Tag

tcp

14 articles

Jul 13, 2026 Head-of-Line Blocking and the Transport Gap QUIC Was Built to Fill Why one lost TCP segment stalls every multiplexed request on a connection, and which parts of that coupling a UDP-based transport can actually remove. internet protocols
May 11, 2026 The Effective Window: Congestion Window, Receive Window, and Buffers Why three independent limits govern how much a TCP sender may have outstanding, how the congestion window grows and collapses, and which limit binds in practice. networking
Apr 16, 2026 Network Path Continuity Across a Migration Moving a guest changes the port its frames egress from. Switch forwarding tables, ARP caches, and in-flight TCP segments all have to be re-pointed, and the guest must not observe a reset connection. virtualization
Jan 27, 2026 Advertised Windows and Zero-Window Probing What the receive window field promises, how the receiver computes the value it advertises, and how a sender recovers when the peer advertises zero and then forgets to reopen. networking
Oct 9, 2025 Connection State Transitions and the TIME_WAIT Hold Why closing a TCP connection takes four segments rather than two, what TIME_WAIT protects against, and why the state exists on the side that closed first. networking
Jul 17, 2025 SYN Cookies and the Cost of Half-Open Connections How a server avoids storing state for every handshake attempt by encoding the connection parameters into the initial sequence number, and what the encoding gives up. networking
Jun 5, 2025 SACK Blocks and the Retransmission Queue How selective acknowledgement turns a cumulative ACK into a map of received ranges, why the sender keeps a scoreboard, and what the option length limit costs. networking
May 7, 2025 AIMD Congestion Control and the Collapse It Prevented Why additive increase with multiplicative decrease converges to a fair operating point, how the window is discovered without measuring the network, and where the control loop breaks. computing history
Sep 22, 2024 Slow Start: Exponential Probing and the Initial Window Problem A new connection has no estimate of path capacity, so it doubles its window each round trip until a threshold or a loss. The cost is a burst that a small buffer cannot absorb. networking
Aug 21, 2024 Ack Clocks and the Congestion Window: How a Sender Infers Available Capacity Why a TCP sender measures the path with returning acknowledgements instead of a timer, how the congestion window combines with the receive window, and what a stalled clock does to the estimate. networking
Jul 6, 2024 Retransmission Timeout Estimation and Karn's Algorithm Why the retransmission timer is computed from a smoothed round-trip estimate plus a variance term, and why timing a retransmitted segment corrupts the estimate. networking
Mar 1, 2024 Nagle's Algorithm and the Delayed Acknowledgement Deadlock Why coalescing small writes and batching acknowledgements interact badly, how the 40 ms delay arises, and which socket options disable each mechanism. networking
Nov 11, 2023 The Accept Loop: From listen() to an Accepted Connection What the kernel does between the TCP handshake and a readable socket, why listen() takes a backlog argument, and how accept wakeups distribute work across processes. backend systems
Dec 15, 2021 Sequence Numbers and the Sliding Window Arithmetic How a 32-bit byte counter replaces per-byte bookkeeping, why the window variables are indices into a modular sequence space, and where the arithmetic breaks. networking