Chapter 1 Flashcards
(32 cards)
How are end systems connected together?
Connected by a network of communication links and packet switches
What is a transmission rate measured by?
bits/second
What is data with a header added to it?
A packet
What are the 2 most important protocols in the Internet
Transport Control Protocol (TCP) and Internet Protocol (IP)
Who develops Internet standards
Internet Engineering Task Force (IETF)
WHat are the IETF’s standards documents called
request for comments (RFCs)
What are distributed applications
Applications that involve multiole end systems that exchange data with each other
What does a socket interface do?
Specifies how a program running on one end system asks the Internet infrastructure to deliver data to a specific destination program running on another end system
What is the access network?
The network that physically connects an end system to the first router (edge router) on a path from the end system to any other distant end system.
What does the Digital Subscriber Line Access Multiplexer (DSLAM) do?
Seperates data and phone signals and sends data into the Internet.
What is Hybrid Fiber Coax?
When both fiber and coax cable are distributed from the neighborhood junction boxes.
Passive Opticla Network (PON)
A fiber splitting architecture that uses Optical Line Terminators (OLT) to deliver fiber to homes
What are the 2 forms of physical media?
- Guided media: waves are guided along the a solid media, such as a fiber-optic cable. UTP, or coax
- Unguided media: waves propogate in the atmosphere and in outer space, such as wireless LAN and digital satelite channel.
3 Broad groups of terrestrial channels are?
- Those that operate over very short distances (1 or 2 meters)
- Those that operate in local areas (10 to a few hundred meters)
- Those that operate in Wide areas (Tens of kilometers)
What are packets?
Long messages that are broken down into smaller chunks of data
What are the 2 predominant types of packet switches?
Routers and link-layer switches
What is store-and-forward transmission?
The packet switch must receive the entire packet before it can begin to transmit the first bit of the packet onto the outbound link.
What does the output queue (output buffer) do/
Stores packets that the router is about to send into that link.
What happens when arriving packets show up in a full buffer?
Packet loss is incurred.
Circuit Switched networks need?
Sources reserved for the duration of the communication.
- buffers
- link transmission rate
How is Frequency-division multiplexing applied to a link?
The frequency spectrum of a link is divided amoung the connections established across the link.
How is time divided using Time-division multiplexing?
Time is divided into frames of fixed duration, and each frame is divided into a fixed number of time slots.
Netork Structure 1
Interconects all of the access ISPs with a single global transit ISP
Network Structure 2
A two-tier hierarchy with gloabl transit providers residing at the top tier and access ISPs at the bottom tier
