Preliminary Design

 

Requested by:                 Mr. Ken Swarner

                                      Systems Administrator

                                      Computer Science Department of Siena College

 

 

 

 

 

 

 

 

TCP/IP Packet Descriptor

 

 

Mirage Incorporated

“We are there…even if you cannot see us”

Mirageinc2003@yahoo.com

 

 

 

 

 

Prepared by:                   Paul Aiuto

                                      Richard Connell

                                      Lauren Englisbe, Team Leader

                                      Jayme Gresen

                                      Jeffrey Habiniak

 

 

 

December 5, 2003

 

Preliminary Design

Table of Contents

 

1.0 External Design Specifications

 

3

     1.1 User Displays

 

3-12

     1.2 User Command Summary

 

13

     1.3 Detailed Data Flow Diagrams

 

14-16

     1.4 Hardware, Software, and Human Interfaces

 

17

2.0 Architectural Design Specification

 

18

     2.1 User Commands (AKA “Clickable Buttons”)

 

18

     2.2 Functional Descriptions

 

19

       2.2.1 IP PDU for the selected FTP PDU

 

19-32

       2.2.2 TCP PDU for the selected FTP PDU

 

33-43

       2.2.3 FTP PDU for the selected FTP PDU

 

44

       2.2.4 IP PDU for the selected ICMP PDU

 

45-57

       2.2.5 ICMP PDU for the selected ICMP PDU

 

58-64

3.0 Appendix

 

65              

     3.1 Glossary

 

65-67

     3.2 Gantt Chart

 

68-69

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.0 External Design Specifications

           

1.1  User displays

 

 

            This will be the first screen the user sees.  It is the introduction screen to our software, and presents our mascot, “The Descript-roar”.

 

 

 

 

 

 

 

This is the first functional screen the user will see.  It allows the user to see what an Ethernet Packet looks like, and eventually each frame within that packet will be clickable and able to display information about that frame.

 

            The “Choose a Protocol” menu gives the user a graphical representation of how protocols are interrelated, and allows the desired protocol to be selected.

 

 

 

 

 

            Once a protocol has been selected by the user, this screen will display.  The basis for our protocol suite, the IP PDU is displayed on the left, filled in with the given data for the selected protocol.  The user is able to click on any field in the IP PDU, and an information box will display on the right, describing that field.  In the IP PDU Data field, “TCP PDU” is written – this indicates that the entire TCP PDU is contained within the IP Data field.  If the user clicks on this field, the TCP PDU will be displayed.

 

The PDUs are tabbed on their lower left corners: this allows the user to navigate between them.  Additionally, there is a key at the top right corner to display what PDUs make up the chosen protocol.  The user may also click on any PDU in this map to navigate.  If at any point, the user wants to choose a different protocol to view, he or she may click on the “Choose a Protocol” button in the top left corner.

 

 

 

 

The next screen shows the TCP PDU on top of the IP PDU.  This is meant to show that the TCP PDU is contained within the IP PDU.  Additionally, the FTP PDU is contained within the TCP PDU Data field, so clicking on that field will display the FTP PDU.  As with IP, if a TCP field is clicked, the information for that field will be displayed in the information box at the right.

 

 

 

 

 

This is the software with all the information displayed for the selected FTP PDU.  The IP PDU gives rise to the TCP PDU, and the TCP Data field has been clicked, which allows us to see the information field for the FTP PDU on the right.

 

 

 

 

Mirage has provided a number of prototype options, which will be chosen by the client at a later date.

 

Prototype Model Option 1 (IP PDU):

 

 

 

Prototype Model Option 2 (TCP PDU):

 

 

 

 

We also have two choices to allow for information display for a given field.

 

Information Field Option 1:

 

 

 

Information Field Option 2:

 

 

 

 

This is the user display using our second option for the Information Field:

 

 

1.2 User Command Summary

Main Screen

This is the screen giving the user the option to choose many different packets.

PDU Hierarchy Tree

Allows the user to see their progression through the many packets, and also able to choose their desired packet.

 

IP Version

Allows the user two chooses of two different IP Versions.

 

Radix (Base) Selection

Allows the user to select a radix to display.

 

Information Box

Allows the user to see the given information for a selected field.

1.3 Detailed Data Flow Diagrams

 

Level 0 Diagram:

 

Context Diagram:

 

Detailed Diagram:

 

 

 

 

1.4 Hardware, Software and Human Interfaces

 

The prototype was developed and designed on Macromedia Fireworks, a graphic design program. 

 

The program will be written in HTML using Macromedia MX and perhaps PHP (PHP Hypertext Processor) Version 4.1.2.

 

The TCP/IP Packet Descriptor program will be hosted as a web site on the Siena College Computer Science Department’s Oraserv Linux server (Red Hat version 7.1), running the Apache web server (version 1.3.19).

 

Any Netscape Navigator 7.x or greater and Internet Explorer 5.x or greater web browser may access the program.

 

 

2.0 Architectural Design Specification

 

2.1 User Commands (AKA “Clickable Buttons”)

 

IP PDU

 

IP Version

Internet Header Length

Type of Service

Total Length of Ethernet Frame

Identification

Flags

Fragment Offset

Time to Live

Protocol

Header Checksum

Source IP Address

Destination IP Address

Options

Data

 

TCP PDU

 

Source Port Number

Destination Port Number

Sequence Number

Acknowledgement Number

Header Lengths

Reserved

Window Size

TCP Checksum

Urgent Pointer

Options

Data

2.2 Functional Descriptions

 

2.2.1 IP PDU for the selected FTP PDU

 

IP PDU > IP Version for the selected FTP PDU

 

Field Name: IP Version

 

Purpose and Definition:  Version is a 4-bit field that indicates the format of the internet header.

 

Field Key:       4 = IPv4

            6 = IPv6

 

Data value (decimal):  4

 

Data values in other bases:

 

Hexadecimal

4

Binary

0100

Decimal

4

 

Programming Hint: The name for this variable in code will be IP_IPVersion_FTP.

IP PDU > Internet Header Length for the selected FTP PDU

 

Field Name:  Internet Header Length

 

Purpose and Definition:  The IHL field is a 4-bit field indicating the length of the internet header in 32 bit words, and thus points to the beginning of the data.  The minimum value of a correct header is 5.

 

Field Key:  Not applicable

 

Data value:  The value contained in our field is 20 bytes.  This is the hexadecimal and decimal value of 5 multiplied by 4 bits.

 

Data values in other bases:

 

Hexadecimal

0

5

Binary

0000

0101

Decimal

5

 

Programming Hint: The name for this variable in code will be IP_IHL_FTP.

IP PDU > Type of Service for the selected FTP PDU

 

Field Name:  Type of Service

 

Purpose and Definition:  Type of Service is an 8-bit field that provides and indication of the abstract parameters of the quality of service desired.  These parameters guide the selection of the actual service parameters when transmitting a datagram through a particular network.

 

Field Key:  The major choice is a three-way tradeoff between low-delay, high-reliability, and high-throughput.

 

 

 

 


Bits 0-2: Precedence

Bit 3: (D)  0 = Normal Delay                1 = Low Delay

Bit 4: (T)  0 = Normal Throughput        1 = High Throughput

Bit 5: (R)  0 = Normal Reliability           1 = High Reliability

 

Precedence:

            111 = Network Control                        011 = Flash

            110 = Internetwork Control                  010 = Immediate

            101 = CRITIC/ECP                             001 = Priority

            100 = Flash Overrided             000 = Routine

 

Data value (hexadecimal): 10

 

Data values in other bases:

 

Hexadecimal

1

0

Binary

0001

0000

Decimal

16

 

Programming Hint: The name for this variable in code will be IP_TypeOfService_FTP.

IP PDU > Total Length of Ethernet Frame for the selected FTP PDU

 

Field Name: Total Length of Ethernet Frame

 

Purpose and Definition: Total Length is a 16-bit field that indicates the length of the frame, measured in octets, including internet header and data.  The maximum size is 216-1 or 65,535 octets; however, the recommended maximum size is 576 octets.

 

Field Key:  Not applicable

 

Data values (hexadecimal):  69

 

Data values in other bases:

 

Hexadecimal

0

0

6

9

Binary

0000

0000

0110

1001

Decimal

0

105

ASCII

©

i

 

Programming Hint: The name for this variable in code will be IP_TotalLength_FTP.

IP PDU > Identification for the selected FTP PDU

 

Field Name:  Identification

 

Purpose and Definition:  Identification is a 16-bit field.  An identifying value is assigned by the sender to aid in assembling the fragments of a datagram.  The identifier is chosen based on the need to provide a way to uniquely identify the fragments and protocol for the time the datagram or any fragment could be alive in the internet.

 

Field Key:  Not applicable

 

Data value (hexadecimal): AA 41

 

Data values in other bases:

 

Hexadecimal

A

A

4

1

Binary

1010

1010

0100

0001

 

Programming Hint: The name for this variable in code will be IP_Idenfification_FTP.

IP PDU > Flags for the selected FTP PDU

 

Field Name:  Flags

 

Purpose and Definition:  Flags is a 3-bit field that indicates directions for fragmentation.

 

Field Key:

Bit 0: reserved, must be 0

Bit 1: (DF)  0 = May Fragment             1 = Don’t Fragment

Bit 2: (MF) 0 = Last Fragment              1 = More Fragment

 

Data value (binary): 010

 

Data values in other bases:  Not applicable

 

Programming Hint: The name for this variable in code will be IP_Flags_FTP.

 

IP PDU > Fragment Offset for the selected FTP PDU

 

Field Name:  Fragment Offset

 

Purpose and Definition:  The Fragment Offset is a 13- bit field indicating where in the Ethernet frame this fragment begins.  The Fragment Offset is measured in units of 8 octets, and the first fragment has offset 0.

 

Field Key:  Not applicable

 

Data value (decimal): 0

 

Data values in other bases:

Binary: 0 0000 0000 0000

 

Programming Hint: The name for this variable in code will be IP_FragmentOffset_FTP.

IP PDU > Time to Live for the selected FTP PDU

 

Field Name: Time to Live

 

Purpose and Definition:  Time to Live is an 8-bit field that indicates the maximum time the datagram is allowed to remain in the internet.  If this field contains the value 0, then the datagram must be destroyed.  This field is modified in internet header processing.  The time is measure in units of seconds, and is set by the sender to the maximum time the datagram is allowed to be in the internet.  This field is decreased at each point that the internet header is processed.  The intention is to cause undeliverable packets to be discarded, and to bind the maximum datagram lifetime.

 

Field Key:  Not applicable

 

Data value (decimal): 64

 

Data values in other bases:

 

Hexadecimal

4

0

Binary

0100

0000

Decimal

64

 

Programming Hint: The name for this variable in code will be IP_TimeToLive_FTP.

IP PDU > Protocol for the selected FTP PDU

 

Field Name:  Protocol

 

Purpose and Definition:  Protocol is an 8-bit field that indicates the next level protocol that is used in the data portion of the internet diagram.

 

Field Key:

Dec Hex         Protocol                                                          Dec                 Hex       Protocol

0            00      Reserved                                                          22                    16          Multiplexing

1            01      ICMP                                                              23                    17          DCN

2            02      Unassigned                                                       24                    18           TAC Monitoring       

3            03      Gateway-to-Gateway                                       25-76               19-4C     Unassigned               

4            04      CMCC Gateway Monitoring Message  77                    4D          Any local network

5            05      ST                                                                    100                  64          SATNET and Backroom EXPAK

6            06      TCP                                                                 101                  65          MIT Subnet Support

7            07      UCL                                                                102-104           66-68     Unassigned

10          0A     Unassigned                                                       105                  69           SATNET Monitoring

11          0B      Secure                                                              106                  6A         Unassigned

12          0C     BBN RCC Monitoring                          107                  6B          Internet Packet Core Utility

13          0D     NVP                                                                110-113           6E-71    Unassigned

14          0E      PUP                                                                 114                  72           Backroom SATNET Monitoring

15          0F      Pluribus                                                            115                  73           Unassigned

16        10       Telnet                                                               116                  74           WIDEBAND Monitoring

17        11       XNET                                                              117                  75          WIDEBAND EXPAK

20        14       Chaos                                                              120-376           78-0178  Unassigned

21        15       User Datagram                                     377                  0179        Reserved

 

Data value (hexadecimal): 06

 

Data values in other bases:

 

Hexadecimal

0

6

Binary

0000

0110

Decimal

6

 

RFC Link: http://www.faqs.org/rfcs/rfc790.html

 

Programming Hint: The name for this variable in code will be IP_Protocol_FTP.

IP PDU > Header Checksum for the selected FTP PDU

 

Field Name:  Header Checksum

 

Purpose and Definition:  The Header Checksum is a 16-bit field.  The Checksum is the 16-bit one’s complement sum of all 16-bit words in the header.  For purposes of computing the checksum, the initial value of its field is zero.  When both header checksums are equal, then the header bits are correct.  If either checksums vary, then a new, correct packet will need to be sent.

 

This is a simple way to compute the checksum and experimental evidence indicates that it is adequate, but it is provisional and may be replaced by a CRC procedure, depending on further experience.

 

Field Key:  Not applicable

 

Data value (hexadecimal): 0E 85

 

Data values in other bases:

 

Hexadecimal

0

E

8

5

Binary

0000

1110

1000

0101

 

Programming Hint: The name for this variable in code will be IP_HeaderChecksum_FTP.

IP PDU > Source Address for the selected FTP PDU

 

Field Name:  Source Address

 

Purpose and Definition:  The Source Address is a 32-bit field that contains the IP address of the host that sent the IP Packet.

 

Field Key:  Not applicable

 

Data value (decimal):  192.168.0.39

 

Data values in other bases:

 

Hexadecimal

C

0

A

8

0

0

2

7

Binary

1100

0000

1010

1000

0000

0000

0010

0111

Decimal

192

168

0

39

 

Programming Hint: The name for this variable in code will be IP_SourceAddress_FTP.

IP PDU > Destination Address for the selected FTP PDU

 

Field Name:  Destination Address

 

Purpose and Definition:  The Destination Address is a 32-bit field that contains the address of the host that is to receive the data contained within the IP packet.

 

Field Key: Not applicable

 

Data value (decimal):  192.168.0.101

 

Data values in other bases:

 

Hexadecimal

C

0

A

8

0

0

6

5

Binary

1100

0000

1010

1000

0000

0000

0110

0101

Decimal

192

168

0

101

 

Programming Hint: The name for this variable in code will be IP_DestinationAddress_FTP.

IP PDU > Options and Padding for the selected FTP PDU

 

Field Name:  Options and Padding

 

Purpose and Definition:  The options may or may not appear in Ethernet packets.  They must be implemented by all IP modules (host and gateways).  What is optional is their transmission in any particular packet, not their implementation.

 

The option field is variable in length.  There may be zero or more options.  There are two cases for the format of an option.

            Case 1: A single octet of option type

            Case 2: An option-type octet, an option-length octet, and the actual option-data                                    octets.

 

Field Key:  Not applicable

 

Data values:  Not applicable

 

Data values in other bases:  Not applicable

 

Programming Hint: The name for this variable in code will be IP_OptionsPadding_FTP.

 

IP PDU > Data for the selected FTP PDU

 

Field Name:  Data

 

Purpose and Definition:  The Data is a variable length field which contains the actual data that is being sent from one host to another.  The data field may start with a Layer 4 header, which will give additional instructions to the application that will be receiving the data; alternately, it may be an ICMP header and not contain any user data at all.

 

Field Key:  Not applicable

 

Data values (hexadecimal) :  (TCP) 80 30 00 15 81 A5 16 6C 87 A3 53 5D 80 18 16 D0 11 F4 00 00 01 01 08 0A 1B 25 F3 A1 0b DD 73 58

(FTP) 50 41 53 53 20 66 31 61 32 6B 33 75 73 65 72 0D 0A

 

Data values in other bases:

Hexadecimal: (TCP) 0 x 80 30 00 15 81 A5 16 6C 87 A3 53 5D 80 18 16 D0 11 F4 00 00 01 01 08 0A 1B 25 F3 A1 0B DD 73 58

(FTP) 50 41 53 53 20 66 31 61 32 6B 33 75 73 65 72 0D 0A

 

ASCII:  (TCP) ↑ 0 © © ↑ ↑ © ↑ ↑ S ] ↑ © © ↑ © ↑ © © © © © © © % ↑ ↑ © ↑ s X

(FTP) P A S S S © f 1 a 2 k 3 u s e r © ©

 

Programming Hint: The name for this variable in code will be IP_Data_FTP.

 

 

2.2.2 TCP PDU for the selected FTP PDU

 

IP > TCP PDU > Source Port for the selected FTP PDU

 

Field Name:  Source Port

 

Purpose and Definition:

This 16-bit number represents the name of the application that sent the data in the IP packet.

 

Field Key:  Not applicable

 

Data value (decimal): 32816

 

Data values in other bases:

 

Hexadecimal

8

0

3

0

Binary

1000

0000

0011

0000

Decimal

128

48

ASCII

á

0

 

Programming Hint: The name for this variable in code will be IP_TCP_SourcePort_FTP.

IP > TCP PDU > Destination Port for the selected FTP PDU

 

Field Name: Destination Port

 

Purpose and Definition:
This 16-bit number represents the name of the application that is to receive the data contained within the IP packet. This is one of the major differences between a Layer 3 and a Layer 4 header: the Layer 3 header contains the IP address of the computer that is to receive the IP packet; once that packet has been received, the port address in the Layer 4 header ensures that the data contained within that IP packet is passed to the correct application on that computer.

 

Field Key:

This key indicates assigned port number values:

Dec                       Port Numbers

0                                            Reserved
1-32767                 Internet registered ("well-known") protocols
32768-98303         Reserved, to allow TCPv7-TCPv4 conversion
98304 & up            Dynamic assignment

 

Data value (decimal): 21 (indicates FTP)

 

Data values in other bases:

 

Hexadecimal

0

0

1

5

Binary

0000

0000

0001

0101

Decimal

0

21

ASCII

©

©

 

Source: http://www.zvon.org/tmRFC/RFC1475/Output/chapter4.html

 

Programming Hint: The name for this variable in code will be IP_TCP_DestinationPort_FTP.

IP > TCP PDU > Sequence Number for the selected FTP PDU

 

Field Name:  Sequence Number

 

Purpose and Definition:
TCP is responsible for ensuring that all IP packets sent are actually received. When an application's data is packaged into IP packets, TCP will give each IP packet a sequence number. Once all the packets have arrived at the receiving computer, TCP uses the number in this 32-bit field to ensure that all of the packets actually arrived and are in the correct sequence.

 

Field Key:  Not applicable

 

Data value (decimal): 2175080044

 

Data values in other bases:

 

Hexadecimal

8

1

A

5

1

6

6

C

Binary

0000

0000

0011

1100

1010

1010

0011

1100

Decimal

0

60

176

60

ASCII

©

‘

á

‘

 

Programming Hint: The name for this variable in code will be IP_TCP_SequenceNumber_FTP.

IP > TCP PDU > Acknowledgement Number for the selected FTP PDU

 

Field Name: Acknowledgement Number

Purpose and Definition:
This number is used by the receiving computer to acknowledge which packets have successfully arrived. This number will be the sequence number of the next packet the receiver is ready to receive.

Field Key:  Not applicable

 

Data value: 2275627869

 

Data values in other bases:

 

Hexadecimal

8

7

A

3

5

3

5

D

Binary

1000

0111

1010

0011

0101

0011

0101

1101

Decimal

135

163

83

93

ASCII

á

á

S

]

 

Programming Hint: The name for this variable in code will be IP_TCP_AcknowledgementNumber_FTP.

IP > TCP PDU > Header Length or Offset for the selected FTP PDU

 

Field Name:  Header Length or Offset

 

Purpose and Definition:
This is identical in concept to the header length in an IP packet, except this time it indicates the length of the TCP header.

 

Field Key:  Not applicable

Data value (bytes): 32

Data values in other bases:

 

Hexadecimal

8

0

Binary

1000

0000

Decimal

128

ASCII

á

 

Programming Hint: The name for this variable in code will be IP_TCP_HeaderLength_FTP.

IP > TCP PDU > Reserved for the selected FTP PDU

 

Field Name:  Reserved

 

Purpose and Definition:
These 6 bits are unused and are always set to 0.

 

Field Key:  Not applicable

 

Data value (binary): 0000 00

 

Data values in other bases:

 

Hexadecimal

0

0

0

0

0

0

Binary

0000

0000

0000

0000

0000

0000

Decimal

0

0

0

ASCII

©

©

©

 

Programming Hint: The name for this variable in code will be IP_TCP_Reserved_FTP.

IP > TCP PDU > Control Flags for the selected FTP PDU

 

Field Name:  Control Flags

 

Purpose and Definition:
Every TCP packet contains this 6-bit value that indicates how many octets it can receive at once. When IP packets are received, they are placed in a temporary area of RAM known as a buffer until the receiving computer has a chance to process them; this value represents how big a buffer the receiving host has made available for this temporary storage of IP packets.

 

Field Key:

 

Data value (binary): 01 1000

 

Data values in other bases:  Not applicable

 

Programming Hint: The name for this variable in code will be IP_TCP_ControlFlags_FTP.

 

 

IP > TCP PDU > Window Size for the selected FTP PDU

 

Field Name:  Window Size

Purpose and Definition:
Every TCP packet contains this 16-bit value that indicates how many octets it can receive at once. When IP packets are received, they are placed in a temporary area of RAM known as a buffer until the receiving computer has a chance to process them; this value represents how big a buffer the receiving host has made available for this temporary storage of IP packets.

 

Field Key:  Not applicable

 

Data value (decimal): 5840

 

Data values in other bases:

 

Hexadecimal

1

6

D

0

Binary

0001

0110

1110

0000

Decimal

22

224

ASCII

©

á

 

Programming Hint: The name for this variable in code will be IP_TCP_WindowSize_FTP.

IP > TCP PDU > Checksum for the selected FTP PDU

 

Field Name:  Checksum

 

Purpose and Definition:
Unlike IP, TCP is responsible for ensuring that the entire IP packet arrived intact. TCP will run a CRC on the entire IP packet (not just the header) and place the resulting checksum in this field. When the IP packet is received, TCP re-runs the CRC on the entire packet to ensure the checksum is the same.

 

Field Key:  Not applicable

 

Data value (hexadecimal): 11 F4

 

Data values in other bases:

 

Hexadecimal

1

1

F

4

Binary

0001

0001

1111

0100

Decimal

17

244

ASCII

©

©

 

Programming Hint: The name for this variable in code will be IP_TCP_Checksum_FTP.

IP > TCP PDU > Urgent Pointer for the selected FTP PDU

Field Name: Urgent Pointer

Purpose and Definition:
If the Urgent flag is set to on, this value indicates where the urgent data is located.

Information Key:  Not applicable

 

Data value:  Not applicable

 

Data values in other bases:  Not applicable

 

Programming Hint: The name for this variable in code will be IP_TCP_UrgentPointer_FTP.

 

 

IP > TCP PDU > Options and Padding for the selected FTP PDU

 

Field Name: Options and Padding

 

Purpose and Definition:
Like IP options, this field is optional and represents additional instructions not covered in the other TCP fields. Again, if an option does not fill up a 32-bit word, it will be filled in with padding bits.

 

Field Key:  Not applicable

 

Data value (hexadecimal): 01 01 08 0A 1B 25 F3 A1 0B DD 73 58

 

Data values in other bases:

 

Hexadecimal

0

1

0

1

0

8

0

A

1

B

Binary

0000

0001

0000

0001

0000

1000

0000

1010

0001

1011

Decimal

1

1

8

10

27

ASCII

©

©

©

©

©

 

 

Hexadecimal

2

5

F

3

A

1

0

B

D

D

Binary

0010

0101

1111

0011

1010

0001

0000

1011

1101

1101

Decimal

37

243

161

11

221

ASCII

%

á

á

©

á

 

Hexadecimal

7

3

5

8

Binary

0101

0011

0101

1000

Decimal

115

96

ASCII

á

á

 

Programming Hint: The name for this variable in code will be IP_TCP_OptionsPadding_FTP.
2.2.3 FTP PDU for the selected FTP PDU

 

IP >TCP > FTP PDU for the FTP Packet

 

RFC Link:  http://www.ietf.org/rfc/rfc0959.txt?number=959

 

PASS (Password)

            The argument field is a Telnet string specifying the user’s password.  This command must be immediately preceded by the user name command, and, for some sites, completes the user’s identification for access control.

 

What is Contained in the Packet

Request:           PASS

Request Arg:    f1a2k3user

 

Data Values (hexadecimal): 50 41 53 53 20 66 31 61 32 6B 33 75 73 65 72 0D 0A

 

Data Values in Other Bases

 

ASCII

P

A

S

S

SPC

f

1

a

2

Hexadecimal

5  0

4  1

5  3

5  3

2  0

6  6

3  1

6  1

3  2

Binary

0101 0000

0100 0001

0101 0011

0101 0011

0010 0000

0110 0110

0011 0001

0110 0001

0011 0010

Decimal

80

65

83

83

32

102

49

97

59

 

ASCII

k

3

u

s

e

r

\r

\n

Hexadecimal

6 B

3 3

7 5

7 3

6 5

7 2

0 D

0 A

Binary

0110 1011

0011 0011

0111 0101

0111 0011

0110 0101

0111 0010

0000 1101

0000 1010

Decimal

107

51

117

115

101

114

13

10

 

Programming Hint: The name for this variable in code will be IP_TCP_FTP_PDU_FTP.
2.2.4 IP PDU for the selected ICMP PDU

 

IP PDU > Version for the selected ICMP PDU

 

Field Name: Version

 

Purpose and Definition:  Version is a 4-bit field that indicates the format of the internet header.

 

Field Key:       4 = IPv4

            6 = IPv6

 

Data value (decimal):  4

 

Data values in other bases:

 

Hexadecimal

4

Binary

0100

Decimal

4

 

Programming Hint: The name for this variable in code will be IP_Version_ICMP.

IP PDU > Internet Header Length for the selected ICMP PDU

 

Field Name:  Internet Header Length

 

Purpose and Definition:  The IHL field is a 4 bit field indicating the length of the internet header in 32 bit words, and thus points to the beginning of the data.  The minimum value of a correct header is 5.

 

Field Key:  Not applicable

 

Data value:  The value contained in our field is 20 bytes.  This is the hexadecimal and decimal value of 5 multiplied by 4 bits.

 

Data values in other bases:

 

Hexadecimal

0

5

Binary

0000

0101

Decimal

5

 

Programming Hint: The name for this variable in code will be IP_Version_ICMP.

IP PDU > Type of Service for the selected ICMP PDU

 

Field Name:  Type of Service

 

Purpose and Definition:  Type of Service is an 8-bit field that provides and indication of the abstract parameters of the quality of service desired.  These parameters guide the selection of the actual service parameters when transmitting a datagram through a particular network.

 

Field Key:  The major choice is a three-way tradeoff between low-delay, high-reliability, and high-throughput.

 

 

 

 


Bits 0-2: Precedence

Bit 3: (D)  0 = Normal Delay                1 = Low Delay

Bit 4: (T)  0 = Normal Throughput        1 = High Throughput

Bit 5: (R)  0 = Normal Reliability           1 = High Reliability

 

Precedence:

            111 = Network Control                        011 = Flash

            110 = Internetwork Control                  010 = Immediate

            101 = CRITIC/ECP                             001 = Priority

            100 = Flash Overrided             000 = Routine

 

Data value (hexadecimal): 00

 

Data values in other bases:

 

Hexadecimal

0

0

Binary

0000

0000

Decimal

0

 

Programming Hint: The name for this variable in code will be IP_TypeOfService_ICMP.

 

IP PDU > Total Length of Ethernet Frame for the selected ICMP PDU

 

Field Name: Total Length of Ethernet Frame

 

Purpose and Definition: Total Length is a 16-bit field that indicates the length of the frame, measured in octets, including internet header and data.  The maximum size is 216-1 or 65,535 octets; however, the recommended maximum size is 576 octets.

 

Field Key: Not applicable

 

Data values (decimal):  84

 

Data values in other bases:

 

Hexadecimal

0

0

5

4

Binary

0000

0000

0101

0100

Decimal

0

84

ASCII

©

T

 

Programming Hint: The name for this variable in code will be IP_TotalLength_ICMP.

IP PDU > Identification for the selected ICMP PDU

 

Field Name:  Identification

 

Purpose and Definition:  Identification is a 16-bit field.  An identifying value is assigned by the sender to aid in assembling the fragments of a datagram.  The identifier is chosen based on the need to provide a way to uniquely identify the fragments and protocol for the time the datagram or any fragment could be alive in the internet

 

Field Key: Not applicable

 

Data value (hexadecimal): 00 00

 

Data values in other bases:

 

Hexadecimal

0

0

0

0

Binary

0000

0000

0000

0000

 

Programming Hint: The name for this variable in code will be IP_Identification_ICMP.

IP PDU > Flags for the selected ICMP PDU

 

Field Name:  Flags

 

Purpose and Definition:  Flags is a 3-bit field that indicates directions for fragmentation.

 

Field Key:

Bit 0: reserved, must be 0

Bit 1: (DF)  0 = May Fragment             1 = Don’t Fragment

Bit 2: (MF) 0 = Last Fragment              1 = More Fragment

 

Data value (binary): 010

 

Data values in other bases:  Not applicable

 

Programming Hint: The name for this variable in code will be IP_Flags_ICMP.

 

 

IP PDU > Fragment Offset for the selected ICMP PDU

 

Field Name:  Fragment Offset

 

Purpose and Definition:  The Fragment Offset is a 13- bit field indicating where in the Ethernet frame this fragment begins.  The Fragment Offset is measured in units of 8 octets, and the first fragment has offset 0.

 

Field Key:  Not applicable

 

Data value (decimal): 0

 

Data values in other bases:

Binary: 0 0000 0000 0000

 

Programming Hint: The name for this variable in code will be IP_FragmentOffset_ICMP.

IP PDU > Time to Live for the selected ICMP PDU

 

Field Name: Time to Live

 

Purpose and Definition:  Time to Live is an 8-bit field that indicates the maximum time the datagram is allowed to remain in the internet.  If this field contains the value 0, then the datagram must be destroyed.  This field is modified in internet header processing.  The time is measure in units of seconds, and is set by the sender to the maximum time the datagram is allowed to be in the internet.  This field is decreased at each point that the internet header is processed.  The intention is to cause undeliverable packets to be discarded, and to bind the maximum datagram lifetime.

 

Field Key:  Not applicable

 

Data value (decimal): 64

 

Data values in other bases:

 

Hexadecimal

4

0

Binary

0100

0000

Decimal

64

 

Programming Hint: The name for this variable in code will be IP_TimeToLive_ICMP.
IP PDU > Protocol for the selected ICMP PDU

 

Field Name:  Protocol

 

Purpose and Definition:  Protocol is an 8-bit field that indicates the next level protocol that is used in the data portion of the internet diagram.

 

Field Key:

Dec Hex         Protocol                                                          Dec                 Hex      Protocol

0            00      Reserved                                                          22                    16          Multiplexing

1            01      ICMP                                                              23                    17          DCN

2            02      Unassigned                                                       24                    18          TAC Monitoring       

3            03      Gateway-to-Gateway                                       25-76               19-4C    Unassigned               

4            04      CMCC Gateway Monitoring Message  77                    4D         Any local network

5            05      ST                                                                    100                  64          SATNET and Backroom EXPAK

6            06      TCP                                                                 101                  65          MIT Subnet Support

7            07      UCL                                                                102-104           66-68     Unassigned

10          0A     Unassigned                                                       105                  69          SATNET Monitoring

11          0B      Secure                                                              106                  6A          Unassigned

12          0C     BBN RCC Monitoring                          107                  6B           Internet Packet Core Utility

13          0D     NVP                                                                110-113           6E-71    Unassigned

14          0E      PUP                                                                 114                  72           Backroom SATNET Monitoring

15          0F      Pluribus                                                            115                  73          Unassigned

16        10       Telnet                                                               116                  74           WIDEBAND Monitoring

17        11       XNET                                                              117                  75          WIDEBAND EXPAK

20        14       Chaos                                                              120-376           78-0178  Unassigned

21        15       User Datagram                                     377                  0179        Reserved

 

Data value (hexadecimal): 01

 

Data values in other bases:

 

Hexadecimal

0

6

Binary

0000

0001

Decimal

1

 

RFC Link: http://www.faqs.org/rfcs/rfc790.html

 

Programming Hint: The name for this variable in code will be IP_Protocol_ICMP.

IP PDU > Header Checksum for the Selected ICMP PDU

 

Field Name:  Header Checksum

 

Purpose and Definition:  The Header Checksum is a 16-bit field.  This CRC algorithm is the 16-bit one’s complement sum of all the 16-bit words in the header.  For purposes of computing the checksum, the value of the checksum field is initially zero.  When both header checksums are the same, then the header bits are correct.  If either checksums vary, then a packet will need to be resent.

 

This is a simple way to compute the checksum and experimental evidence indicates that it is adequate, but it is provisional and may be replaced by a CRC procedure, depending on further experience.

 

Field Key:  Not applicable

 

Data value (hexadecimal): B8 CC

 

Data values in other bases:

 

Hexadecimal

B

8

C

C

Binary

1011

1000

1100

1100

 

Programming Hint: The name for this variable in code will be IP_HeaderChecksum_ICMP.

IP PDU > Source Address for the Selected ICMP PDU

 

Field Name:  Source Address

 

Purpose and Definition:  The Source Address is a 32-bit field that contains the IP address of the host that sent the IP Packet.

 

Field Key:  Not applicable

 

Data value:  192.168.0.39

 

Data values in other bases:

 

Hexadecimal

C

0

A

8

0

0

2

7

Binary

1100

0000

1010

1000

0000

0000

0010

0111

Decimal

192

168

0

39

 

Programming Hint: The name for this variable in code will be IP_SourceAddress_ICMP.

IP PDU > Destination Address for the selected ICMP PDU

 

Field Name:  Destination Address

 

Purpose and Definition:  The Destination Address is a 32-bit field that contains the address of the host that is to receive the data contained within the IP packet.

 

Field Key:  Not applicable

 

Data value:  192.168.0.101

 

Data values in other bases:

 

Hexadecimal

C

0

A

8

0

0

6

5

Binary

1100

0000

1010

1000

0000

0000

0110

0101

Decimal

192.

168.

0.

101

 

Programming Hint: The name for this variable in code will be IP_DestinationAddress_ICMP.

 

IP PDU > Options and Padding for the selected ICMP PDU

 

Field Name:  Options and Padding

 

Purpose and Definition:  The options may or may not appear in Ethernet packets.  They must be implemented by all IP modules (host and gateways).  What is optional is their transmission in any particular packet, not their implementation.

 

The option field is variable in length.  There may be zero or more options.  There are two cases for the format of an option.

            Case 1: A single octet of option type

            Case 2: An option-type octet, an option-length octet, and the actual option-data                                    octets.

 

Field Key:  Not applicable

 

Data values:  Not applicable

 

Data values in other bases:  Not applicable

 

Programming Hint: The name for this variable in code will be IP_OptionsPadding_ICMP.

 

 

 

2.2.5 ICMP PDU for the selected ICMP PDU

 

IP > ICMP Header > Type for the selected ICMP PDU

 

Field Name:  Type

 

Purpose and Definition:  The type is an 8-bit field that identifies what sort of message the ICMP protocol is sending.

 

Field Key:

Dec     Hex    Message Type                       Dec       Hex      Message Type       

0          00        Echo Reply                               16          10         Information Reply

1          01        Unassigned                               17          11         Address Mask Request

2          02        Unassigned                               18          12         Address Mask Reply

3          03        Destination Unreachable           19          13         Reserved (for Security)

4          04        Source Quench             20-29     14-1D   Reserved (for Robustness Experiment)

5          05        Redirect                                   30          1E         Traceroute

6          06        Alternate Host Address            31          1F         Datagram Conversion Error

7          07        Unassigned                               32          20         Mobile Host Redirect

8          08        Echo                                        33          21         IPv6 Where-Are-You

9          09        Router Advertisement               34          22         IPv6 I-Am-Here

10        0A       Router Solicitation                    35          23         Mobile Registration Request

11        0B        Time Exceeded             36          24         Mobile Registration Reply

12        0C       Parameter Problem                   37          25         Domain Name Request

13        0D       Timestamp                                38          26         Domain Name Reply

14        0E        Timestamp Reply                      39          27         SKIP

15        0F        Information Request                  40          28         Photuris

                                                                        41-255   29-FF Reserved

 

Data value: 8 (Echo (ping) Request)

 

Data values in other bases:

 

Hexadecimal

0

8

Binary

0000

1000

Decimal

8

 

RFC Link: http://www.iana.org/assignments/icmp-parameters

 

Programming Hint: The name for this variable in code will be IP_ICMP_Type_ICMP.

 

IP > ICMP Header > Code for the selected ICMP PDU

 

Field Name:  Code

 

Purpose and Definition: Code is an 8-bit field that provides further information about the associated type field.

Field Key:

Type     Name                                                                                                  Type     Name
  0             Echo Reply (used by “PING”)                                                       7            Unassigned 
                     0     No Code                                                                                 8            Echo (used by "PING")
  1             Unassigned                                                                                        0     No Code                                                                           
  2             Unassigned                                                                  9            Router Advertisement 
  3             Destination Unreachable                                                                                    0    No Code
                     0     Net Unreachable                                              10           Router Selection
                     1     Host Unreachable                                                                   0    No Code
                     2     Protocol Unreachable                                                          11           Time Exceeded
                     3     Port Unreachable                                                                    0    Time to Live exceeded in Transit
4         Fragmentation needed and                                                                1    Fragment Reassembly Time Exceeded
                Don't Fragment was Set                                              12            Parameter Problem
                     5     Source Route Failed                                                                                    0    Pointer indicates the error
                     6     Destination Network Unknown                                                                1    Missing a Required Option
                     7     Destination Host Unknown                                                  2    Bad Length
                     8     Source Host Isolated                                                           13           Timestamp
9         Communication with Destination                                                     0    No Code
         Network is Administratively Prohibited                  14           Timestamp Reply                   
10      Communication with Destination                                                     0    No Code
         Host is Administratively Prohibited                         15           Information Request             
11      Destination Network Unreachable                                                   0    No Code
         for Type of Service                                               16           Information Reply                    
12      Destination Host Unreachable for                                                    0    No Code
         Type of Service                                                           17           Address Mask Request       
  4            Source Quench                                                                                                        0    No Code
                     0     No Code                                                                                18           Address Mask Reply            
  5            Redirect                                                                                                                    0     No Code
                     0    Redirect Datagram for the Network                                    19           Reserved (for Security)        
                     1    Redirect Datagram for the Host                                          20-29   Reserved (for Robustness Experiment)
                     2    Redirect Datagram for the Type of                                     30        Traceroute
                             Service and Network                                                          31        Datagram Conversion Error
3         Redirect Datagram for the Type of                            32        Mobile Host Redirect
         Service and Host                                                         33        IPv6 Where-Are-You
  6            Alternate Host Address                                             34        IPv6 I-Am-Here
                     0    Alternate Address for Host                            35        Mobile Registration Request 
36        Mobile Registration Reply
       Data value (decimal): 0

 

Data values in other bases:

 

Hexadecimal

0

0

Binary

0000

0000

Decimal

0

ASCII

©

 

Programming Hint: The name for this variable in code will be IP_ICMP_Header_ICMP.

IP > ICMP Header > Checksum for the selected ICMP PDU

 

Field Name:  Checksum

 

Purpose and Definition:  The checksum is the 16-bit one’s complement of the one’s complement sum of the ICMP message, starting with the ICMP type.  For computing the checksum, the checksum field should initially be zero.

 

Field Key:  Not applicable

 

Data value (hexadecimal): C9 15

 

Data values in other bases:

 

Hexadecimal

C

9

1

5

Binary

1100

1001

0001

0101

Decimal

201

21

ASCII

á

©

 

Programming Hint: The name for this variable in code will be IP_ICMP_Checksum_ICMP.

 

IP > ICMP Header > Identifier for the selected ICMP PDU

 

Field Name:  Identifier

 

Purpose and Definition:  The identifier is a 16-bit field that is used in matching echoes and replies for when the code field is zero.

 

Field Key:  Not applicable

 

Data value (hexadecimal): 70 60

 

Data values in other bases:

 

Hexadecimal

7

0

6

0

Binary

0111

0000

0110

0000

Decimal

112

96

ASCII

P

‘

 

Programming Hint: The name for this variable in code will be IP_ICMP_Identifier_ICMP.

 

IP > ICMP Header > Sequence for the selected ICMP PDU

 

Field Name:  Sequence

 

Purpose and Definition:  The sequence is a 16-bit field that is used in matching echoes and replies for when the code field is zero.

 

Field Key:  Not applicable

 

Data value (hexadecimal): 70 60

 

Data values in other bases:

 

Hexadecimal

0

0

0

0

Binary

0000

0000

0000

0000

Decimal

0

0

ASCII

©

©

 

Programming Hint: The name for this variable in code will be IP_ICMP_Sequence_ICMP.

 

IP > ICMP Header > Data for the selected ICMP PDU

 

Field Name:  Data

 

Purpose and Definition:  The data is a variable-length field that contains the actual information that is sent in the ping packet.

 

Field Key:  Not applicable

 

Data value (hexadecimal): 42 B1 89 3F 00 00 00 00 2C C6 07 00 00 00 00 00 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37

 

Data values in other bases:

 

Hexadecimal

4

2

B

1

8

9

3

F

0

0

Binary

0100

0010

1011

0001

1000

1001

0011

1111

0000

0000

Decimal

66

177

137

63

0

ASCII

B

á

á

?

©

 

Hexadecimal

0

0

0

0

0

0

2

C

C

6

Binary

0000

0000

0000

0000

0000

0000

0010

1100

1100

0110

Decimal

0

0

0

44

198

ASCII

©

©

©

,

á

 

Hexadecimal

0

7

0

0

0

0

0

0

0

0

Binary

0000

0111

0000

0000

0000

0000

0000

0000

0000

0000

Decimal

7

0

0

0

0

ASCII

©

©

©

©

©

 

Hexadecimal

0

0

1

0

1

1

1

2

1

3

Binary

0000

0000

0001

0000

0001

0001

0001

0010

0001

0011

Decimal

0

16

17

18

19

ASCII

©

©

©

©

©

 

Hexadecimal

1

4

1

5

1

6

1

7

1

8

Binary

0001

0100

0001

0101

0001

0110

0001

0111

0001

1000

Decimal

20

21

22

23

24

ASCII

©

©

©

©

©

 

Hexadecimal

1

9

1

A

1

B

1

C

1

D

Binary

0001

1001

0001

1010

0001

1011

0001

1100

0001

1101

Decimal

25

26

27

28

29

ASCII

©

©

©

©

©

 

Hexadecimal

1

E

1

F

2

0

2

1

2

2

Binary

0001

1110

0001

1111

0010

0000

0010

0001

0010

0010

Decimal

30

31

32

33

34

ASCII

©

©

SPACE

!

“

 

Hexadecimal

2

3

2

4

2

5

2

6

2

7

Binary

0010

0011

0010

0100

0010

0101

0010

0110

0010

0111

Decimal

35

36

37

38

39

ASCII

#

$

%

&

‘

 

Hexadecimal

2

8

2

9

2

A

2

B

2

C

Binary

0010

1000

0010

1001

0010

1010

0010

1011

0010

1100

Decimal

40

41

42

43

44

ASCII

(

)

*

+

,

 

Hexadecimal

2

D

2

E

2

F

3

0

3

1

Binary

0010

1101

0010

1110

00010

1111

0011

0000

0011

0001

Decimal

45

46

47

48

49

ASCII

-

.

/

0

1

 

Hexadecimal

3

2

3

3

3

4

3

5

3

6

Binary

0011

0010

0011

0011

0011

0100

0011

0101

0011

0110

Decimal

50

51

52

53

54

ASCII

2

3

4

5

6

 

Hexadecimal

3

7

Binary

0011

0111

Decimal

55

ASCII

7

 

 Programming Hint: The name for this variable in code will be IP_ICMP_Data_ICMP.

 

 

 

3.0 Appendix

 

3.1 Glossary

 

ASCII:

            American Standard Code for Information Interchange: a code for representing English characters as numbers, with each letter assigned a number from 0 to 127.

 

Attribute:

            A named value or relationship that exists for some or all instances of some entity and is directly associated with that instance.

           

Binary:

            Pertaining to a number system that has just two unique digits, 0 and 1.  Computers operate on a binary number system.

           

Code:

            The symbolic arrangement of data or instructions in a computer program or the set of such instructions.

 

Data Flow Diagram:

            A graphical notation used to describe how data flows between processes in a system.  They are a representation of the functional decomposition of a system.

 

Decimal:

            Refers to numbers in base 10—the numbers we use in everyday life.

 

Dynamic Combo Menu:

            Menu showing all actions possible at the current moment.

 

Frame:

A feature that divides a browser’s window into separate segments that can be scrolled independently of each other; a single step in a sequence of programmed instructions

 

GUI:

            Graphical User Interface: A user interface based on graphics (icons, pictures, and menus) instead of text; uses a mouse as well as a keyboard as an input device.

 

Gantt Chart:

            A chart that depicts progress in relation to time, often used in planning and tracking a project

 

 

HTML:

            Hypertext Transfer Markup Language: A markup language used to structure text and multimedia documents and to set up hypertext links between documents, used extensively on the World Wide Web.

 

Hexadecimal:

            Refers to the base-16 number system which consists of 16 unique symbols: the numbers 0 to 9 and the letters A to F.

           

Hypertext:

            A computer-based text retrieval system that enables a user to access particular locations in web pages or other electronic documents by clicking on links within specific web pages or documents.

 

Internet: 

            An interconnected system of networks that connects computers around the world via the TCP/IP protocol.

 

Linear Sequential Model:  

            Sometimes called the classic life cycle or the waterfall model, this model suggests a systematic, sequential approach to software development that begins at the system level and progresses through analysis, design, coding, testing, and support.

 

Linux:

            A trademark for an open-source version of the UNIX operating system.

 

Network: 

A group of two or more computer systems linked together.

 

Open-Source:

A method and philosophy for software licensing and distribution designed to encourage use and improvement of software written by volunteers by ensuring that anyone can copy the source code.

 

PHP: 

PHP Hypertext Preprocessor (server-side scripting language)

 

Packet:

A short block of data transmitted in a packet switching network.

 

PDU:

Protocol Data Unit: A packet of data passed across a network. 

 

Protocol:

A set of formal rules describing how to transmit data, especially across a network.

 

Prototype:

            An original type, form, or instance serving as a basis or standard for later stages.

 

RFC:

Request for Comments: One of a long-establish series of numbered Internet informational documents and standards widely followed by commercial software and freeware in the Internet and Unix communities.

 

Software:

The code executed by a computer, as opposed to the physical device which they run on.

 

TCP/IP:

Transmission Control Protocol/Internet Protocol: A suite of protocols for communication between computers, used as a standard for transmitting data over networks and as the basis for standard Internet protocols.

 

UNIX:

A powerful operating system developed at the ATT Bell Laboratories.

 

Use Case:

The specification of sequences of actions that a system, subsystem, or class can perform by interacting with outside actors.

 

Visible Analyst:

Project management software used in Computer-Aided Software Engineering (CASE) to create such illustrations as the data flow diagrams.

3.2 Gantt Charts

 

Fall Gantt Chart:

 

Yearlong Gantt Chart: