1 / 43

DETAILS OF PROTOCOLS

DETAILS OF PROTOCOLS. The Zoo Protocol TCP IP. A programmer can create Internet application software without understanding the underlying network technology or communication protocols - we will take a different approach Understanding the Zoo Protocol. Transmission Control Protocol (TCP).

shirleyc
Download Presentation

DETAILS OF PROTOCOLS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DETAILS OF PROTOCOLS The Zoo Protocol TCP IP ravie@ftsm.ukm.my

  2. A programmer can create Internet application software without understanding the underlying network technology or communication protocols- we will take a different approachUnderstanding the Zoo Protocol

  3. Transmission Control Protocol (TCP)

  4. Protocol at transport layer • Sending message from client process to server process • How client process could access services from server process? • Inter-process communication is carried out through protocol port

  5. Protocol Port • Port number is assigned to process by operating system • There are 216 ports (0 to 65535) • There are 2 sets of port • for UDP protocol • for TCP protocol

  6. Port well-known (1 – 1023) • For standardized • HTTP [80], SMTP[25], FTP[21, 22], POP3[110], Telnet [23] • Ephemeral port (1024 – 65535) • Assigned dynamically • Assigned to client process • When client process complete, port will be released • The complete assigned list of ports can be seen with instruction /etc/services (at *nix)

  7. Host sun1.ftsm.ukm.my/etc/services

  8. Transmission Control Protocol (TCP) • Provide reliable sending services • Use protocol port for addressing process • For application that needed trust such as: telnet, http, ftp etc.

  9. Header Format of TCP

  10. TCP connection • TCP connection is identified with the last point (port number) of the connection • To establish the connection, TCP needs both ways cooperation • Client will request a port from server • Server will open the port to start the connection

  11. Three-Way Handshaking • TCP uses three-way handshaking while starting and ending connection to provide reliability • Determine that both nodes are ready as well as to put the sequence number in order to synchronize the connection

  12. Starting TCP connection • Use SYN segment to create a connection • Host 1 sends SYN segment and random sequence number • Host 2 reply to SYN segment, by sending ACK to Host 1 and random sequence number • Host 1 reply with ACK

  13. Ending TCP connection • TCP uses FIN segment for ending the connection • Four-way handshaking

  14. User Datagram Protocol (UDP) • It is a transport protocol • Provide communication without unreliable communication • Packet may be lost or it is not following the sequence • No intermediary– receive data from application and immediately send it • Used when no error control needed. • For process such as : DNS [53], echo [7], tftp [69], SNMP[161]

  15. UDP Datagram Format • Header • Source UDP Port (16 bit) • Destination UDP Port (16 bit) • UDP message length (16 bit) • UDP Checksum (16 bit) • Data

  16. Internet Protocol (IP)

  17. IP • Protocol at network layer • Provide packet sending via communication without connection • Use IP for addressing • Determine packet flow through one and more leap (hop) throughout the flow • Provide mechanism that includes • Data unit which called IP datagram • Software to send datagram • Method how host computer process datagram

  18. Figure 19.2Links in an internetwork

  19. IP responsible in providing best-effortsendingfor packet/datagram • How about the communication in the Internet ? • Transport layer takes data flow and divided them into datagram • Transport layer send each datagram through Internet. Division into smaller units could occur during this process • At the destination, datagram will be regrouped by network layer to the original datagram and send it to transport layer

  20. Figure 19.4Network layer at the source

  21. Figure 19.5Network layer at a router

  22. Figure 19.6Network layer at the destination

  23. Addressing • Need a standard address format • Address format must not dependent to hardware address format • Address must be unique throughout the network (Internet) • Body that regulate address registration– Internet Information Center (InterNIC)

  24. IP address (IPv4) • Represented by 32-bit integer • Use dotted decimal quad notation • Consist of 4 parts of 8 bit • Divided by dot

  25. Network class • IP address is organized according to network class • Class A: 0nnnnnnn.iiiiiiii.iiiiiiii.iiiiiiii • Class B: 10nnnnnn.nnnnnnnn.iiiiiiii.iiiiiiii • Class C: 110nnnnn.nnnnnnnn.nnnnnnnn.iiiiiiii • Class D: 1110bbbb.bbbbbbbb.bbbbbbbb.bbbbbbbb • Class E: for future use • Representation: • n – network number • i – host number • b – group id

  26. Address range to identify the class

  27. Each IP address divided into two parts • Network number (prefix) – shows physical network that connected the computer • Host number (suffix) – shows computer unique number at the network • Internet Corporation for Assigned Names and Numbers (ICANN) responsible for assigning class A, B and C to organisation

  28. Class A, B and C are primary class • Used for normal host addressing • Class D is to multicast, • For broadcasting message • Class E is especially for future use • Each host has virtual interface address which is known as loopback interface as 127.0.0.1 • Also known as localhost

  29. Figure 19.19A network with two levels of hierarchy

  30. Limitations in IP addressing system • Some host has more than one address • Network class is too rigid • Not enough IP address for future development

  31. Subnet • IP address is organized as subnet to simplify network management • Each subnet is a set of address that determine by • Subnet address (exp: 199.17.35.96) • Subnet mask (exp: 255.255.255.240)

  32. Subnet A campus network consist of LAN for different departments

  33. Figure 19.20A network with three levels of hierarchy (subnetted)

  34. Figure 19.21Addresses in a network with and without subnetting

  35. Exp of Subnet For network of Class B: • 3 bit is used as subnet to turn it into 15 subnet • subnet mask: 255.255.224.0 • Other 13 bits represent host

  36. Routing • If destination host is not at the same network, datagram will be sent to gateway • How would IP choose its pathway to send datagram to remote network? • Using routing table that contain next hop information– that the other nod connected directly to gateway

  37. Example of routing tablenetstat -nr $ netstat -nr Routing Table: IPv4 Destination Gateway Flags Ref Use Interface -------------------- -------------------- ----- ----- ------ --------- 202.185.46.0 202.185.46.197 U 1 25591 hme0 224.0.0.0 202.185.46.197 U 1 0 hme0 default 202.185.46.254 UG 1 80525 127.0.0.1 127.0.0.1 UH 3 137862 lo0

  38. Figure 19.31Default routing

  39. Internet Protocol Version 6 (IPv6) • AKA Internet Protocol next generation (IPng) • Address length added to 128 bit • Allow Web host addition to Internet • Allow Internet advancement

  40. Diagnostic tools • ping • To test connection to host • Measure round trip time • traceroute (microsoft: tracert) • Show data flow from host to destination • http://www.traceroute.org/ • netstat -nr • Show routing table

  41. ipconfig (microsoft) • ifconfig -a (pd *nix) • To show IP, subnet and computer gateway

  42. Tools • hostname • Computer name • domainname • Domain name • nslookup • Network and Server Information Tools from Myloca (Telekom Malaysia) http://www.myloca.net/cgi-bin/trace/index.pl

More Related