Test Case

COURSE CODE 3050402 PG DIPLOMA EXAMINATION - JAN 2009 PGDCA
COMPUTER conversation AND NETWORK Time: 3 Hours Max.Marks:75 Section - A
9. expand ICMP?
Internet aver Message Protocol (ICMP) defined by RFC 792 and RFC 1122 is used for communicate error reporting and generating messages that require attention. The errors describe by ICMP argon generally related to datagram processing. ICMP only reports errors involving dismantle 0 of any fragmented datagrams. The IP, UDP or TCP form will usually take action found on ICMP messages. ICMP generally belongs to the IP layer of TCP/IP merely relies on IP for support at the profit layer. ICMP messages are encapsulated inside IP datagrams.
ICMP will report the following network information:
Timeouts
Network over-crowding
Network errors such as an unaccessible host or network.
The ping command is also back up by ICMP, and this can be used to debug network problems.


19. a. Explain about congestion control?
Congestion Control http://cnx.org/content/m13361/latest/
A technique for observe network utilization and manipulating transmission or forwarding grade for data frames to keep traffic levels from overwhelming the network medium. It gets its key out because it avoids network traffic jams.



[6]
In Asynchronous Transfer trend ( aura) networks, congestion control schemes may be based on fields at heart the ATM cell header (CLP, EFCI within the PTI) or may be based on a more sophisticated mechanism between the ATM end-system and ATM switches. The ATM Forum has developed a mechanism based on rate control for Available Bit respect (ABR)-type traffic. In Frame Relay networks, congestion is handled by the FECN, BECN and DE bits.

What causes congestion?

The assumption that statistical multiplexing can be used to mitigate the link utilization is that the users do not reach their point in time rate values simultaneously, but since the traffic demands are stochastic and cannot be predicted, congestion is unavoidable....If you want to get a enough essay, order it on our website: Orderessay



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