What are the OSI Layers from top to bottom?
Application, Presentation, Session, Transport, Network, Data link and Physical
What are the TCP/IP Layers?
Application, Transport, Internet and Network Access
What happens at the application layer? (OSI)
The software interacts with the network and the OS
What happens at the Presentation layer?
Translation: Networks can connect very different types of computers together: PCs, Macintoshes, UNIX systems, AS/400 servers and mainframes can all exist on the same network. These systems have many distinct characteristics and represent data in different
What happens at the Session layer?
Maintain communication. "Handshake
What happens at the Transport layer?
Error correction, application separation (ports).
What are the 2 main transport protocols?
TCP, UDP
TCP is unreliable
False. TCP asks for acknowledgement after a packet is sent to its destination (confirms that the packet was delivered).
UDP is Unreliable
True. UDP does not ask for confirmation after a package is delivered. This is mostly used for real-time communication such as VoIP or Live communication.
What happens at the Network layer?
Find the best possible route the get to its destination (end to end). Logical addressing. It never changes.
Logical Addressing: Every device that communicates over a network has associated with it a logical address, sometimes called a layer three address.
What happens at the Data Link layer?
Find the local area network the packet is been sent to. Physical address. Changes as it goes from network to network.
Data Link Layer Sublayers: Logical Link Control (LLC) and Media Access Control (MAC)
The data link layer is often conceptually divided in
What happens at the Physical layer?
Passes the bits (01s) using electric or optical signals.
Definition of Hardware Specifications: The details of operation of cables, connectors, wireless radio transceivers, network interface cards and other hardware devices are generally a function of the
What happens at the Application layer (TCP/IP)
The software interacts with the network or OS, encryption, reformatting, and starts communication.
What happens at the Internet layer?
The data is packed into IP diagrams which contains the source and destination logical addresses.
What happens at the Network Access layer?
Defines how the data is physically sent through the network using hardware devices such as coaxial cables, fiber optic, switches and more.
Application layer protocols
HTTP, HTTPS, FTP, SSH, SMTP, DHCP, NFS, Telnet, SNMP, POP3, NNTP and IRC
Some common Presentation layer formats are
Graphics files JPEG, TIFF, GIF, and so on are graphics file formats that require the data to be formatted in a certain way.
Text and data The presentation layer can translate data into different formats such as American Standard Code for Information Inter
Some common network protocols are:
ARP, SPX/IPX, Apple Talk, IP (IPv4, IPv6), ICMP, IGMP, RIP, EGP
Some common Data Link layer protocols are:
PPP (Point-to-Point Protocol) and SLIP (Serial Line Internet Protocol).
FTP Ports
20, 21
SHH Ports
22
Telnet ports
23
SMTP ports
25
DNS ports
53
DHCP ports
67,68
TFTP ports
69
HTTP ports
80
HTTPS ports
443
SSL VPN ports
443
POP3 ports
110
NTP ports
123
IMAP4 ports
143
SNMP ports
161
IPsec ports
500
RDP
3389
1 byte is _ bits
8
1 kilobyte is _ bytes
1024
1 Megabyte is _ kilobytes
1024
1 gigabytes is _ megabytes
1024
If you have a video of 100MB and you are using a router with a data transfer speed of 900Mbps with a network card that supports it, how long it would take to transfer the data?
.88 seconds
Belong to layer 2. Allow devices to interconnect.
Switch
Belong to layer 3. Separate networks and contains traffic
Router
Allow wireless conections
WAP (Wireless Access Points)
Whats the maximum length of a cat5 cable which guarantees no signal loss?
100 meters
Ethernet cables are____ ____ that sends ____ signals
twisted pair, electrical
Fiber optic cables are ___ ____ which sends _ signals
glass tubes, light
What is the wireless standard?
802.11
What are the wireless standard expansions?
a, ac, b, g, n
What is the speed, frequency, rage and, MIMO streams for 802.11a?
54, 5, 20, 1
What is the speed, frequency, rage and, MIMO streams for 802.11ac?
433/channel, 5, 35, 8
What is the speed, frequency, rage and, MIMO streams for 802.11b?
11, 2.4, 100, 1
What is the speed, frequency, rage and, MIMO streams for 802.11g?
54, 2.4, 100, 1
What is the speed, frequency, rage and, MIMO streams for 802.11n?
150, 2.4 or 5, 70, 4
What happens when a person that is connected on your 802.11b/g/n wireless router has a b network card and all your other computers are connected using an b/g/n capable network card?
A router does not provide separate standards according to the network card the user has. Therefore, the router switches to 802.11b on all network connections to allow all computers to connect.