Marcin Jahn | Dev Notebook
  • Home
  • Programming
  • Technologies
  • Projects
  • About
  • Home
  • Programming
  • Technologies
  • Projects
  • About
  • An icon of the Networking section Networking
    • HTTP Protocol
    • OSI Model
    • TCP Procol
    • UDP Protocol
    • WebSocket
    • HSTS
    • DNS
    • Server Name Indication
    • gRPC
  • An icon of the Security section Security
    • OAuth2
      • Sender Constraint
    • Cryptography
      • Cryptography Basics
    • TPM
      • Overiew
      • TPM Entities
      • TPM Operations
  • An icon of the Linux section Linux
    • Gist of Linux Tooling
    • Unknown
    • SELinux
    • Containers
    • Bash Scripting
    • Linux From Scratch
    • Networking
  • An icon of the Kubernetes section Kubernetes
    • Meaning and Purpose
    • Cluster
    • Dev Environment
    • Kubernetes API
    • Objects
    • Pods
    • Scaling
    • Events
    • Storage
    • Configuration
    • Organizing Objects
    • Services
    • Ingress
    • Helm
  • An icon of the Observability section Observability
    • Tracing
  • An icon of the Databases section Databases
    • ACID
    • Glossary
    • Index
    • B-Tree and B+Tree
    • Partitioning and Sharding
    • Concurrency
    • Database Tips
  • An icon of the SQL Server section SQL Server
    • Overview
    • T-SQL
  • An icon of the MongoDB section MongoDB
    • NoSQL Overview
    • MongoDB Overview
    • CRUD
    • Free Text Search
  • An icon of the Elasticsearch section Elasticsearch
    • Overview
  • An icon of the Git section Git
    • Git
  • An icon of the Ansible section Ansible
    • Ansible
  • An icon of the Azure section Azure
    • Table Storage
    • Microsoft Identity
  • An icon of the Google Cloud section Google Cloud
    • Overview
  • An icon of the Blockchain section Blockchain
    • Overview
    • Smart Contracts
    • Solidity
    • Dapps
  • Home Assistant
    • Home Assistant Tips
  • An icon of the Networking section Networking
    • HTTP Protocol
    • OSI Model
    • TCP Procol
    • UDP Protocol
    • WebSocket
    • HSTS
    • DNS
    • Server Name Indication
    • gRPC
  • An icon of the Security section Security
    • OAuth2
      • Sender Constraint
    • Cryptography
      • Cryptography Basics
    • TPM
      • Overiew
      • TPM Entities
      • TPM Operations
  • An icon of the Linux section Linux
    • Gist of Linux Tooling
    • Unknown
    • SELinux
    • Containers
    • Bash Scripting
    • Linux From Scratch
    • Networking
  • An icon of the Kubernetes section Kubernetes
    • Meaning and Purpose
    • Cluster
    • Dev Environment
    • Kubernetes API
    • Objects
    • Pods
    • Scaling
    • Events
    • Storage
    • Configuration
    • Organizing Objects
    • Services
    • Ingress
    • Helm
  • An icon of the Observability section Observability
    • Tracing
  • An icon of the Databases section Databases
    • ACID
    • Glossary
    • Index
    • B-Tree and B+Tree
    • Partitioning and Sharding
    • Concurrency
    • Database Tips
  • An icon of the SQL Server section SQL Server
    • Overview
    • T-SQL
  • An icon of the MongoDB section MongoDB
    • NoSQL Overview
    • MongoDB Overview
    • CRUD
    • Free Text Search
  • An icon of the Elasticsearch section Elasticsearch
    • Overview
  • An icon of the Git section Git
    • Git
  • An icon of the Ansible section Ansible
    • Ansible
  • An icon of the Azure section Azure
    • Table Storage
    • Microsoft Identity
  • An icon of the Google Cloud section Google Cloud
    • Overview
  • An icon of the Blockchain section Blockchain
    • Overview
    • Smart Contracts
    • Solidity
    • Dapps
  • Home Assistant
    • Home Assistant Tips

WebSocket

WebSocket surfaced in the era of HTTP/1.1. The basic idea is to enable bi-directional communication between the client and the server under a single TCP connection. Instead of relying on the traditional request-response model, under WebSocket both parties can send messages freely.

SignalR

WebSocket is one of the ways how SignalR transfers data. There are also other transport protocols supported, but WebSocket is the preferred one.

Use cases:

  • chatting
  • currencies exchange
  • live feed of a sports event
  • gaming

Establishing Connection

After the “normal” TCP connection gets established, the client has to send a GET (UPGRADE) request that asks the server to switch to WebSocket. The server responds with 101 (Switching Protocols). After that, both parties can communicate via WebSocket.

Here’s an example of how the upgrade looks like in the HTTP protocol (taken from the Wikipedia):

Client request (just like in HTTP, each line ends with \r\n and there must be an extra blank line at the end):

GET /chat HTTP/1.1
Host: server.example.com
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Protocol: chat, superchat
Sec-WebSocket-Version: 13
Origin: http://example.com

Server response:

HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Accept: HSmrc0sMlYUkAGmm5OPpG2HaGWk=
Sec-WebSocket-Protocol: chat

Sources

  • Wikipedia
←  UDP Protocol
HSTS  →
© 2023 Marcin Jahn | Dev Notebook | All Rights Reserved. | Built with Astro.