Test 1

Question 1

cwnd

Answer 1

Congestion window. Assumed less than rwnd. AIMD. How big window can get

Question 2

rwnd

Answer 2

Sender limits unACKed (in-flight) data to rwnd value. Free buffer space

Question 3

EstimatedRTT

Answer 3

Estimated round trip time

Question 4

DevRTT

Answer 4

Safety margin.

Question 5

TimeoutInterval

Answer 5

EstimatedRTT + 4*DevRTT

Question 6

Data Plane

Answer 6

Physical forwarding

Question 7

Control plane

Answer 7

Routing logic - determines how datagram is routed from source to dest.

Question 8

Scheduling discipline

Answer 8

Choosing among queued packets to transmit.

Question 9

Network protocols

Answer 9

RIP, OSPF, BGP, IP, ICMP

Question 10

IPv6 -priority field

Answer 10

Identify priority among datagrams in flow

Question 11

Flow Label ipv6

Answer 11

Identify data grams in the same flow

Question 12

Next head ipv6

Answer 12

Identify upper layer protocol

Question 13

Action(open flow)

Answer 13

Drop, forward, modify, send to controller

Question 14

eBGP

Answer 14

Obtain subnet reach ability from neighboring ASs

Question 15

iBGP

Answer 15

Propagate reachability info to all AS-internal routers. Allow subnet to advertise its existence to internet

Question 16

BGP session

Answer 16

Routers trade messages over semi-permanent TCP connection. Advertising paths to different destination network prefixes.

Question 17

AS-PATH

Answer 17

List of ASes thru which prefix advertisement has passed. Router ignore advertisement with itself in AS-PATH.

Question 18

NEXT-HOP

Answer 18

Indicates specific internal-AS router to next hop.

Question 19

Hot potato routing

Answer 19

BGP. Closest NEXT-HOP router.

Question 20

Network Control Apps

Answer 20

Brains of control: implement control function.

• API provides by SDN controller.
• Unbundled: can be provided by 3rd party or SDN controller.

Question 21

SDN Controller

Answer 21

Maintains network state information.

• interacts with network control apps “above” via northbound API.
• Interacts with network switches “below”

Question 22

Data plane switches

Answer 22

Fast, commodity switches that implement generalized forwarding.

• openflow protocol for controller msgs.
• switch flow table computed, installed by controller.

Question 23

Interface later to network control apps

Answer 23

Network Graph, RESTful API, intent

Question 24

Network-wide state management layer

Answer 24

State of networks switches, links, and services. (Statistics, flow tables, link-state info, host info, and switch info)

Question 25

Communication layer (SDN)

Answer 25

Communicate between SDN controller and controlled switches (openflow and SNMP)

Question 26

Open flow features

Answer 26

Controller queries switch features, switch replies

Question 27

Open flow configure

Answer 27

Controller queries/sets switch configuration parameters

Question 28

Open flow modify-state

Answer 28

Add, delete, modify flow entries in tables

Question 29

Open flow packet out

Answer 29

Controller can send this (infected) packet out of specific switch port

Question 30

ICMP type 11 code 0

Answer 30

TTL expired

Question 31

ICMP type 3 code 3

Answer 31

Dest port unreachable

Question 32

Nodal processing delay

Answer 32

Check bit errors, determine output link

Question 33

Transmission delay

Answer 33

Packet length/ link bandwidth

Question 34

Queuing delay

Answer 34

Waiting for output link for transmission

Question 35

TLD

Answer 35

.org, .com, .uk

Question 36

CNAME

Answer 36

DNS alias

Question 37

MX

Answer 37

DNS mail

Question 38

Type=NS

Answer 38

Includes host name of authoritative name server

Question 39

Enter Deep

Answer 39

Push CDN into many access networks, close to users

Question 40

Bring Home

Answer 40

Smaller number of large clusters in POPs bear access networks

Question 41

Pipelining

Answer 41

Sending multiple “in-flight” not yet acked packers