UDP based implementation of Reliable Data Transfer (RDT) Protocols
- Jacob Cherry
- Eric Kang
- Seshen Fraser
| RDT Header | TCP Header | Reasoning |
|---|---|---|
| 8-bit Sequence Number | 32-bit Sequence Number | Project requirements list 8-bit sequence numbers. Required for robust RDT. |
| 8-bit Acknowledgement Number | 32-bit Acknowledgement Number | Matches the sequence number. Used for ACKing packets. |
| FIN Flag | FIN Flag | Used to teardown the connection |
| SYN Flag | SYN Flag | Used to establish the connection |
| RST Flag | RST Flag | Used to abort connection on an error |
| ACK Flag | ACK Flag | Used to acknowledge packets |
| 8-bit Receiver Window | 16-bit Receiver Window | Decided to use the receiver window to count packets, rather than bytes, so that a smaller number can be used. It's also 8-bit so that the header divides into 16-bit words evenly for checksum calculation. |
| 16-bit Checksum | 16-bit Checksum | Used for error detection, necessary for RDT. |
| TCP Header | Reasoning |
|---|---|
| Source Port | This will be received from UDP through recvfrom(). |
| Dest Port | Any message arriving at the UDP socket will have a known destination port. |
| Header Length | Fixed length headers are easier, so this header is fixed length and therefore doesn't require an embedded length field. |
| PSH Flag | This isn't necessary for our requirements. |
| URG Flag | We assume that packets will never need to be marked as urgent |
| Urgent Pointer | We don't use the URG flag, so it is irrelevant. |