2.2 Compare and contrast common networking hardware devices Flashcards
What is a NIC?
Network Interface Card
- Fundamental network device.
- Every device on the network has a NIC
Ethernet network = Ethernet NIC
What is a Repeater?
Extends a network
- Receives a signal, regenerates it, and then resends that signal out another interface
- Repeater only repeats it out a single interface
No forwarding decisions to make
Common use:
- Boosts copper or fiber connections
- Convert one network media to another
- Extend wireless network reach
What is a Hub?
(Old technology. Not used. Replaced by Switches)
Also knows as a Multi-port Repeater
- Traffic going in one port is repeated to every other port (i.e. Information sent to one interface on this hub is automatically repeated to every other interface)
- With a hub you’re repeating the signal out of multiple interfaces simultaneously
- Becomes less efficient as network speeds increase
- Half Duplex (this means 2 devices cant communicate at the same time on a hub)
Only operates at 10 megabits / 100 megabits per second. You won’t find any gigabit hubs.
What is a Bridge?
(Old technology. Not used. Replaced by Switches)
Basically a switch with two to four ports
- Makes forwarding decisions in software
- Distributes traffic based on MAC addresses
- Connects different physical networks (connects different topologies) e.x. We can move from an ethernet network (LAN) to a WAN by sending that traffic through a bridge
(A modern Bridge is a Wireless Access Point - It bridges wired Ethernet to wireless). That router is performing a Bridging function.
What is a Switch?
Bridging done in hardware
A Switch works on the MAC address (every network card has a MAC address that is unique to that card)
- The switching hardware is: Application-specific integrated circuit (ASIC)
- Forwards traffic based on data link address
- Many ports and features
- Full Duplex = Sends and receives data at same time
Looks at the destination MAC address and sends that information to the appropriate interface on the switch.
-Multilayer Switch - Includes routing functionality “Layer 3 Switch”
Unmanaged Switch
Very few configuration options
PnP
Fixed configuration
Managed Switch
VLAN support
Traffic Prioritization
Redundancy Support
Network management station can communicate to these devices using a specialized protocol called SNMP (Simple Network Management Protocol)
What are Routers?
Routes IP addresses between IP subnets
- Makes forwarding decisions based on IP address
- Connects diverse network types (LAN, WAN, copper, fiber) (Different topologies)
What are Wireless Access Points? (WAP)
“literally just a WiFi radio that provides a hotspot for your wireless devices to connect to.”
-They are not a router
- WAP is a bridge
- It extends the wired network onto the wireless network
- Makes forwarding decisions based on MAC address
Wireless LAN controller
Centralized management of WAPs
- Deploy new access points
- Performance and security monitoring
- Configure and deploy changes to all sites
- Report on access point usage
Firewalls
Filters traffic by port number
*OSI Layer 4 (TCP/UDP)
Can encrypt traffic into/out of the network
Can proxy traffic - Means they sit it in the middle of the communication
Most firewalls can be layer 3 devices (routers)
Cable Modems
Uses the same wire we traditionally use for our Televisions
DOCSIS (Data Over Cable Service Interface Specification)
- Cabling that carries TV signals
- Coaxial Cabling
- Shared Bandwidth
Different types of throughput is supported
- 4 Mbit/s through 250 Mbit/s are common
- Gigabit speeds are possible
Multiple services can be utilized
-Already supporting video through the network, so we can include DATA and VOICE
DSL Modem
Uses the same wire we traditionally use for our telephones
ADSL (Asymmetric Digital Subscriber Line)
It’s asymmetric because the download speed is faster than the upload speed
One challenge: Significant distance limitation betwen telephone company’s central office and telephone jack that’s in your home
- Max distance 10,000 ft.
- 52 Mbit/s downstream and 15 Mbit/s upstream
- Closer to the central office = faster speeds
What are Midspans?
What are Endspans?
Midspans are in-line power injectors. They provide PoE to a device that a switch can’t.
Endspans are switches that have built in power and provide that power to the device.
