Collision detection, Computer Network Security

COLLISION DETECTION

The signals from two devices will interfere with each other and the overlapping of frames is known a collision. It does not cause to the hardware but data from each frames is grabbled.

ETHERNET CD:

 To check the collision, Ethernet interfaces add hardware to detect transmission. It acts two operations:

  • It monitors sender signals.
  • Grabbled signal is interpreted as a collision.

After collision is detected computers stop transferring. So Ethernet needs CSMA/CD to coordinate transmission.

 

RECOVERY FROM COLLISION:

 Computer that find a collision sends special signal to force all other interfaces to find collision.

 Computer then waits for other to be idle before transfer. But if both devices wait for same length of time, packet frames will collide again. So the standard specifies largest delay and both devices select random delay, which is lesser. After waiting, devices use carrier sense to avoid subsequence collision. The device with shorter delay will go first and other computer may transfer later.

EXPONENTIAL BACK OFF:

 Even with random delays, collision may happen especially likely with busy code segments. Computers double delay with every subsequent collision. It replace likely hood of sequence of collision.

 

 

Posted Date: 7/30/2012 7:24:36 AM | Location : United States







Related Discussions:- Collision detection, Assignment Help, Ask Question on Collision detection, Get Answer, Expert's Help, Collision detection Discussions

Write discussion on Collision detection
Your posts are moderated
Related Questions
Dynamic Packet Filtering Dynamic Packet Filtering is also referred to as stateful firewalling. Here the firewall maintains the status of connections as well. When a connection

Evaluations, Assessment, and Maintenance of Risk Controls When the control strategy has been implemented, it should be monitored and measured on an ongoing basis to determine ef

Question: (a) Give 2 benefits of using IPsec. (b) IPSec uses two protocol for security: Authentication Header protocol (AH) and the Encapsulated Security Header Protocol (


Question 1 a) What is a NMS? Question 2 Explain about Structure of Management Information Question 3 A)In which UDP port number does a protocol entity receive message?

Question (a) For the bit stream 010011, show the waveforms for each of the code indicated. Consider that the signal level for NRZ-L for mark is positive; the signal level for t

Host-Based IDS A host-based IDS (HIDS) resides on a particular computer or server and monitors activity only on that system. HIDS also called as system integrity verifiers as th

Digital Certificates Digital Certificates are electronic document having key value and identifying information about entity which controls key. Digital signature which is attach

Let me know the details of protocol tcp/ip

QUESTION: (a) Below is a capture of an Ethernet II frame which contains an IPv4 packet and a TCP segment. Give the source MAC address for the frame in hexadecimal; the sourc