1. Introduction to Networking , Instructor: Prof. Yan Chen
Advanced Sockets
Ashish Gupta
TA , Intro to Networking
Jan
Recital 2

2. The problem
You are a server and you want to listen for incoming connections as well as keep reading from the connections you already have.
Blocking
"block" is techie jargon for "sleep".
Lots of functions block.
accept() blocks.
All the recv() functions block

3. The select call
Enables you to deal with many clients at the same time
HOW ?
Monitors several sockets at the same time.
tell you which ones are ready for reading,
which are ready for writing,

4. A multi-person chat server
THE CODE
A multi-person chat server

5. A multi-person chat server
DEMO
A multi-person chat server

6. Important Points Accepting new connections via select
Client closes connection
Select returns “socket ready to read”
recv() will return 0.

7. 1-5 Transmission Delay Propagation Delay Message switched
Packet Switched
Circuit-switched vs Datagram
Differences in : Setup time, Store-and forward delay.

8. 2-13 Local Delay + Internet delay What is Beta and Delta here ?
caching