CTS Networking Flashcards
Define a network
Two or more nodes interconnected so they can share data.
Networks have two main parts:
Nodes (any device that sends and receives data) and connections (physical means data travels from one mode to another).
Is a patch panel a node or a connection?
Connection!
Is a switch a node or a connection?
Node!
PAN?
Personal Area Network. Limited range wireless network that serves a single person or small workgroup.
CAN?
Campus area network. Communications network covers a group of adjacent buildings within the same organisation.
MAN?
Metropolitan area network. Network that covers a suburb or a city.
GAN?
Global area network. Network that spans the globe. The internet!
What are two ways you can categorise networks and which is better?
Geographically (PAN, CAN, MAN, GAN…) or whether nodes use physical or logical addresses to communicate. Second is better.
What does MAC address stand for?
Media Access Control Address
Do LANs use physical or logical address to communicate?
Physical. Uses the MAC address.
Describe a LAN (characteristics, not logistics).
privately owned and operated. Fast and high capacity. Required devices to be directly and physically connected.
Name 6 different kinds of LAN topology.
bus, ring, star, meshed, partially meshed, extended star.
Describe LAN bus topology.
All nodes connected through a single cable. Any node fails everything beyond it goes down.
Describe LAN ring topology.
Nodes are arranged in sequence like bus, but makes a circle. Info can go both directions, which makes redundant paths. If one node fails info still flows.
Describe LAN star topology.
All nodes connect to a single point (router, switch, hub). If one node fails info still flows. Central device is a single point of failure.
Describe LAN meshed topology.
Each node connects to every other node. Fast and redundant. Expense to create that many physical connections, though. Rare.
Describe LAN partially meshed topology.
Nodes connect to several other nodes, but not all. Good redundancy - several must fail at once to stop communication.
Describe LAN extended star topology.
A star with several layers of hierarchy. Device fails and everything below is cut off but the rest of the network works. Central device is still a single point of failure.
What is a WAN?
A network that connects one or more LANs together. WANs use logical address to communicate.
What is a logical address?
Usually an IP address (Internet Protocol).
What type of network uses a logical address?
WAN
What are the nodes on a WAN?
Routers. The router is at the top of the LAN network hierarchy.
What does the router do before sending info from the LAN to the WAN?
Strips the packet of identifying LAN information, like MAC addresses. This protects devices on the LAN.
Why can’t many networked AV protocols travel over WANs?
WANs are slower than LAN because they travel farther. Those extra fractions of a second add up and cause problems.
What do you call a private WAN?
An enterprise network. Secure government entities are likely to use these.
What are the two definitions of an enterprise network?
- Communication backbone of a large network. Every note connects to the core backbone.
- Any large, geographically dispersed private network.
Describe WAN hub and spoke topology.
Each LAN connects to a central location (branches connecting to corporate headquarters). Can have several layers of hierarchy like a star LAN.
Describe WAN common carrier topology.
Each LAN runs to an Internet service provider (ISP) backbone.
Describe WAN meshed topology.
Every LAN connects to every other LAN. Excellent redundancy.
What WAN and LAN topologies look like each other?
Star and Hub and Spoke.
Define Gateway
Connects a private network to outside networks. They translate data from one protocol to another.
Define Router
Routers forward data between devices that are not physically connected. In the Network Layer. Routers mark the border of the WAN and LAN.
Define unmanaged switch
Provides a physical connection between multiple devices. Switches collect and store MAC addresses for each connected device. Operate on the Data Link layer. No configuration options.
Define managed switch
Physical connection between multiple devices. Collects and stores MAC addresses. Data Link layer. Allows adjusting port speeds, setting up VLANs, etc. More common than unmanaged.
What does every device that connects to the network must have?
A NIC (network interface card) and associated MAC address. Some devices may have more than one NIC, esp if they have to connect to multiple networks. Each NIC will have it’s own MAC address.
MAC addresses are part of what standard?
IEEE 803
A MAC address is how many bits and looks like what?
48-bit consisting of 6 groups of hexadecimal numbers separated by hyphen or colon.
What do the parts of a MAC address mean?
First part tells the manufacturer, second is serial number.
Is Ethernet connection baseband or broadband?
Baseband (uses entire frequency range of the cable to send data)
What does a switch do if it gets an Ethernet frame addressed to an unfamiliar MAC address?
Sends it out to everything on the network except the node it arrived on. If the device it was intended for gets the info the switch will receive an acknowledgement that the packet arrived and will update it’s lookup table.
What’s the difference between a switch and a hub?
A hub broadcasts frames to all ports, including the one on which it received the frame.
What is Ethernet?
A family of computer networking technologies for LANs
Data over Ethernet separates streams of data into shorter pieces called what?
Frames.
What does each frame contain?
Source and destination addresses, and error checking data.
What is full duplex (in regards to Ethernet)?
Means the switch and station can communicate with each other simultaneously. This makes Ethernet completely collision free.
What’s the difference between a frame and a packet?
Frames happen in the Network Access Layer (data link, physical). Packets happen on the Internet layer, or Network layer.
Describe a hub.
Half-duplex. Can send and receive data, but not both at the same time. All devices have to share the network’s bandwidth. Slow down networks a lot and aren’t used anymore much.
What is a server?
Not a piece of hardware – a role a piece of hardware can play. Almost any hardware can be used as a server. Provides services to dependent nodes.
Two definitions of what a server can be:
- ) A server is a piece of hardware that does nothing but provide services.
- ) A server can also be a program that runs on a computer with other programs.
How are servers usually named?
After the service they provide.
Why would a server need to be it’s own device?
- ) It needs the CPU power and storage capacity.
2. ) It’s mission critical and needs a separately maintained device.
What’s a thin server?
A server that offers only one service. Can be on dedicated hardware or a virtualized instance configured with only functionality needed to provide the service.
Name the parts of the electromagnetic spectrum in order of increasing frequency and/or increasing wavelength.
Radio and TV, Microwave, Infrared, Visible light, Ultraviolet, X-ray, Gammaray.
Name 3 different ways of transmitting electromagnetic energy.
- Copper (as voltage)
- Glass (as visible light)
- Air (as radio frequencies)
What’s the benefit of twisting wires in a cable run?
Makes sure each wire is subjected to the same outside interference. This lets the resulting noise be canceled out in the input circuit. Protection from electromagnetic interference at low frequencies.
Name and describe 2 kinds of twisted pair cable.
- ) UTP (unshielded twisted pair). Lighter weight, more flexible, lower cost.
- ) STP (shielded twisted pair). Gives greater bandwidth (?) and longer cable runs.
What are the “Cats” in Ethernet?
Categories of twisted pair cable under EIA/TIA 568 Ethernet standards.
What CATs are currently unrecognized by TIA/EIA?
CAT 1 - CAT 5
What twisted pair cable is used for telephone and doorbell type connections?
CAT 1
What twisted pair cable has speed up to 100 MHz (typically 100 Mbps)?
CAT 5
What twisted pair cable has speeds up to 20 MHz (typically 16 Mbps)
CAT 4
What twisted pair cable has speeds up to 250 MHz (typically both 100 Mbps and 1 Gps)
CAT 5e (defined in TIA/EIA-568-B)
What twisted pair cable has speeds up to 500 MHz (typically both 100 Mbps and 1 Gps)
CAT 6 (defined in TIA/EIA-568-B)
What’s the speed of CAT 6a cable?
up to 500 MHz - typically 10 Gbps (defined in TIA/EIA-568-B.2-10)
What’s the speed of CAT 7 cable?
up to 600 MHz - typically 10 Gbps (Informal - ISO/IEC 11801 Class F cabling)
What twisted pair cable is 100-ohm unshielded and associated with connecting hardware specified for data transmission up to 100 Mbps?
CAT 5