Net. 1: Ch 4 Network Access (TCPIP Layer) Flashcards

1
Q

node

A

Layer 2 notation for a network device connected to a common media.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2 Basic Services of Data Link Layer

A
  1. Accept Layer 3 data packets and packs them into frames.

2. Controls media access control and performs error detection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

2 Sublayers of Data Link Layer

A
  1. Logical Link Control

2. Media Access Control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Logical Link Control

A

LLC: defines the software processes that provide services to the network protocols- identifies which network layer protocol is being used in the frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Media Access Control

A

MAC: defines the media access processes performed by the hardware - provides data link layer addressing and delimiting of data.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Actions of Router Along Path

A
  1. Accepts frame from a medium.
  2. De-encapsulates the frame.
  3. Re-encapsulates the packet into a new frame.
  4. Forwards new frame appropriate to the medium of that segment of the physical network.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

3 Parts of a Frame

A
  1. Header
  2. Data
  3. Trailer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Header

A

Part of a frame that contains control information , addressing, ahead of the PDU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Data

A

contains IP header, transport layer header, and application data.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Trailer

A

contains control information for error detection; after PDU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Parts of Header

A
  1. Start Flag: marks start of frame : used by MAC sublayer.
  2. Addressing: used by MAC sublayer to identify source and destination nodes.
  3. Type: used by LLC to identify the layer 3 protocol.
  4. Control: id’s flow control/other control services.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Parts of Trailer

A
  1. Error Detection: CRC check for errors

2. Stop Flag: marks end of frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Definers of Open L2 standards

A
  1. Institute of Electrical and Electronics Engineers.
  2. xx
  3. International Telecommunications Union (ITU)
    ADSL, ISDN
  4. International Organization for Standardization
    (ISO) High Level Data Link Control
  5. American National Standards Institute (ANSI)
    Fiber Distributed Data Interface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

WAN Physical Topologies

A
  1. Point to Point
  2. Hub and Spoke: WAN star.
  3. Mesh
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

virtual circuit

A

logical connection between two network devices within a network

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

half-duplex

A

communication mode where you can send or receive at the same time.

17
Q

full-duplex

A

communication mode where you can send and receive at the same time.

18
Q

Physical Lan Topologies

A
  1. Bus
  2. Star
  3. Ring
  4. Extended Star/Hybrid
19
Q

2 MAC Methods for Shared Media

A
  1. Contention Based Access

2. Controlled Based Access

20
Q

Contention Based Access

A

All nodes compete for medium use but have plan if collisions occur.

21
Q

Controlled Based Access

A

Each node has how time to use the medium.

22
Q

Carrier Sense Multiple Access

A

CSMA: Method used in contention based networks to detect if another node is transmitting data.

23
Q

CSMA/CD

A

Carrier Sense Multiple Access/Collision Detection

Data is sent when medium is free, if collisions are detected all nodes stop Tx and resend later.

24
Q

CSMA/CA

A

Carrier Sense Multiple Access/Collision Avoidance
Checks for signal on medium; if free sends an intent to Tx signal over network; waits for confirmation to send then sends data.

25
Q

multi-access topology

A

One node at a time sends , but sends to all other nodes; only recipient node uses data.

26
Q

Controlled Access Topology

A
  • network devices take turns to send data
  • uses token; only token holder can Tx
  • aka “scheduled access” or “deterministic”
27
Q

Possible Control Fields in Header/Control

A
  1. Priority/Quality of Service
  2. Logical connection control.
  3. Physical Link Control: used to establish media link.
  4. Flow Control Field
  5. Congestion Control Field: indicates congestion
28
Q

Data Link Addressing

A
  • referred to as physical address (MAC)
  • contained in frame header
  • device specific
29
Q

Frame Check Sequence

A

FCS: part of trailer used in cyclic redundancy check(CRC): carries value that is used to check to see if any errors in data has occured.

30
Q

3 Common Data Link LAN Protocols

A
  1. Ethernet 802.2/802.3: CSMA/CD
  2. Point to Point Protocol
  3. 802.11 Wireless.
31
Q

Ethernet Frame Composition.

A
  1. Preamble - used for synchronization
  2. Destination Address: 48 bit MAC
  3. Source Address: 48 bit MAC
  4. Type: indicates which upper level protocol receives frame after Ethernet processes.
  5. DataL Data PDU
  6. Frame Check Sequence
32
Q

Point to Point Frame Composition

A
  1. Flag: signals begin or end of frame: 01111110
  2. Addresses: PPP broadcast station.
  3. Control: calls for transmission of data in unsequenced frame: 00000011
  4. Protocol: identifies protocol encapsulated in data field.
  5. Data contains datagram
  6. Frame Check Sequence: 16 or 32 bits.
33
Q

Wireless LAN Frame

A
  1. Frame Control: includes many sublayers
  2. Duration /ID: time in microseconds to transmit frame or Association ID (AID) of transmitting station.
  3. Destination Address (AD): MAC
  4. Source Address (SD): MAC
  5. Receiver Address (RA): MAC of wireless device that is immediate recipient of frame.
  6. Sequence Control
  7. Tramsitter Address(TA): MAC of wireless device that transmitted the frame.
  8. Frame Body
  9. Frame Check Sequence: 32 bit crc value.