CIR \xE2\x80\x94 Committed Information Rate \xE2\x80\x94 is one of the most important terms on a business internet quote, and one of the least explained. It's the line between bandwidth you're promised and bandwidth you only might get.
What CIR Means
The CIR is the minimum bandwidth the carrier guarantees you'll always have available, backed by the contract. On a dedicated circuit, the CIR equals your full speed \xE2\x80\x94 you get what you pay for, all the time. On best-effort broadband, there's effectively no CIR; you get "up to" a speed that's shared and not guaranteed.
Why It Matters
- Predictable performance: full CIR means no peak-hour slowdowns from shared congestion.
- It backs your SLA: guaranteed bandwidth is what makes uptime/quality commitments meaningful.
- It justifies DIA pricing: you're paying for the guarantee, not just the number.
On a quote, ask: "Is this the committed information rate, or a best-effort maximum?" A 100 Mbps full-CIR circuit is a different product \xE2\x80\x94 and price \xE2\x80\x94 than 100 Mbps best-effort. See why \"up to\" speeds aren't what you get.
Match CIR to the Site
Critical sites want full CIR; a back office may be fine with best-effort. Paying for guaranteed bandwidth where you don't need it is overbuying. We help you choose and compare on true terms. See DIA vs. dedicated fiber and DIA.
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