How private VLANs improve low latency for CDN and edge workloads

Private VLANs and low latency: A real-world snapshot from EU waves

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Modern infrastructure demands low latency. Whether you're deploying a CDN PoP, optimizing game servers, or building real-time analytics at the edge, milliseconds matter.

In early June 2025, we ran a manual sweep of round-trip latency across six of our major European data centers - Prague, Vienna, Frankfurt, Amsterdam, Paris, and London - all interconnected by FDC’s dedicated 100G/400G DWDM wave circuits. The results offer a useful snapshot of how private VLANs and direct wave connections can significantly cut down latency and jitter, even across international distances.

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Real latency data: what the EU snapshot tells us

This snapshot used native Junos ping in rapid mode, sending 20 ICMP echo packets per route. Results captured average RTT and gave insight into jitter and symmetry. No packet loss was detected during the test window.

Here’s a sample of the measured round-trip times:

• Frankfurt ↔ Amsterdam: ~6.6 ms
• Prague ↔ London: ~34–38 ms
• Amsterdam ↔ Paris: ~13 ms
• Vienna ↔ London: ~28 ms
• Paris ↔ London: ~10 ms

The best case, Frankfurt to Amsterdam, clocks in under 7 ms — consistent with a ~700 km direct fiber route and single-hop DWDM. Most intra-hub links fall well below the 25 ms design budget.

Jitter and burst latency were also low across the board, with only two routes (PRG ↔ VIE and PRG ↔ LON) showing max latency spikes near 40 ms. These are likely transient conditions and show no persistent congestion.

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Why this matters for CDN and edge deployments

Private VLANs built over dedicated optical waves offer several key advantages for latency-sensitive services:

• Predictability: With traffic isolated from the public internet, there's no interference from outside traffic.
• Symmetry: Over 80% of A→B and B→A measurements differed by less than 2 ms — crucial for real-time workloads.
• Stability: Minimal jitter ensures consistent experience for streaming, gaming, and real-time analytics.
• Reach: Even long-haul links like Prague ↔ London stayed within acceptable latency bounds.

If you're operating a CDN or deploying edge services in Europe, private VLANs are an essential part of your toolkit.

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📺 Watch: Micro-segmentation using Private VLANs

This recent video explains how private VLANs enable isolation, control, and micro-segmentation, all key to stable, low-latency workloads.

▶️ YouTube: Watch on YouTube

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TL;DR

• FDC’s private VLANs offer consistently low-latency links across major EU hubs.
• Most inter-data center routes fall between 8 ms and 22 ms.
• Best route (FRA ↔ AMS) achieved ~6.6 ms, ideal for CDN and edge PoPs.
• Jitter and asymmetry were minimal, supporting high-performance workloads.

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Closing Thoughts

Private VLANs are more than a networking luxury, they’re an essential building block for high-performance infrastructure. Whether you’re running a CDN, deploying real-time analytics, or delivering low-latency game servers, the kind of stability and speed seen in the EU snapshot is only possible when your traffic isn’t sharing the road with everyone else.

FDC makes this easy: you can add a private VLAN between our EU data centers for just $100/month per connection.

Contact us to set up your private connection →