Chapter 4 BB Flashcards
When trying to communicate with someone on the same LAN, is an IP address sufficient? Pg 94
No, a MAC address is needed
If someone you’re trying to send something to is on the same LAN as you, how do you retrieve their MAC address if you do not know it? Pg 94-95
broadcast a message requesting their MAC address, identifying them using their IP address.
What is Ethernet and what is one reason it’s so popular? Pg 95
Ethernet is a contention media-access method that allows all hosts on a network to share the same bandwidth of a link. Ethernet is readily scalable which contributes to its popularity.
What is collision domain? Pg 95
When a device on an ethernet connection sends a packet out on a network segment thereby forcing every other device on the same physical network segment to pay attention to it.
What is a collision event and what environment is it typically found in? Pg 95-96
An event that occurs when two devices on the same physical segment transmit at the same time causing their signals to interfere with one another and forcing them both to re-transmit at a later time. This greatly slows the network down and is typical in a hub environment wherein the hub represents only one collision domain and one broadcast domain.
What is a broadcast domain? Pg 96
The set of all devices on a network segment that hear all broadcasts on that segment. Can also reference a logical division of a network segment where all gosts can reach each other via a Data Link Layer broadcast.
What is the purpose of CSMA/CD? Pg 96
Carrier Sense Multiple Access with Collision Detection is a media access control method that keeps two devices from transmitting at the same time on the network in order to help devices share the bandwidth evenly.
Which devices can prevent a transmission from propagating throughout the entire network? Pg 96
bridges, switches, and routers
In CSMA/CD, what will a transmitting host do if they detect another begin to transmit a signal after they have already begun transmitting? Pg 96
Send out an extended jam signal that the other hosts respond to by holding their transmissions until the wire is free.
How many time will a host attempt to retransmit before timing out? Pg 96
15 times.
What 4 things happen when a collision occurs on an Ethernet LAN? Pg 97
- A jam signal informs all devices a collision occurred
- the collision invokes a random backoff algorithm
- Each device stops transmitting until the timers expire
- All hosts have equal priority to transmit after the timers have expired
What are the effects of having a CSMA/CD network sustain heavy collisions? Pg 97
- Delay
- Low Throughput
- Congestion
What is broadband? Pg 98
Can send multiple frequencies of different signals down the same wire at the same time (called frequency-division multiplexing), and can send both analog and digital signals.
What is baseband? Pg 98
What LANs use, all the bandwidth of the physical media is used by only one signal.
Why is bps used as a measurement over baud rate? Pg 98
Baud rate is one electronic state change per second, but one state change can involve more than one bit, thus bits per second is a more accurate measurement of computing speed.
