Suggest an editImprove this articleRefine the answer for “At what layer does TCP operate?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**TCP (Transmission Control Protocol)** operates at the OSI transport layer (layer 4, Transport Layer). **Key point:** it provides reliable data delivery, connection establishment via a 3-way handshake, and flow and congestion control.Shown above the full answer for quick recall.Answer (EN)Image## **TCP operates at the OSI transport layer (layer 4).** --- ## Detailed explanation **TCP (Transmission Control Protocol)** is a protocol that provides: - reliable data delivery - connection establishment (3-way handshake) - segment order control - error control - flow and congestion control - working with ports All these functions correspond exactly to the **OSI transport layer - L4 (Transport Layer)**.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.