Internet Protocols

2 articles

Tech 15 Sep 2026 7 min read

QUIC Connection IDs Keep Sessions Across Address Changes

A network connection is often associated with addresses and ports. That works well while both endpoints keep the same network attachment, but mobile devices regularly move between Wi-Fi and cellular service, and NAT devices can replace an external UDP port while an application is still active. QUIC provides another identifier for the transport connection: the connection ID. A non-zero-length connection ID lets an endpoint associate incoming QUIC packets with existing connection state even when the packet arrives from a different IP address or UDP port.

QUIC Networking

Tech 14 Sep 2026 6 min read

TCP Fast Open Sends Data During Connection Setup

A conventional TCP connection separates setup from application traffic. The client sends a SYN, the server replies with SYN-ACK, and the client completes the three-way handshake with an ACK. Application data normally follows after that exchange has established the connection. For short transactions, that setup time can be a meaningful part of the total delay. A request may contain only a few hundred bytes, yet it still waits for a network round trip before the server can receive it through the established connection.

TCP Networking