January 2023
Intermediate to advanced
458 pages
14h 16m
Chinese
Content preview from 可编程网络自动化
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4
｜
第
1
章
图 1-2：有什么变化？从 Telnet 变成了 SSH（来源：Big Switch Networks）
最初的
OpenFlow
规范正是
Martin Casado
亲身体验这些问题时的产物。随着业界将注意
力从低层协议更多地转向用例和解决方案，围绕
OpenFlow
的炒作已然消散
，当初的工
作成果成了整个业界的催化剂，使其重新思考应该如何构建、管理和运维网络。谢谢你，
Martin
。
换句话说，如果不是因为
Martin Casado
，可能也不会有这本书
，不过如今永远都不可能知
道答案了！
1.1.2
什么是软件定义网络
我们已经介绍了
OpenFlow
，但什么是软件定义网络（
SDN
）呢？两者是同一个东西吗？
说实话，
SDN
就像差不多十多年前的
“云”一样，我们知道有不同类型的“云”，比如
基础设施即服务（
Infrastructure
as a Service
，
IaaS
）、平台即服务（
Platform as a Service
，
PaaS
）以及软件即服务（
Software as a Service
，
SaaS
）。
使用参考示例和设计可以简化对于云的过去和现在的理解，但即使在这些术语出现之前，
也可以争辩说，当看到云的时候，你就知道了。这就跟我们现在与软件定义网络所处的境
况一样。尽管有很多定义，比如白盒网络就是
SDN
，或者网络设备支持
API
就是
SDN
，
但
真的
如此吗？好像也不尽然。
我们不再尝试给
SDN
下定义
，而是打算介绍一些经常被认为是
SDN
并出现在相关对话中
的技术和趋势。
网络行业发展趋势
｜
5
•
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.