What a dedicated internet line is, and how it differs
The value of a dedicated line is not peak bandwidth but dedicated capacity, controlled jitter and a contractual SLA. If your traffic is sensitive to packet loss and jitter — video conferencing, ERP, VoIP, cross-border trading — a faster broadband line will not fix it.
When companies first look at dedicated lines, the first question is usually "how many megabits". But the difference between a dedicated line and business broadband is not the peak number — it is whether anyone else is sharing the path.
1. Dedicated versus shared capacity
Broadband capacity is shared: one device serves a building, and the uplink is divided among all subscribers. At 8pm, when everyone streams video, your actual throughput drops. A speed test reporting 500 Mbps is measuring an off-peak peak.
A dedicated line (IPLC, MPLS access) provides committed capacity: 20 Mbps in the contract means 20 Mbps available throughout, regardless of time of day. That is why 20 Mbps of dedicated capacity often costs more than 500 Mbps of broadband — they are priced on different dimensions.
2. Latency and jitter are the real divide
Bandwidth determines how much you can move; latency and jitter determine how reliably it moves. Video calls freezing, ERP submissions hanging and VoIP dropouts are rarely bandwidth problems — they are jitter and packet loss.
Public internet routing is best-effort: reachability is guaranteed, path stability is not. The same destination may route through a different international gateway tomorrow, and latency jumps from 30 ms to 200 ms. A dedicated line fixes the path and applies QoS queues, holding jitter in single-digit milliseconds.
3. Routing is where cross-border breaks
Accessing Hong Kong or overseas servers from mainland China over the public internet means traversing international gateways, which congest at peak hours. A China–Hong Kong IPLC is a point-to-point circuit that bypasses public internet gateways entirely, so peak-hour congestion does not apply.
4. An SLA decides who is accountable
Broadband has no SLA — you queue for repair. Enterprise lines typically commit to availability (e.g. 99.9%) and response times, with credits if missed. That is not paperwork: it means the carrier has monitoring, spares and on-duty engineers on the other side.
5. When to buy one
- Under 10 staff, browsing and email only: business broadband is enough.
- Cross-border operations, overseas SaaS or self-hosted servers: at least one modest dedicated line as primary, broadband as backup.
- Multiple branches needing HQ ERP/OA access: MPLS VPN or SD-WAN, not a separate broadband line per site.
- Zero tolerance for downtime (trading, healthcare, production lines): dual dedicated lines with automatic failover.
6. A common misconception
"Once we have a dedicated line we don't need firewalls or optimisation" — no. A dedicated line fixes link quality, not application performance. If the server is slow, pages are not cached or queries are unindexed, a dedicated line just makes the slowness consistent.
The right sequence: identify whether the bottleneck is the link, the server or the application, then decide whether to invest in a line. Before quoting, we typically look at a week of MTR and packet-loss data.
Frequently asked questions
- Is a dedicated line always faster?
- Not necessarily. For bulk downloads, high-bandwidth broadband can peak higher. A dedicated line wins on committed capacity, low jitter and SLA — which matters for video, ERP and cross-border transactions.
- Is 20 Mbps of dedicated capacity enough?
- It depends on concurrency and workload. 20 Mbps dedicated typically supports 30–50 office users with ERP access. Heavy file transfer or multi-site video conferencing needs a measured assessment first.
- How does a dedicated line relate to VPN?
- A dedicated line is a committed path; a VPN is an encrypted tunnel over a path. You can run VPN over a dedicated line for encryption, or run VPN over broadband for low-cost connectivity where stability depends on the public internet.