If you’ve come across the term “Dedicated Internet Access” while researching business connectivity, you’ve probably also seen it called an Internet Leased Line, an ILL, or just “DIA” — and it’s not always obvious whether these are different products or the same thing with different names. This is a plain-language explanation of what the term actually means, with no assumed background.
The Short Answer
Dedicated Internet Access and Internet Leased Line describe essentially the same thing: a private internet connection reserved exclusively for one customer, as opposed to a connection shared among many customers. “DIA” is the term used more often in enterprise/US-influenced terminology; “ILL” or “leased line” is more common in Indian and UK telecom usage. When a provider uses either term, ask what they mean by it — the words matter less than the actual specification underneath (covered below).
What Makes a Connection “Dedicated”
Most business and consumer internet connections are shared: your provider sells the same physical capacity to many customers on the same local segment, on the assumption that not everyone uses their full allocation at the same time (this is called contention). A dedicated connection removes that assumption entirely — the bandwidth you’re paying for is physically and contractually reserved for you alone, with a 1:1 contention ratio, from the provider’s network core to your premises.
How It Actually Works
A DIA/ILL circuit runs as a private path from the provider’s core network directly to your building, typically over dedicated fiber. Because that path isn’t shared, the provider can guarantee symmetrical speeds (upload equal to download) and attach a contractual, legally binding uptime commitment to it — something that’s structurally impossible on a shared connection, because the provider can’t control what other customers on that shared segment are doing at any given moment.
What You Typically Get With It
- 1:1 uncontended bandwidth — no sharing, no slowdown from other customers’ usage
- Symmetrical upload/download speeds — equal in both directions
- A contractual SLA — typically a defined uptime percentage with service credits if it’s missed (see our guide on how to read an internet SLA)
- A dedicated static IP address or subnet — for VPNs, hosted servers, and firewall rules (see our guide on static IP for business)
Who Actually Needs This
DIA/ILL makes the most sense where a connectivity gap has a direct, measurable cost: hosted ERP servers, manufacturing plants running SCADA or IoT telemetry, financial transaction systems, or any operation where “the internet was slow for an hour” translates into lost revenue rather than mild annoyance. For a full breakdown of when it’s worth the cost over standard business broadband, see our companion article, Leased Line vs. Broadband: What Gujarat Businesses Actually Need.
Frequently Asked Questions
Is “leased line” an older term that’s been replaced by “DIA”?
No — both terms are in active, current use; which one you hear more depends on the provider and region. They describe the same underlying product.
Is DIA the same as a “dedicated server” or “dedicated hosting”?
No — those terms refer to a physical server reserved for one customer, a completely different (though sometimes related) concept. DIA is about the internet connection itself, not the server hardware.
How is DIA priced compared to regular broadband?
It typically costs more per Mbps than shared broadband, priced for the dedicated bandwidth and contractual SLA rather than raw speed alone. See our guide on what actually drives leased line pricing in India for the specific variables involved.
To see full specifications and get a feasibility check for your location, visit our Internet Leased Line page or get in touch with our team.