Interview Q&A / Computer Networks
Computer Networks interview questions
What happens when you open a website, TCP vs UDP, DNS and HTTP.
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- What does a UDP header contain, and how big is it?
A UDP header is 8 bytes with four 16-bit fields: source port, destination port, length, and checksum. A TCP header is at least 20 bytes. That small size is part of why UDP is light.
BeginnerQuick answer1 min read - What is a port number, and how is it different from an IP address?
An IP address identifies a machine on a network. A port number (0 to 65535) identifies which program on that machine should receive the data. Together they pick out one exact conversation endpoint.
BeginnerQuick answer1 min read - When would you choose UDP over TCP? Give real examples.
Choose UDP when speed and low delay matter more than perfect delivery, or when the app wants its own control: live video calls, online games, DNS lookups, and streaming. Old data is useless in real time, so waiting for a retransmission is worse than skipping it.
BeginnerQuick answer1 min read