Friday, June 18, 2021

Programming: Useful C or C++ Repositories

Repositories

System Design

Consistent hashing implementation using MD5 & RB trees (C++) - GITHUB link

Message queue implementation (C++) - GITHUB

Courses

MIT OCW C Course

Univ Wisconsin Madison OS Course

Saturday, May 8, 2021

WiFi: What is phy restart? Why is it important in dense RF environments?

 Phy restart on radio drivers typically means if the hardware (radio) is able to sync to the preamble of a packet which has a stronger signal strength while it is already in the process of decoding a packet.


This is typically useful in noisy environments to achieve a "capture effect", where the stronger packet is finally decoded at the rx. radio. If the radio does not support PHY restart then typically such a reception would result in a collision on the rx-side at the radio.

Monday, April 26, 2021

Linux: Nagle's Algorithm and How to Disable it

 Nagle's algorithm is a TCP optimization in the kernel stack that waits to aggregate small chunks of bytes before sending packets on a TCP connection. This approach optimizes the amount of frame overhead spent in sending very small packets over the network. However, when the data is fairly sporadic, this could also lead to an increase in the average delay experienced.


Nagle's algorithm running on a host can be disabled by:
echo 1 > /proc/sys/net/ipv4/tcp_low_latency