 |  |  | 5.11 Module 11 -- TCP/IP Transport and Application Layers |
5.11 Module 11 -- TCP/IP Transport and Application Layers
- TCP/IP transport layer (Wikipedia: Transport_layer)
- flow control
- Transport layer protocols
- Transmission Control Protocol -- TCP (Wikipedia: Transmission_Control_Protocol)
- reliable -- "positive acknowledgment with retransmission"
- bidirectional
- in order
- unacknowledged (timeout) packets are re-transmitted.
- windows -- multiple packets can be sent prior to any acknowledgment being received. Octet
pointers. 4 windows, bi-directional & at both ends. Variable size.
- endpoints -- define a connection (sender IP, port) and (receiver IP, port)
- passive open (server) & active open (client)
- Out-of-band data. interrupts/aborts. URG (urgent) bit in code field.
- Opening and closing connections use "three way handshakes"
- Time determination. Round-trip time measurements.
- Congestion -- "congestion collapse" with too many retransmissions.
- Maximum Segment Size (MSS)
- Transmission Control Protocol -- TCP header (Wikipedia: Transmission_Control_Protocol)
- Source port (16 bits)
- Destination port (16 bits)
- Sequence number (32 bits)
- Acknowledgement number (32 bits)
- Data offset (4 bits)
- Reserved (6 bits)
- Flags/ Control bits (code bits) (6 bits)
- Window (16 bits)
- Checksum (16 bits)
- Urgent pointer (16 bits)
- Options - if any and padding (32 bit multiples)
- User Datagram Protocol -- UDP header (Wikipedia: User_Datagram_Protocol)
- Source port
- Destination port
- Length
- Checksum
- TCP and UDP port numbers /etc/services (Wikipedia: TCP_and_UDP_port_numbers)
- TCP/IP application layer protocols
- (book) DNS (TCP&UDP) HTTP SMTP POP3 FTP
- SSH HTTPS SNMP NTP RPC
- TCP/IP applications
- DNS (TCP&UDP) Domain Name service
- HTTP Web service
- SMTP, POP2, POP3, & IMAP (Interactive Mail Access Protocol) mail service
- FTP insecure file transfer
- TFTP insecure local file transfer (UDP)
- Telnet insecure terminal connection
- SSH secure terminal connections & file transfer
- HTTPS secure web service
- SNMP Network management
- NTP Network time protocol
- RPC Remote procedure call
- A network overview.
- Local router to ISP, DHCP
- Local PC to local router, ARP, DHCP
- URL connecting to remote server, DNS (multiple requests), Routing, HTTP
* Unmodified from Cisco Systems site.
Instructor: Louis Taber, louis.taber.at.pima at gmail dot com (520) 206-6850
My web site in Cleveland, OH
The Pima Community College web site
| | | 5.11 Module 11 -- TCP/IP Transport and Application Layers |