Term
| Identify the 7 layers of the OSI model |
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Definition
Layer 1) Physical
Layer 2) Data
Layer 3) Network
Layer 4) Transport
Layer 5) Session
Layer 6) Presentation
Layer 7) Application |
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Term
| What is the function of the first layer in the OSI model? |
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Definition
They Physical Layer defines the method of moving data between computers.
Anything that moves data from one system to another, such as copper cabling, fiber optics, radio waves, is part of layer 1
hubs are also in this layer |
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Term
| What is the function of the second layer in the OSI model? |
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Definition
The NIC's OSI Data Link Layer (Layer 2):
1) adds around each packet a frame that contains the MAC addresses for the sender/receiver's systems.
2) As the NIC assembles each fram, it checks the network to see if the cable is busy. If not, it sends the frame down the wire using to the "physcial" layer.
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Term
| What is the funciton of the third layer in the OSI model? |
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Definition
The OSI Network layer software adds to each packet the MAC addresses of the receiver and sender, and then send the packets to the second layer (Data Link).
The last layer that deals directly with hardware. All the other layers work strictly within software.
The IP protocal is the primary protocal that TCP/IP uses at Layer 3 of the OSI model. |
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Term
| What is the function of the fourth layer in the OSI model? |
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Definition
| The OSI Transport layer software chops the data into packets and assigns each a sequence number, so that the receiver's computer will know how to reassemble the packets when they arrive. |
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Term
| What is the function of the fifth layer in the OSI model? |
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Definition
| The OSI Session layer establishes a connection between two computers, accepts incoming sessions, and opens and closes existing sessions. |
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Term
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Definition
Protocols are a set of instructions that define rules, regulations, standards, and procedures so that hardware and software developers can make devices and applictions that function properly.
Each protocol is designed to deal with a specific layer.
Each protocol must be able to understand the previous and preceding protocols before it, but oblivious to the others. |
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Term
| What is a "Network Protocol?" |
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Definition
Network Protocals (such as TCP and IP) create unique identifiers for each system, and create communication rules for how to handle data packets.
Network Protocols move beyond the physical MAC addresses, and start using logical addressing with specific software (aka, "network protocols") |
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Term
| Where does a hub send data? |
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Definition
| To all of the systems connected to the hub |
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Term
| What uniquely identifies every NIC? |
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Definition
| Media Access Control address (MAC address) |
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Term
| What Windows utility do you use to find the MAC address for a system? |
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Definition
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Term
| The MAC address is known as a ________ address? |
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Definition
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Term
| A NIC sends data in discrete chunks called_____? |
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Definition
Frames.
Data is sent in discrete chunks called frames. Networks use frames to keep any one NIC from hogging the wire.
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Term
| Which MAC address begins a frame? |
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Definition
The Receiving system.
The frame begins with the MAC address of the receiving NIC, followed by the MAC address of the sending NIC, followed in turn by the data and CRC. |
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Term
| A frame ends with a special bit called the cyclic redundancy check (CRC). What does the CRC do? |
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Definition
Verifies that the data arrived correctly.
The data is followed by a special bit of checking info called the CRC, which the receiving NIC uses to verify that the data arrived correctly. |
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Term
Which of the following is an example of a MAC address?
A) 0-255
B)00-50-56-A3-04-0C
C) SBY3M7
D) 192.168.4.13 |
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Definition
B)00-50-56-A3-04-0C
A MAC address is a 48-bit value, and no two NICs ever share the same MAC address. |
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Term
| Which layer of the OSI sevel-layer model controls the assembly and disassembly of data? |
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Definition
The Transport Layer.
The transport layer controlls the assembly and disassembly of data |
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