Metro Ethernet vs. Site-to-Site VPN: When to Switch
A VPN tunnel between two internet circuits is the cheap way to connect offices. Here are the specific signs it has stopped being the right one.
By SilverStar Internet
Connecting two offices with a site-to-site VPN is inexpensive, well understood, and runs on equipment you probably already own. For a lot of organizations it is genuinely the right answer, and it stays the right answer for years. But it has a distinct set of limits, and they tend to arrive quietly rather than all at once.
The first limit is throughput. A VPN tunnel can only move data as fast as the slower of the two internet circuits it rides on, and encryption overhead on both firewalls takes a further cut. Sites that felt fine when they were exchanging documents start struggling when they begin replicating storage or syncing databases.
The second is consistency. Traffic between your offices takes whatever path the internet chooses that morning, across networks nobody in your organization controls. Latency drifts, and applications that are sensitive to it, remote desktop, VoIP, database queries against a central server, feel different on different days without anything on your end having changed.
The third is accountability, and it is the one that wears teams down. When performance between sites degrades, you have two internet providers and at least one firewall vendor in the picture, and each can plausibly point at the others. Root-causing an intermittent problem across that boundary is genuinely difficult.
Metro Ethernet addresses all three by changing the underlying model. Your locations sit on a private Layer 2 network with committed bandwidth on an engineered path, and no public internet in between. Sites behave like one LAN, with no tunnel to build, monitor, or rebuild. Because one provider owns the circuit end to end, there is one number to call.
The common trigger points are worth naming: VPN throughput becomes a bottleneck, inter-site latency starts affecting how software feels, troubleshooting keeps turning into a dispute between carriers, or you begin moving storage replication, database sync, or imaging files between locations. Any one of those is a reasonable moment to price the alternative. A frequent middle path is a hybrid: private Ethernet between sites for internal traffic, plus dedicated internet access at each location for cloud and public traffic.