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What is a PAN?
Personal Area Network
What is a SAN?
Storage Area Network
What is a VLAN?
Virtual LAN
Implemented on switches
Provide:




  • Scalability

  • Segmentation

  • Limited Security (Layer 2)

  • Limit size of broadcasts


What is a WLAN?
Wireless LAN
What is a CAN?
Campus Area Network
What is a MAN?
Metropolitan Area Network
Name the 7 Layers of the OSI Model
OSI Model Mnemonic
The short form used to memorize the layer names of the OSI Model is “All People Seem TNeed Data Processing
Physical Layer
Layer 1

Specifies the electrical, mechanical and functional requirements of the network, including the topology, cabling, connectors and interface types.   Also the process for converting bits to electrical signals.
Name the 4 basic network topologies
  • Star
  • Mesh
  • Ring
  • Bus
Name the 4 basic types of cable used in networks
  • Coaxial
  • Twinaxial
  • Twisted-Pair
  • Fiber-optic
Name the two types of Coaxial cable and their connector types
  • Thick (RG8 or RG11, AUI)
  • Thin (RG58, BNC)
Describe the 7 twisted-pair cable catagories
TIA/EIA Category
ISO Class
Use & Speed
Example
1
Voice only
Telephone
2
Data (up to 4Mbps)
Token Ring
3
Data (up to 10Mbps)
Ethernet
4
Up to 20Mbps
Token Ring
5
Up to 100Mbps
Fast Ethernet
5e
D
Up to 1000Mbps @ 100MHz
Gigabit Ethernet
6
E
Up to 1000Mbps @ 250MHz
Gigabit Ethernet
6a
Ea
Up to 10Gbps
10 Gb Ethernet
7
F
Up to 10Gbps @600MHz @100m
10 Gb Ethernet
7a
Fa
Up to 10Gbps @1000MHz @15m
40 Gb Ethernet

Cat (Class) Speed Example



  • 1 Voice only Telephone

  • 2 to 4Mbps Token Ring

  • 3 to 10Mbps Ethernet

  • 4 to 20Mbps Token Ring

  • 5 to 100Mbps Fast Ethernet

  • 5e (D) Gb Ethernet

  • 6 (E) Gb Ethernet

  • 6a (Ea) 10 Gb Ethernet

  • 7 (F) 10 Gb Ethernet

  • 7a (Fa) 40 Gb Ethernet


What is the difference between a network hub and a switch?
A hub sends packets to all devices on the network where a switch sends packets only to destination devices.

Data Link Layer
Layer 2

Ensures devices are delivered to the proper device (switchboard)



Two sub-layers:

Logical Link Control (LLC)

Media Access Control (MAC)
Logical Link Layer (LLC)
Sub-layer of the Data Link Layer
Functions:
  • Manages the control, sequencing and acknowledgement of frames
  • Responsible for timing and flow control
Media Access Layer (MAC)
Responsible for framing and:



  • Error control (CRC)

  • Addressing (MAC address)

  • Controls media access


CSMA/CD
Token 
Polling
Name several common LAN (layer 2) protocols
  • ARCnet
  • Ethernet
  • Token-Ring
  • FDDI
  • ARP
  • RARP
What is RARP?
Reverse Address Resolution Protocol.  It is the opposite of ARP.  It maps MAC addresses to IP Addresses.
What is ARP?
It is a layer 2 protocol that maps IP Addresses to MAC addresses
Name the 3 types of LAN data transmissions.
  • Unicast
  • Multicast
  • Broadcast
List and describe the 4 IEEE Wireless LAN standards
802.11a 54Mbps 5GHz
802.11b 11Mbps 2.4GHz (first)
802.11g 54Mbps 2.4GHz
802.11n 600Mbps 5GHz or 2.4GHz
List several point-to-point protocols
L2F - Layer 2 Forwarding
L2TP - Layer 2 Tunneling Protocol
PPP - Point-to-point protocol
PPTP - Point-to-point tunneling protocol
SLIP - Serial line IP
Describe common-circuit switched networks

Circuit-switched networks are ideal for always on connections.
  • DSL - Digital Line Subscriber
  • ISDN - Integrated Services Digital Network
What are packet-switched networks?
Devices share bandwidth.  Ideal for on-demand networks with bursts of traffic.
List types of WAN protocols used in packet-switched networks
  • ATM
  • Frame Relay
  • MPLS
  • SONET
  • SDH
  • SMDS
  • X.25
What is ATM?
Asynchronous transfer mode.
High-speed, low delay
Used in fiber-optics
What is Frame Relay?
HDLC encapsulation.
Used on switched virtual circuits (SVC) or Permanent Virtual Circuits (PVC).
What is MPLS?
Multi-Protocol Label Switching
High speed
Scalable
Versatile
Used in fully meshed VPN's
Layer 2 & 3.
Label Edge Routers (LER)
Label Switch Routers (LSR)
Disadvantage: customer loses visibility into the cloud
What is SONET?
Synchronous Optical Network
SDH - Synchronous digital heirarchy
High availabiliy
High speed
Mux'd
used on fiber.
What is SMDS?
Switched Multimegabit Data Service
What is a datagram?
Routable unit of data, similar to an IP packet.  Used in UDP and Appletalk.
What is HDLC?
High-Level Data Link Control.
data encapsulation method
default for serial links on Cisco routers
What is SDLC?
Synchronous Data Link Control.
IBM
Polling
primary and secondaries.
List common telecommunications circuits.
DS0 Digital signal Level 0
DS1 1.544Mbps
DS3 44.7Mbps
T1 1.544Mbps
T3 44.7Mbps
E1 Europe
E3 Europe
OC-1 SONET
OC-3 SONET
OC-12 SONET
OC-48 SONET
OC-192 SONET
What is the difference between asynchronous and synchronous communications?
Asynch devices must communicate at the same speed, determined by slower device.  No clocking. Parity bits used for error detection.

Synch devices use internal clock.  Large blocks of data.  High speed.
Layer 2 Networking Devices
  • Bridge
  • Switch
  • DTE
What is a Bridge?
  • Semi-intelligent repeater
  • connects two or more network segments
  • Maintains an ARP cache
  • Forwards (non-local) messages to all other network segments
  • Common problem of bridges is broadcast storms
What is a Switch?
  • Intelligent hub
  • Uses MAC addresses to route traffic
  • Transmits data only to port with the destination address
  • Can be used to implement VLANs
  • Traditionally Layer 2 devices
Data Terminal Equipment (DTE)
Devices at the user end of a user-to-network interface
What is the Network Layer responsible for?
Routing
Name 3 Routing Protocols and 2 Routed Protocols
Routing:
  • RIP
  • OSPF
  • BGP

Routed:
  • IP
  • IPX
What is a Class A IP Address?
Addresses up to 126.xxx.xxx.xxx.   They are for large networks (>16million hosts).
What is a Class B IP Address?
Addresses between 128.xxx.xxx.xxx and 191.xxx.xxx.xxx.  They are for medium networks (>65k hosts)
What is a Class C IP Address?
Addresses between 192.xxx.xxx.xxx and 223.xxx.xxx.xxx.  For small networks (254 hosts).
What is a Class D IP Address?
Addresses between 224.xxx.xxx.xxx and 239.xxx.xxx.xxx.  Used for Multicast.
What is a Class E IP Address?
Addresses between 240.xxx.xxx.xxx and 254.xxx.xxx.xxx.   Used for experimental purposes.
What is IP address range 127.xxx.xxx.xxx reserved for?
Loopback and testing.
Name the range of reserved addresses in Class A
10.xxx.xxx.xxx
Name the range of reserved addresses in Class B
172.016.0.0 to 172.032.0.0
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