Application services differ from network services in several key ways, including • Network services provide generic transport mechanisms useable by any application. • Application services provide specific transport services optimized for a specific application or purpose. • Network services run on top of IP, which abstracts different kinds of physical transport. • Application services run […]
Opening a web page almost seems like magic—typing in a single Uniform Resource Locator (URL) results in images, videos, text, and other graphic elements combined into a page within a web browser. The magic under the hood includes • The Hypertext Markup Language (HTML) and Cascading Style Sheets (CSS). These elements describe the content and […]
This chapter considered the five most common transport services provided by IP networks: • IPv4 • IPv6 • UDP • TCP • QUIC IPv4 and IPv6 separate the physical and logical transmission of data so IP networks can work across many physical networks. UDP provides a simple data transport method ideal for situations where small […]
In Figure 14-5, what if • B’s best path to F is through C? • C’s best path to F is through E? • E’s best path to F is through D? • D’s best path to F is through B? Figure 14-5 Control Plane Routing Loop Why would router E point toward D to […]
TCP has several significant limitations, including • A three-way handshake is required for all connections, even between previously connected hosts. • Multiple TCP sessions, each requiring a three-way handshake, are required to carry multiple data streams, as shown in Figure 14-11. • TCP does not automatically encrypt data. A second protocol, such as Transport Layer […]
Much of the data people use the modern Internet to access resides in data centers, and users access the data through the Hypertext Markup Language (HTML). Note Chapter 15, “Application Transport, ” discusses HTML and the Hypertext Transfer Protocol (HTTP). Content providers, such as search engines and social media networks, develop and manage some of […]
In the early 1970s, scientists and engineers began working on a new computer networking technology. They designed this technology around a basic three-layer model: • The physical layer would handle the physical process of carrying data between two interfaces. • The network layer would provide an interface between physical transports (there were many at the […]
A butterfly fabric is like a Clos fabric but has five stages instead of three. Figure 13-7 illustrates a small butterfly fabric. Note Some network engineers called a butterfly a five- stage Clos. For clarity, this book always calls a three-stage spine-and-leaf a Clos and a five-stage the design described in this section a butterfly. […]
