Chapter 4 Flashcards
What are the four processes the Network layer uses to provide end-to-end access?
- Addressing
- Encapsulation
- Routing
- Decapsulation
What is the purpose of the Network layer?
The network layer packages L4 segments and add a logical address. It passes packets with minimal overhead and divides networks into groups to manage data flow.
There are three charastics to IPv4 and IPv6 protocols, what are they?
- Connectionless
- Best Effort
- Media Independant
What is ‘Connectionless’ transmissions?
No connection is made before the data is sent to assure the receiving end is online.
What is ‘Best Effort’ transmission?
IP does not guarantee that all packets will be received.
What is ‘Media Independent’ transmission?
IP Packets are unaware of the media used to transmit packets.
What four items compose an IPv4 Packet?
- The Source and Destination IP
- Time to Live (TTL)
- Differentiated services
- Protocol
Describe the TTL in an IPv4 packet.
An 8-bit long indication to the “Lifespan” of a packet. At each hop, the TTL goes down by one.
What are the three most common IPv4 Protocols?
01: ICMP
06: TCP
17: UDP
What is Differentiated services in an IPv4 packet?
Quality of Service (QoS)
What is Bandwidth
The Theoretical Maximum Speed for transmitting information.
What is Throughput
The actual speed of transmitting information.
What is Goodput
The speed of all successful network transmissions.
What is the primary difference between Synchronous and Asynchronous signaling?
Sync. sends packets in order on a set timing schedule, while Async. sends packets all at once with no timing.
What is EMI?
Electromagnetic interference: signals that can distort and/or corrupt the data sent over copper media.
What is RFI?
Radio frequency interference: signals that can distort and/or corrupt the data sent over copper media.
What is Crosstalk?
Crosstalk is a disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an adjacent wire.
What are the three types of copper media?
UTP, STP, and Coax.
What is the largest Pro of using Fiber over Copper?
Fiber is faster and is completely immune to EMI, RFI, and Crosstalk.
What is the largest Con of using Fiber over Copper?
Fiber is much more expensive and harder to terminate.
What is the difference between Single Mode and Multimode Fiber?
Single Mode allows for only a single path for light to travel. Multimode allows for multiple paths for light to travel.
What type of copper cable would you use to connect a Computer to a Switch?
Straight-through.
What type of copper cable would you use to connect a Computer to a Router?
Crossover.
What type of cable would you use to connect a PC to a Cisco Router or Switches Console Port?
Rollover.
What is the difference between CSMA/CD and CSMA/CA?
CD is Collision Detection, while CS is Collision Avoidance.
What is CSMA/CD?
Collision detection works by checking the media for a data signal. If there is a signal on the line the device has to wait and try again later. If a collision occurs, the two senders back off and receive a random amount of time to time-out.
What is CSMA/CA?
With Collision Avoidance, the device checks the media for a signal and sends a notification of its intent to use it. After the notification, the device then sends the data.
What device will prevent Collision and never rarely needs to use CSMA/CD?
Switches.
What is CSMA?
Carrier Sense Multiple Access was first used to detect if the media is carrying a signal. If two devices transmit at the same time; data collision occurs.
