DCSP packet checker

This python script facilitates the sending and receiving of UDP packets with specified Type of Service (ToS) values. It can be utilized for testing network performances and examining packet transfer rates under different Quality of Service (QoS) configurations.

• Features: Send Packets with custom ToS values (using DSCP values, ECN always 00) to a specified IP address.

• Receive packets and display some packet information, as its load size and received DSCP value.

• Support for specifying the size of the packet payload.

Prerequisites

• Python3.x installed on your system.

• Requires Python libs:

  • scapy : for crafting and analyzing packets.

  • tabulate : for formatting packet information in a tabular format.

Usage

1. Sending Packets:

   • Execute the script with the '-c' or "--client" flag followed by the destination IP address.

   • use the "--dscp" flag to specify thje DSCP code for the packets.(Required, should be the letter + number code. )

   • Optionally, use the "--inf" flag to send packets continuosly until interrupted.

   • Optionally, you can set the size of the packet load using the "--load" flag. Example: $ python3 typeChecker.py -c 192.168.1.100 --dscp 34 --inf --load 1024

   • Optionally, you can use the --all flag, which will send one packet with each DSCP.

2. Receiving packets:

   • Execute the script with the '-s' or "--server" flag.

   • Optionally, use the "--dscp" flag to specify the expected DSCP code for incoming packets. If not provided, the script will expect the same DSCP value as received. Example: $ python3 typeChecker.py -s --dscp 34

   • Optionally, use the "--timeout" flag to specify, in seconds, how many seconds to await for a packet before timing out and printing a signal to the user. If not provided, the script will wait for 22 seconds.

   • The script will display the received packet information in a tabular format, including the IP address, DSCP value, and packet size.

DSCP Code Options

Below is a list of DSCP (Differentiated Services Code Point) codes along with their corresponding values and names:

DSCP Value	DSCP Code	Name
10	AF11	Assured Forwarding 11
12	AF12	Assured Forwarding 12
14	AF13	Assured Forwarding 13
18	AF21	Assured Forwarding 21
20	AF22	Assured Forwarding 22
22	AF23	Assured Forwarding 23
26	AF31	Assured Forwarding 31
28	AF32	Assured Forwarding 32
30	AF33	Assured Forwarding 33
34	AF41	Assured Forwarding 41
36	AF42	Assured Forwarding 42
38	AF43	Assured Forwarding 43
0	CS0	Class Selector/Default
8	CS1	Class Selector 1
16	CS2	Class Selector 2
24	CS3	Class Selector 3
32	CS4	Class Selector 4
40	CS5	Class Selector 5
48	CS6	Class Selector 6
56	CS7	Class Selector 7
46	EF*	Expedited Forwarding
44	VOICE-ADMIT*	Voice Admit

Please note that the DSCP codes EF and Voice Admit correspond to values 46 and 44, respectively. Additionally, when specifying DSCP codes, use the letter + numerical value, e.g., AF11 should be represented as af11 or AF11. Numbers could be used. So, AF could be represented as 11, but for better practice, use the entire code.

Notes

• The script uses UDP packets and listens on port 12345 for incoming packets.

• Packet payload is "Hello, this is a test message", which is 29 bytes long, unless a specific size is provided, which then will be random generated data.

• The script supports DSCP values ranging from 0 to 56. DSCP values outside this range will be ignored.