per node; packet rate rather than cipher choice sets the ceiling; and country coverage wants a tiered fleet, not identical boxes.
Monthly transfer is the wrong starting point, because a port is a rate. Size from peak concurrency, per-unit bitrate and headroom — then check the cost per gigabit of each tier, because that curve is not monotonic and the cheapest gigabit is not where most people buy.