Marking Scheme

Assignments

Assignment 1

Only Questions 1, 5 and 6 were marked.

Q1: 5 marks, one per correct answer

Q5: 1 mark for -44dBm

Q6: marks:

• (a) 1 for 2.56 Mb/s and 320kB/s
• (b) 1 for 32 errors per burst
• (c) 1 for 32 rows
• (d) 1 for 64 bytes/codeword

 Assignment 2

Marked out of 5.  Marks were assigned as follows:

Q2: 1 mark for downstream

Q6: 1 mark for 31.25~kHz subcarrier spacing

Q7: 1 mark for 8-way

Q8: 1 mark for GSM first and LTE last

Q11: 1 mark for about 12.5s or 4/minute

 Assignment 3

Marked out of 8. Marks were assigned as follows:

Q1: 1 mark for byte-oriented framing

Q4: 1 mark for traffic intensity of 20 calls; 1 mark for about 27 trunks

Q7: 1 mark for first 4 bytes (0x45, 0x00, 0x00, 0x60)
       1 mark for correct last 4 bytes (0xc0, 0xa8, 0x00, 0x01)

Q9: 1 mark for yes

Q10: 1 mark for H having a route to 10.0.0.0/8 through interface 10.0.0.2;
        1 mark for H having a default route through 192.168.12.254 on interface 192.168.0.2

Assignment 4

Marked out of 8. Marks were assigned as follows:

Q1: 1 for costs=1 to 65536, 1 for range of data rates=100M to ~1500

Q2: 1 for any wikipedia address in 208.80.152/22 (or 192...), 1 for wikipedia ASN=14907

Q4: 1 for parsing into 4 TLV options, 1 for decoding the MTU option value=1540

Q5: 1 for server... A 142.232... record, 1 for not... MX 10 smtp... record

Assignment 5

Marked out of 8 as follows:

Q2: 1 mark for correct header: 14 3B 00 35 00 24 00 00 (length can also be 0x2c)

Q3: 1 mark for expect ACK bit to be set in response to a frame with FIN bit set

Q4: 1 mark for 105 (or 104) sent, 1 mark for 3235 received

Q5: 1 mark for adding correctly (10649), 1 mark for correctly computing checksum from that (F9B5)

Q6: 1 mark for network graph, 1 mark for showing routes between 1
    and 4 using interface to 3

Labs

Lab 1 Pre-Lab

Marked out of 2:

• 1 mark for anything that looks like a Matlab function
• 1 mark for computing quantization noise power 5e-6W or -23dBm

Lab 1 Report

Marked out of 5.  1 mark for each of the following:

• - ID
• - signal plots
• - summary table
• - discussion of results
• - including .wav file

Lab 2 Report

Marked out of 4.  1 mark for each of the following:

• - q1: sent over UDP
• - q4: DHCP discover differs from request in the Message Type Option field
• - q6: DHCP is encapsulated in broadcast IP packet
• - q12: a reasonable explanation of the purpose of lease time

Lab 3 Report

Marked out of 4.  1 mark for each of the following:

• - q4: uses UDP
• - q5: port is 53
• - q9: yes, TCP SYN sent to IP address of www.ietf.org (4.31.198.44) in DNS response
• - q19: screenshot of (nslookup or wireshark output for) response of NS for mit.edu

Lab 4 Report

Marked out of 4.  1 mark for each of the following:

• - identification
• - screen capture of topology
• - running config screen capture
• - ping screeen capture

Lab 5 Report

Marked out of 6.  1 mark for each of the following:

• - topology screen capture
• - show route outputs showing 'O' route for 3.0.0.0/8 via 1.0.0.2
• - show route outputs showing 'O' route for 3.0.0.0/8 via 2.0.0.3
• - traceroute output for at least one of these
• - wireshark capture of an OSPF Hello packet
• - wireshark capture of an OSPF LSA packet

Lab Completion

The lab completion mark is based on a report with reasonable complete set of results (waveforms, graphs, screen captures, etc).  No lab completion is awarded unless a report was produced.

Final Exam

Q1

•  computing spliter loss: 1
•  path loss = 18dB: 1
•  distance = 20km: 1

Q2

•  parsing into VPI/VCI values: 1
•  conver to decimal: 1
•  path: 1

Q3

•  flags: 1
•  header/trailer: 1
•  escaping escape character: 1

Q4

•  TTL=1: 1
•  destination IP address=A0,10,00,01: 1
•  ICMP response, protocol=1: 1

Q5

•  sets FIN to close: 1
•  gets ACK (plus maybe FIN) to acknoledge: 1

Q6

•  4 lines (OK, Content-Type, blank line, HTML): 1 mark per line

Q7

•  0.5 marks per correct answer