Assignment #1
DUE: Oct 20,2009.
Demo
will take place
in ENG 201 and ENG
202 on Tuesday Oct 20 from 11 - 12 AM
Marks: 15
Marks: 15
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The checksum is obtained by first taking the sum of the ASCII value of each data character in the block and dividing that sum by 255. Then the quotient is discarded and the remainder is appended to the block as the checksum. The receiving device performs the same operation and this "Internally" generated checksum is compared to the transmitted checksum. If the two checksums match, the block is considered to have been received error-free. You need to implement all aspects of the Data link layer. There should be Line control, Flow control, and error control. Format of the Frame First byte: Start of header (SOH- check ASCII table) Next byte: Block number or Sequence number Next byte: One's complement Obtained by subtracting block number from 255. Followed by 128 characters of data. Next byte: Checksum value Size of frame: 132 chars Error detection 1. If SOH is damaged send back a NAK. 2. If the block number or the one's complement is damaged, they will not be one's complement of each other. Send backs a NAK. 3. Checksum produced by the receiver does not match the transmitted value, transmit a NAK. * For all three situations the negative acknowledgement will serve as a request to the transmitting station to retransmit the previously transmitted block. You need to demonstrate error handling in the following situations: 1. Damaged Frame 2. Lost Ack 3. Lost NAK. Error checking to be demonstrated by use of signals (ie ^C – Damaged Frame ^Z – Lost ACK ^\ - Lost NAK) You need to have a "layer" that sits on top of this layer. The job of this layer is "End-to-End" transmission. At the sender's end: read a line of text from a file. At the reciver's end: discard duplicates,reorder frames and write to a file. Simulate the physical layer by the use of "pipes". Marking Scheme [ return to top of page ]  Assignment #2DUE: Nov 26,2009 from 10-12 am in ENG 201
Marks:
15 Consider the following network. In the table below, IP addresses for the serial interfaces and the ethernet interfaces are given. For the purposes of this assignment, you can ignore the ISDN link and the ethernet connections. Run RIP on all the routers. The routers should communicate with each other and broadcast all the connected links and thereby “learn” all reachable destinations. After the “steady state” is reached, you should be able to ping every router in the pod. For demonstrating your network in the lab, send a packet from PnR1 to PnR3. It should simulate the “traceroute” command.   Marking Schme:Static Routes: 6 marks; Process
communication:6 marks
Documentation: 3 marks
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