HTTP (Hypertext Transfer Protocol) is the foundation of the internet. It is used to load web pages, stream videos, and allow applications to fetch data. As a result of the widespread adoption of new protocols by companies like Google and Meta, it is estimated that a significant portion of internet traffic uses HTTP/3. In this article, we will explore the background of HTTP/3, the problems it solves, how it works, the reasons for its rapid adoption, and any outstanding challenges.

Why Do We Need HTTP/3?

Network protocols describe how data is communicated between two entities on a network (usually a user device and a web server). Because multiple companies develop software for networks, communication protocols must be standardized so that all software can work together. In other words, they need to understand each other by following the same rules.

In practice, we do not use one single protocol but rather a stack of protocols that work together. Each protocol in the stack has its own functionality and rules (see Figure 1). This design provides flexibility and reusability; we can use the exact same HTTP logic regardless of whether we are using Wi-Fi, a wired connection, or 4G.

Many of the early internet protocols were standardized in the 1980s and 1990s, meaning they were designed with the needs and limitations of decades ago in mind. While some of these protocols have stood the test of time, others are showing their age. Most of these problems can be worked around with clever tricks, but some are more difficult to avoid. The biggest offender is the Transmission Control Protocol (TCP), which is responsible for making sure data is sent and received reliably over the internet.

Why TCP Is No Longer Good Enough for the Modern Web

HTTP/1.1 and HTTP/2 are built on top of TCP. Specifically, a TCP connection must be established before HTTP requests and responses can be exchanged between client and server. Over the years, there have been many efforts to update TCP and solve some inefficiencies – for example, TCP sees web pages as single files instead of collections of hundreds of independent files. While some of these updates have been successful, most of the more transformative updates (such as TCP multipath and TCP FastOpen) have taken almost a decade to land in the public internet.

The primary challenge with evolving TCP is that there are millions of devices on the internet, each with its own implementation of the TCP protocol. Besides the obvious devices like our phones, laptops, and servers, there are also other types of middleboxes: routers, firewalls, load balancers, and so on. This means that in order to update TCP, we need to wait for the majority of these devices to update their own protocol implementations – a process that can take many years.

QUIC: The Solution

Faced with this almost unsolvable problem, the best solution is to introduce a completely new protocol to replace TCP. This new protocol is called QUIC (pronounced “quick”), which some jokingly refer to as TCP 2.0. The nickname is not undeserved, as QUIC takes many of the high-level features of TCP but makes some critical changes.

The biggest change is QUIC’s tight integration with the Transport Layer Security (TLS) protocol. TLS is responsible for encrypting sensitive data on the web; it is the “S” in HTTPS. In TCP, TLS only encrypts the actual HTTP data (see Figure 2); in QUIC, TLS encrypts most of the QUIC protocol itself. In other words, the metadata in TCP that is visible (and modifiable) to all middleboxes (such as packet numbers, connection close signals, etc.) is now private to only the client and server in QUIC.

In addition, because QUIC is more encrypted, it is much easier to make changes or add new features to it than to TCP – since only the clients and servers need to update, the middleboxes cannot decrypt and thus cannot interfere with the metadata anyway. This makes QUIC a much more forward-looking protocol that can adapt quickly to new challenges. Of course, this additional encryption also improves the overall security and privacy of the new protocol.

While QUIC is more efficient than TCP, it is important to note that it is not a complete replacement for TCP. QUIC is designed to be used for HTTP traffic, while TCP is used for many other types of traffic, such as email and file transfers.

Rapid Adoption of HTTP/3

HTTP/3 has been rapidly adopted by major websites and web browsers. Google and Meta (formerly Facebook) have both announced that they are using HTTP/3 on their websites, and Mozilla has announced that HTTP/3 will be enabled by default in Firefox.

There are several reasons for the rapid adoption of HTTP/3. First, HTTP/3 is more efficient than HTTP/2. It uses a new header compression algorithm called HPACK and a new transport protocol called QUIC that is designed to be more efficient than TCP. Second, HTTP/3 is more secure than HTTP/2. It uses TLS 1.3, which is the latest version of the TLS protocol. Third, HTTP/3 is more scalable than HTTP/2. It can support a larger number of concurrent connections.

Outstanding Challenges for HTTP/3

HTTP/3 is still a relatively new protocol, and there are still some outstanding challenges that need to be addressed. One challenge is that HTTP/3 is not yet supported by all web browsers. Another challenge is that HTTP/3 requires the use of TLS 1.3, which is not supported by all web servers.

Despite these challenges, HTTP/3 is a major improvement over HTTP/2. It is more efficient, more secure, and more scalable. As more web browsers and web servers support HTTP/3, it will become the dominant protocol for HTTP traffic.

Conclusion

HTTP/3 is the latest version of the HTTP protocol. It is designed to be more efficient, more secure, and more scalable than its predecessors. HTTP/3 is rapidly being adopted by major websites and web browsers, and it is likely to become the dominant protocol for HTTP traffic in the future.

基于tcp的协议有哪些

基于TCP（传输控制协议）的协议有很多，主要包括以下几种：

1. **HTTP（超文本传输协议）**：HTTP是一种用于传输HTML文档和相关资源的标准协议。它是一种基于TCP的应用层协议，通常与TCP端口80（HTTP端口）一起使用。HTTP使用TCP来建立连接，传输数据，并关闭连接。

2. **FTP（文件传输协议）**：FTP也是一种基于TCP的应用层协议，用于在客户端和服务器之间传输文件。FTP使用TCP端口21来建立连接，并在传输文件时使用不同的数据端口。 3

3. SMTP（简单邮件传输协议）

：SMTP是一种用于发送电子邮件的协议。它基于TCP，通常与TCP端口25一起使用。SMTP使用TCP连接来传输邮件，包括邮件头和邮件体。

：TELNET是一种用于远程登录到服务器的协议。它也基于TCP，通常与TCP端口23一起使用。TELNET通过使用TCP连接来传输文本数据，它允许用户在远程服务器上执行命令。

5. SSH（安全外壳协议）

：SSH是一种用于安全地连接到服务器的协议。它基于TCP，通过使用加密算法来保护数据传输，确保数据的安全性。

：RSYNC是一种用于在客户端和服务器之间同步文件和目录的协议。RSYNC通过TCP连接在客户端和服务器之间传输文件数据，以实现同步操作。

以上这些协议都是基于TCP的应用层协议，它们使用TCP来建立、维护和关闭连接，以传输数据。这些协议在互联网和局域网中广泛使用，用于网页浏览、文件传输、电子邮件发送、远程登录和数据同步等任务。同时，这些协议也经过了多年的发展和改进，以确保它们的安全性和效率。

internet实现了分布在世界各地的各类网络的互联，其最基础和核心的协议是？

internet实现了分布在世界各地的各类网络的互联，其最基础和核心的协议是HTTP协议。

HTTP协议（HyperText Transfer Protocol，超文本传输协议）是用于从WWW服务器传输超文本到本地浏览器的传输协议。

它可以使浏览器更加高效，使网络传输减少。它不仅保证计算机正确快速地传输超文本文档，还确定传输文档中的哪一部分，以及哪部分内容首先显示(如文本先于图形)等。

HTTP是客户端浏览器或其他程序与Web服务器之间的应用层通信协议。在Internet上的Web服务器上存放的都是超文本信息，客户机需要通过HTTP协议传输所要访问的超文本信息。

HTTP包含命令和传输信息，不仅可用于Web访问，也可以用于其他因特网/内联网应用系统之间的通信，从而实现各类应用资源超媒体访问的集成。

扩展资料

安全性更高的https协议：

HTTPS（全称：Hyper Text Transfer Protocol over Secure Socket Layer 或 Hypertext Transfer Protocol Secure，超文本传输安全协议），是以安全为目标的HTTP通道，简单讲是HTTP的安全版。

即HTTP下加入SSL层，HTTPS的安全基础是SSL，因此加密的详细内容就需要SSL。 它是一个URI scheme（抽象标识符体系），句法类同http:体系。

用于安全的HTTP数据传输。https:URL表明它使用了HTTP，但HTTPS存在不同于HTTP的默认端口及一个加密/身份验证层（在HTTP与TCP之间）。

这个系统的最初研发由网景公司(Netscape)进行，并内置于其浏览器Netscape Navigator中，提供了身份验证与加密通讯方法。现在它被广泛用于万维网上安全敏感的通讯，例如交易支付方面。