CS 436 1-9

Protocols that are part of a distributed network application.

Application Layer

Time spent waiting in packet buffers for link transmission.

Queuing Delay

Transfer of data between neighboring network devices.

Link Layer

Delivery of datagrams from a source host to a destination host (typically).

Network Layer

Transfer of a bit into and out of a transmission media.

Physical Layer

Time needed to perform an integrity check, lookup packet information in a local table and move the packet from an input link to an output link in a router.

Processing Delay

Time need for bits to physically propagate through the transmission medium from end one of a link to the other.

Propagation Delay

Time spent transmitting packets bits into the link.

Transmission Delay

Transfer of data between one process and another process (typically on different hosts)

Transport Layer

1.4-2 Computing Packet Transmission Delay (1). Suppose a packet is L = 1500 bytes long (one byte = 8 bits), and link transmits at R = 1 Gbps (i.e., a link can transmit bits 1,000,000,000 bits per second). What is the transmission delay for this packet? a) .000012 secs b) .00012 secs c) .0000015 secs d) .0015 secs e) 666,666 secs

a) .000012 secs

1.4-6 Computing throughput: a simple scenario. What is the maximum throughput achievable between sender and receiver in the scenario shown below? a) 1.5 Mbps b) 10 Mbps c) 11.5 Mbps

a) 1.5 Mbps

1.1-1 What is the Internet? Which of the following descriptions below correspond to a "nuts-and-bolts" view of the Internet? a) A collection of billions of computing devices, and packet switches interconnected by links. b) A platform for building network applications. c) A "network of networks". d) A place I go for information, entertainment, and to communicate with people. e) A collection of hardware and software components executing protocols that define the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on the transmission and/or receipt of a message or other event.

a) A collection of billions of computing devices, and packet switches interconnected by links. c) A "network of networks". e) A collection of hardware and software components executing protocols that define the format and the order of messages exchanged between two or more communicating entities, as well as the actions taken on the transmission and/or receipt of a message or other event.

1.3-1 Routing versus forwarding. Choose one the following two definitions that makes the correct distinction between routing versus forwarding. a) Forwarding is the local action of moving arriving packets from router's input link to appropriate router output link, while routing is the global action of determining the source-destination paths taken by packets. b) Routing is the local action of moving arriving packets from router's input link to appropriate router output link, while forwarding is the global action of determining the source-destination paths taken by packets.

a) Forwarding is the local action of moving arriving packets from router's input link to appropriate router output link, while routing is the global action of determining the source-destination paths taken by packets.

1.1-3 What is a protocol? Which of the following human scenarios involve a protocol (recall: "Protocols define the format, order of messages sent and received among network entities, and actions taken on message transmission, receipt")? a) One person asking, and getting, the time to/from another person. b) A person reading a book. c) A person sleeping. d) Two people introducing themselves to each other. e) A student raising her/his hand to ask a really insightful question, followed by the teaching acknowledging the student, listening carefully to the question, and responding with a clear, insightful answer. And then thanking the student for the question, since teachers love to get questions.

a) One person asking, and getting, the time to/from another person. d) Two people introducing themselves to each other. e) A student raising her/his hand to ask a really insightful question, followed by the teaching acknowledging the student, listening carefully to the question, and responding with a clear, insightful answer. And then thanking the student for the question, since teachers love to get questions.

1.1-2 What is the Internet (2)? Which of the following descriptions below correspond to a "services" view of the Internet? a) A collection of billions of computing devices, and packet switches interconnected by links. b) A platform for building network applications. c) A "network of networks". d) A place I go for information, entertainment, and to communicate with people.

b) A platform for building network applications. d) A place I go for information, entertainment, and to communicate with people.