Data Encoding - ue22-p25-backend

Is layer 4 sufficient, or do we need something else?

With TCP or UDP we can do our data transfers between applications

In your opinion is it all good then or do we need something else?

🔎 Let’s look at a concrete example 🔎

A lock 🔒¶

Nothing standard in my data exchanges 😵‍💫

I created my own logic

but it’s ~~maybe~~ certainly not in the eyes of others.

A bit of standardization wouldn’t hurt ...

The big question that can arise is

in what format is it relevant to exchange data ❓

The OSI model does not really specify a data format other than saying it is binary 🤨

Layer 6 specifies things a bit in reality but it gives a fairly broad spectrum actually

😩 How do we do if we want to transmit

a packet of structured but heterogeneous data?

For example, a person’s information:

Name, First name, Date of birth, number of children, ...

Via Python 🐍 it’s easy!

import json
data = dict(name="jean", age=1)
serialized = json.dumps(data)
# serialized is now a string

import json
serialized = '{"name": "jean", "age": 1}'
data = json.loads(serialized)
# data is now a dictionary

This is where concrete things begin 🥳

Layer 7 = Application layer

Each "category" of application then specifies:

How communications are made between the client and the application

message format, expected content, ...

We talk about protocol, for example: