Operation of IP Networks Flashcards
Mnemonic for OSI Model (from TOP-to-BOTTOM)
All People Seem To Need Data Processing
Define Layer 1 functions and DoD model equivalent
1) Sending and Receiving Bits
2) Converting data bits into Electrical Pulses, Radio Waves, or Pulses of Light
3) Defining the Mechanical, Electrical, Procedural, and Functional specifications for Activating, Maintaining, and Deactivating the physical link between systems
Equivalent to the Network Access DoD Layer.
Mnemonic for OSI Model (from BOTTOM-to-TOP)
Please Do Not Throw Sausage Pizza Away
Define Layer 2 functions and DoD Model equivalent
1) Logical Link Control(LLC) sublayer is responsible for:
- Error Recovery of data through Retransmitting
- using Sequencing for maintaining orderly delivery of frames
- Flow Control of data (Windowing, Acknowledgements, Buffering)
2) Media Access Control (MAC) sublayer is responsible for:
- Physical Addressing for data transmission
- Error Checking by adding Cyclical Redundancy Check (CRC)
- identifying Network topologies and devices
Equivalent to the Network Access DoD Layer.
Define Layer 3 functions and DoD Model equivalent
1) Logical Addressing
2) Path Determination (identification and selection)
3) Routing Packets
4) Maintaining a list of known Networks and Addresses of Routers
Equivalent to Internet DoD Layer.
Define Layer 4 functions and DoD Model equivalent
1) Reliable or Unreliable data transport
2) End-to-end Flow Control
3) Segmenting, Sequencing, and Combination
4) Using Port(or Socket) Numbers for identifying distinct applications running on the same system
Equivalent to the Host-to-host DoD Layer.
Define Layer 5 functions and DoD Model equivalent
1) Keeping Data Streams separate from each other.
2) Establishing, Maintaining, and Tearing down sessions.
3) 3 modes used to coordinate and organize communication between applications at the Session layer: Simplex, Half-Duplex, and Full-Duplex modes.
Equivalent to the Application/Process DoD Layer.
Define Layer 6 functions and DoD Model equivalent
1) Translating and Formatting data
2) Encrypting, Decrypting, Compressing, and Decompressing
Equivalent to the Application/Process DoD Layer.
Define Layer 7 functions and DoD Model equivalent
1) Providing an interface for the user to communicate with the computer directly
2) Enabling Network Services on the OS
3) Determining the availability of communication partners, and the required resources for communication
Equivalent to the Application/Process DoD Layer
Define the OSI Model.
A Reference Model that organizes and defines the steps that data takes to travel across the network from one system to another.
Router
1) Layer 3 Device
2) Breaks up Broadcast Domains
3) Packet Selection and Routing
Switch
1) Layer 2 Device
2) Breaks ups Collision Domains
3) Can intelligently forward data to only destination address
4) Filters, Floods, and Forwards Frames
Bridge
1) Layer 2 Device
2) Connects media segments that use the same protocols
3) Filters or Forwards traffic based on destination address
4) Software based
5) Breaks of Collision Domains but creates one Broadcast Domain
Hub
1) Layer 1 Device
2) Repeats received data out all ports except the port it received it on
3) Creates one collision domain and one broadcast domain
Upper OSI Model Layers
Defines how end stations communicate with each other and the user.
Lower OSI Model Layers
Defines how data is transmitted end-to-end.
Flow Control
“ready” and “not ready” signals
- A way for the receiving device to control the amount of data sent by the sender.
Windowing
“Increase/decrease window size”
Used to control the amount of Unacknowledged data segments are sent.
Auto-Detect Mechanism
Used in Ethernet switch, hub, and interface cards to determine
the duplex and speed that can be used.
Half-Duplex
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Full-Duplex
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Number of bits/bytes in MAC Address?
48-bits (6 bytes)
First 24-bits of MAC Address
OUI - Organizationally Unique Identifier
Second 24-bits of MAC Address
Vendor Assigned
Nibble
4 bits or half a byte
Byte
8 bits
Field in Ethernet Frame: Preamble
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Field in Ethernet Frame: Start Frame Delimiter (SFD)/Synch
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Field in Ethernet Frame: Destination Address (DA)
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Field in Ethernet Frame: Source Address (SA)
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Field in Ethernet Frame: TYPE/LENGTH
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Field in Ethernet Frame: Frame Check Sequence (FCS)
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Crosstalk
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Straight-through Cable
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Crossover Cable
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Rolled Cable
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CSMA/CD
Used in half-duplex networks to detect collisions and allow hosts so share the same cable but only one can transmit at a time
OSI stands for?
Open Systems Interconnection
ISO stands for?
International Organization for Standardization
Things that can cause LAN traffic congestion:
1) Low bandwidth
2) Broadcast storms
3) Too many hosts in a collision/broadcast domain
4) Too much multicast traffic
5) Bunches of ARP broadcasts
6) Adding hubs for connectivity to the network
Internetwork
Two or more networks connected via a router and a configured logical addressing scheme (e.g. IP, IPv6)
These network devices operate on all 7 layers of the OSI Model:
- Network management stations (NMSs)
- Web & application servers
- Gateways (Not default gateways)
- Servers
- Network hosts
If any of these 4 are in a connection, the connection will be considered connection-oriented.
- Virtual Circuit/”three-way-handshake”
- Sequencing
- Acknowledgements
- Flow Control
