1 Internetworking : Internet architecture and TCP/IP Protocol TK3133 Computer Networking Technology

2 Introduction Internetworking : –Concept –Architecture –Protocol

3 Introduction In the real world, computer is connected to various technology of LAN and WAN In reality, network is heterogeneous – various network (and it is not homogeneous) Contain millions of networks which connected to high-speed backbone Each systems should adapt to various technology Introduce to internetworking concept

4 Internetworking Internetworking is a schema for connecting various network with different technology Use both hardware and software Additional hardware are placed between network Software is in the computer that is connected with Connected networking system is called internetwork / internet Also called as virtual network

5 Internetworking Why different network ? –Network differ with different protocols –Install own network –Different network use different technology Internetworking Scenario

6 Internetworking

7 Network differences

8 Physical network connection using router Router is a component or hardware device which is used to connect networking Router has more interface on various networking Router send and deliver packet between networks Change the packet if necessary to fulfill the standard of each network with different technology (is also called as gateway)

9 Router Example of two physical networks connected to a router that contain 2 different interfaces for each network connection

10 Internet architecture internetwork consist of various networks connected through router (Network can be LAN or WAN)

11 Internet architecture Router can have more that two interfaces

12 Internet The internet concept. (a) The illusion of a single network that TCP/IP software provides to users and applications, and (b) the underlying physical structure in which a computer attaches to one physical network, and routers interconnect the networks

13 Internet seen by TCP/IP

14 Protocol for Internet TCP/IP is the most popular internetworking protocol The first internetworking protocol Maintain by ARPA and taken over by NSF Independent to platform and manufacturer

15 TCP/IP layer OSI 7-layer model not include internetworking Model TCP/IP layer model contain 5 layers

16 TCP/IP layer and OSI model

17 TCP/IP Layer Layer 5: Application Similar to layer 5,6 and 7 in OSI model Layer 4: Transport Similar to layer 4 in OSI model ; provide reliable transmission of data Layer 3: Internet Define standard format packet sent through network with different technology and provide mechanism for packet transmission by router

18 TCP/IP Layer Layer 2: Network interface Similar to layer 2 in OSI; define framework format Layer 1: Physical Similar to layer 1 in OSI; define basic of network hardware

19 Host, Router and Protocol Layer Host computer is any computer system connected to internet and perform application TCP/IP allow the hosts at internet have direct communication Both host and router needs TCP/IP stack Host normally has an interface and is not forwarding packet Router forwards packet but does not need layer 4 and 5

20 Network Layer Internet Protocol (IP) How to manage network in network? –Use network layer protocol called as Internet Protocol (IP) –Enable for a procedure running on a computer sending data to application procedure that running on other computer at another distance network

21 Internet Protocol (IP) IP responsible for providing best-effort transmission for packet (or datagram) How is the communication in the Internet ? –Transport layer takes data flow and divides them into datagram –Network layer send each datagram through Internet. Division into smaller unit may happen during this process.

22 Internet Protocol(IP) –At the destination, datagram is re-gathered by network layer to original datagram and is sent to transport layer Best-effort does not guarantee in managing datagram overlapping problem, slow or not-sequence transmission, lost and corrupted data Service that offered by IP is without connection IP define hardware-free packet format that can be sent called Datagram IP

23 Datagram IP IPv4 defines datagram at maximum 64Kb Head format datagram IP

24 Head Protocol of IPv4

25 Datagram IP Format FIELDDescription VERSIONVersion number of datagram IP IHLENWhat is the length of datagram IP head TOSType of services offered Total LengthWhat is the length of datagram

26 IP Protocol FieldDescription IdentificationUnique identification to datagram Fragment OffsetOffset for fragment Time To LiveCounter to maximum number of datagram longevity ProtocolGive protocol to top layer ChecksumDefine genuine of head Source/destination address Full address of source/destination node OptionMay be contain security option

27 Fragmentation Each network technology define the maximum data that can be sent in a packet. This limitation called MTU (Maximum Transmission Unit). When a router accept a datagram that bigger than MTU, router would fragment datagram into smaller fragment Each fragment is sent to a destination that responsible to match/reconnect the original datagram

28 Fragmentation a) Transparent fragmentation b) Nontransparent fragmentation

29 Fragmentation Fragmentation when the elementary data size is 1 byte. (a) Original packet, containing 10 data bytes. (b) Fragments after passing through a network with maximum packet size of 8 payload bytes plus header. (c) Fragments after passing through a size 5 gateway.

30 Address issue Main aspect in virtual network is a standard address format Cannot use hardware address because different technology use different address format Address format should independence to any address format of hardware address Sending Host place internet destination address in packet/datagram Router check destination address and send packet to destination

31 TCP/IP address Addressing in TCP/IP defined by Internet Protocol (IP) Each host assigned to a 32-bit number Called IP address or Internet address Unique to throughout Internet Each datagram contain IP address of source and destination

32 IP address Each IP address divided into two categories : network number (prefix) and host number (suffix) Network number shows physical network in which computer connected Host number shows unique number of computer at network Address format enable routing to be efficient

33 Define IP address From 32-bit, some bit assigned to prefix and some to suffix Prefix bigger, suffix smaller - many network, few host at network Prefix smaller, suffix bigger - few network, many host at network Because there are various technology, should allow smaller and bigger networks

34 Address classification Various address format to allow both small and big prefix Each format called an address class A class is identified through the first four bit

35 Class Format of IP address

36 IP address

37 Using class IP Class A, B and C are primary class –Used to normal host addressing Class D for multicasting, a form of limited broadcast Class E specify for future use

38 Dotted Decimal Notation IP number is binary number 32-bit. To make it easier dotted decimal notation is used 32-bit number defined as 4 section 8-bit in decimal number and use dot to separate section To identify class from decimal number, can use address range

39 Dotted Decimal Notation

40 Dotted Decimal Notation

41 Class Range from IP address

42 Number of networks and hosts

43 Example of class addressing Example of assigning IP address to host

44 Subnet Able to divide the network into sub-network Example: a platform has one IP address class B assigned to network but has two or more physical network. Only local router know about various subnet and how to send data to it, other routers know only that there is just one network.

45 Subnet A campus network with LAN for various departments

46 Subnet A network class B has 64 subnet Needs additional information to differentiate between prefix and suffix called subnet mask

47 IPv6 128 bit address Head is more easier More service supports Security

48 IPv6 Head

49 Internet control protocols As addition to IP, Internet network layer has several control protocol : –Address Resolution Protocol (ARP) –Reverse Address Resolution Protocol (RARP) –Internet Control Message Protocol (ICMP) –Internet Group Management Protocol (IGMP)

50 Address Resolution Protocol (ARP) Connection between host using IP address, but connection at data link layer using MAC address This protocol used for finding MAC address for NIC that used by host with certain IP Send request by broadcast –Host with IP will response

51 Address Resolution Protocol (ARP)

52 Reverse ARP (RARP) Normally used by diskless computer. When it is booted from ROM, MAC address is known and want to know its IP address. It can only be used in the same segment.

53 Internet Control Message Protocol (ICMP) Used for configuration and IP networking (due to unreliability of IP) Can give feedback about network problems Type of message –Destination unreachable –Time to live (TTL) exceeded –Parameter problem (header unknown)

54 Internet Control Message Protocol (ICMP) –Redirection –Response to request ( ping packet) –Response to request with time feedback (ping needs time info (timestamped) Use IP, so it can act by its own –Example of instruction that used ICMP Ping and Traceroute

55 Internet Control Message Protocol (ICMP)

56 Internet Group Management Protocol (IGMP) The IP protocol can be involved in two types of communication: unicasting and multicasting. The IP protocol can be involved in two types of communication: unicasting and multicasting. IGMP is one of the necessary, but not sufficient, protocols that is involved in multicasting. IGMP is one of the necessary, but not sufficient, protocols that is involved in multicasting. IGMP is a companion to the IP protocol. IGMP is a companion to the IP protocol.

57 IGMP There are two phases : –Phase 1 : when a host become a member of a multicast group, it send a IGMP message to multicast group address to declare its membership. Local multicast router receives message and inform member information to other multicast router in internet

58 IGMP –Phase 2 : because the membership is dynamic, multicast router periodically should poll for host in local network to certify whether any host is still active or not. If not active, inform to other multicast router.