Tag: networking

Rate Limiting: Leaky Bucket vs Leaky Token Bucket

Similarity Both are used to control flow Differences Leaky Bucket Leaky bucket uses a queue to absorb a burst of requests & a constant set of requests are dequeued. If request overflows the queue capacity, the data is lost. Leaky Token Bucket Think of N semaphores as tokens. Leaky Token Bucket algorithm accepts a request till a semaphore is available.…

Supershort Intro to TLS

Transport Layer Security Client & Server use a stateful connection over TCP The connection is secured using a symmetric encryption Client indicates to server to use TLS Client usually use a different port (e.g.443) A primary use of TLS is to secure World Wide Web traffic between a website and a web browser encoded with the HTTP protocol. This use…

What is TCP BBR?

What is BBR A congestion control based on measuring the two parameters that characterize a path: bottleneck bandwidth and round-trip propagation time, or BBR. Why Use BBR? Better congestion control algorithm in TCP. No need to change the client. More effective in a high packet loss network! The classic TCP uses binary exponential backoff and makes requests slow. How BBR…

Internet Not working eh? How Ubuntu Resolves DNS?

Problem I upgraded my Ubuntu from 16.04 to 18. And the Internet stopped working. 😦 I tried rebooting interface, adding a new interface to ifconfig. But it did not help. What helped was an answer on AskUbuntu How it worked? The answer is in how Ubuntu lookup domains like http://www.google.com. Step 1 Check the domain in the local DNS, also…

NAT Protocol Simplified Explanation

The purpose of NAT protocol is to reduce usage of public IPs A host needs a public IP to connect to Internet If the host is part of a LAN with a gateway router, a host can use private IP to make requests to public Internet. The public Internet would see that all the requests are originating from a LAN…