Go Back   Computer Forums > General Computing > Networking | DNS
Join Computer forums Today

Thread Tools Search this Thread Display Modes
Old 10-02-2005, 07:52 PM   #1
Beta Member
Join Date: Oct 2005
Posts: 2
Default Networks questions....!!!!

dear all,

can you please explain these questions below in networking....

your help is really appreciated...

best regards,

To configure a new computer to be attached to the Internet without using autocon- figuration services such as DHCP, you need to specify four parameters in order to make the Internet- working part work properly. Name these parameters, and for each parameter describe why it is important.

Assuming that an attack would succeed in bringing down all of the root servers in the DNS system, what implications would that have to the operation and usability of the Internet?

Multiple Access

a) Protocols like ALOHA and CSMA/CD are also called statistical multiplexing protocols.

Why? What are the advantages as compared to TDMA, FDMA, and CDMA?

b) Suppose nodes A and B are on the same 10Mbit/s Ethernet segment (CDMA/CD).

Node A begins transmitting a frame and, before it finishes and before the frame reaches B, also node B begins transmitting a frame. What is the condition that both A and B

can detect the collision? Assuming that the propagation delay between the two nodes is 225 bit times (1 bit time = 1 bit / 10Mbit/s), what is the minimum frame size allowing collision detection?


In this problem you will derive the efficiency of a CSMA/CD-like multiple access protocol. In this protocol, time is slotted and all adapters are synchronised to the slots. Unlike slotted ALOHA, however, the length of a slot (in time) is much less than a frame time (the time to transmit a frame). Let T be the length of a slot. Suppose all frames are of constant length L = kRT, where R is the transmission rate of the channel and k is an integer. Suppose there are N nodes,each with an infinite number of frames to send. We also assume that P (propagation time) is smaller than T, so that all nodes can detect a collision before the end of a slot time. The protocol is as follows:

If, for a given slot, no node has possession of the channel, all nodes contend for the channel; in particular, each node tranmits in the slot with probability p. If exactly one node transmits in the slot, that node takes possession of the channel for the subsequent k − 1 slots and transmits its entire frame.

If some node has possession of the channel, all other nodes refrain from transmitting until the node that possesses the channel has finished transmitting its frame. Once this node has transmitted its frame, all nodes contend for the channel.

Note that the channel alternates between two states: the productive state, which lasts exactly k slots, and the nonproductive state, which lasts for a random number of slots. Clearly, the channel efficiency is the ratio of k/(k+x), where x is the expected number of consecutive unproductive slots.

(a) For fixed N and p, determine the efficiency of this protocol.

(b) For fixed N, determine the p that maximises the efficiency.

(c) Using the p (which is a function of N) found in (b), determine the efficiency as N approaches infinity.

(d) Show that this efficiency appraoches 1 as the frame length becomes large.

heroine is offline   Reply With Quote
Old 10-03-2005, 01:39 PM   #2
Baseband Member
jhowell's Avatar
Join Date: Aug 2005
Posts: 38

Copied that straight from your textbook eh.

jhowell is offline   Reply With Quote
Old 10-04-2005, 05:13 AM   #3
Beta Member
Join Date: Oct 2005
Posts: 2

do you have the answers?
plzzzzzzzzzzzzzzzzzzz help...
i am seriously in need to find the solutions to those questions mentioned above.....
plzzzz help
thanks for reading,,,
heroine is offline   Reply With Quote
Old 10-04-2005, 02:06 PM   #4
In Runtime
Interlaced's Avatar
Join Date: Jan 2005
Posts: 163
Default Re: Networks questions....!!!!

DHCP Parameters:
IP address
Subnet Mask
Default Gateway
DNS server

DNS Question:
You would not be able to access any websites by typing their domain names it would only be accesible via the ip addresses of the specific web server.
Lets all get naked and send pics :)
Interlaced is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

All times are GMT -5. The time now is 06:33 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.6.0