TOBB ET Ü B İL 55 2 Internet Architecture Lecture 0 1. Mehmet Özdem. Course Topics. Telecomunication Sector Internet Basics / OSI Model Routing Protocols Protocols (TCP,UDP,RTP,RSVP) Internet Access Types Servers (FTP, Mail,www…) NGN (Voice over IP) IPTv. Telecom Market. Chapter 1.
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TOBB ETÜ BİL 552Internet ArchitectureLecture 01 Mehmet Özdem
Course Topics • Telecomunication Sector • Internet Basics / OSI Model • Routing Protocols • Protocols (TCP,UDP,RTP,RSVP) • Internet Access Types • Servers (FTP, Mail,www…) • NGN (Voice over IP) • IPTv
Telecom Market Chapter 1
Oyuncular • v * BTK İnternet Sitesi Yayınlar Bölümünden Alınmıştır
CISCO • KRON • HUAWEI • ERICSON • ALCATEL • ZTE • NORTEL • NOKIA SIEMENS • BIRTEL
İstihdam * BTK İnternet Sitesi Yayınlar Bölümünden Alınmıştır
İstihdam * BTK İnternet Sitesi Yayınlar Bölümünden Alınmıştır
İstatistikler * BTK İnternet Sitesi Yayınlar Bölümünden Alınmıştır
İstatistikler * BTK İnternet Sitesi Yayınlar Bölümünden Alınmıştır
Mobile * BTK İnternet Sitesi Yayınlar Bölümünden Alınmıştır
Number of Internet Users Some interesting statistics
Background • 1962- Licklider (M.I.T) discussed Galactic Network • 1965- 2 PC were spoken eachother(M.I.T) • 1969- DARPA (Defence Advanced Research Project Agency) was the top of American Military Project, in which ARPANET was developed communicating 4 network (University of California at Los Angeles Stanford Research Institute ,University of Utah and University of California at Santa Barbara)
1971-NCP (Network Control Protocol) was developed • 1972- First e-mail was sent • 1983-TCP/IP was developed and used in ARPANET • 1986- American National Science made huge amount of investment on ARPANET installing 5 super computer center called NSFNET
1987-NSF established very powerfull backbone speed of 1.5Mbps • 1994-110 Country,10K network, 3M PC,25M user • 1995-www was used • ……. • 2010- 1.8 Billion of user, 247 Billion e-mail are sending everyday,234 M web sites
Internet Organizations • http://www.itu.int/en/pages/default.aspx • IETF- Internet Engineering Task Force • Performs protocol engineering and development functions • IAB- Internet Architecture Board (formerly Advisory) • Consists of chairs of Task Forces • Responsible for defining the overall architecture • IESG- Internet Engineering Steering Group • Responsible for Internet standards process (RFC) • ISOC- Internet Society • Professional Membership organization • Deals with network issues • IANA- Internet Assigned Numbers Authority • In charge of distribution of IP addresses as well • as all other unique parameters
SomeTerminology • In a LAN a number of End System (ES) or hosts are connected together. This is a connection to a same type of LAN • It is also possible to connect a number of stations to LANs • and then connect these LANs together. This latter approach is called internetworking and each network connected to an inter-network or internet is a subnet • Networks are connected together either through routers or gateways. A router does not usually involve protocol conversion whereas a gateway usually involves protocol conversion
InternetworkingIssues Network Service: The service can be connectionless or connection oriented . Usually LANs offer a connectionless service whereas WANs use connection oriented protocols. Internet is made up of different networks hence connectionless and connection oriented services coexist Addressing: In a network each machine has a unique MAC layer address which is used to identify the ES(End System) in the network. In the Internet since it is made up of different types of networksthe format of the PA (Point of Attachment) address will be different hence a new set of addresses are used.
Routing: In an internet the address does not necessarily refer to a machineconnected to the same network. Routers are used to transfer thepackets to other networks and finally to the destination ES.The routers are addressed in exactly the same way as the ES’shence since they are connected to more than one network theyhave an address related to each of the networks they are connected. Quality of Service QoS state the expected delay, protection required, error, cost (in terms of routing) and priority associated with the NSDU.In connection oriented services this is set in advance, with connectionless no such arrangement.This issue to be resolved in an internet.
Maximum Packet Size Maximum packet size in different networks depend on Bit error rate: As the size of the packets are reduced the probability of a packet being in error is also reduced. Transit Delay: The delay for packets are increased with the packet size Buffer storage requirements: The smaller packets require smaller buffers
Flow and congestion control: • Flow control is regulating the flow of packets between the sourceand the destination such that the destination receives them at thesame rate the source sends. • Congestion control deals with controlling the number of packetscirculating in the system such that the total number does notexceed the system resources. • With connection oriented services flow control methods based onwindows is used. • With connectionless services the network layer does not performany flow control, this function is the responsibility of the transport layer
Addressing Structure of Internet IP IP addresses consist of a 32-bit number, usually written in dotted-decimal notation. The“decimal” part of the term comes from the fact that each byte (8 bits) of the 32-bit IP addressis shown as its decimal equivalent. The four resulting decimal numbers are written in sequence,with “dots,” or decimal points, separating the number hence the name dotted decimal. Forinstance, 188.8.131.52 is an IP address written in dotted-decimal form; the actual binary version is 10101000 00000001 00000001 00000001. Each decimal number in an IP address is called an octet. The term octet is just a vendorneutralterm for byte. So, for an IP address of 184.108.40.206, the first octet is 168, the secondoctet is 1, and so on. The range of decimal numbers in each octet is etween 0 and 255,inclusive.
ClassBasedAddressing RFC 791 defines the IP protocol, including several different classes of networks. IP definesthree different network classes for addresses used by individual hosts addresses calledunicast IP addresses. These three network classes are called A, B, and C. TCP/IP definesClass D (multicast) addresses and Class E (experimental) addresses as well.
Class A addresses A Class A address used the first eight bits of the bit pattern to identify the network that an address belongs to. Class A addresses began with numbers in the range of 1-126 (0 and 127 are reserved).2^7-2=126 networks, 2^24-2=16.777.214 hosts 32-bit representation of Class A address
Only eight bits of the bit pattern were used to identify the network with a Class A address, and the rest of the pattern was used to identify individual hosts on each network. Few organizations could make efficient use of a Class A address. Approximately half of the available Class A addresses were never assigned, and many of the assigned addresses are being "returned" to be used in the Classless InterDomain Routing (CIDR) scheme.
Class B addresses If the first octet of the network number fell between 128 and 191, the network was said to be a "Class B" network. The first two octets of a Class B address identified the network, and the remaining 16 bits identified individual hosts. The Class B address space accommodated 16,384 (2^14) networks and 65,534 (2^16-2) hosts on each network. 32-bit representation of Class B address
Class C addresses The Class C address space covered addresses beginning with numbers in the range of 192 to 223. A Class C address used 24 bits of the pattern to identify the network and the last eight bits to identify the host. This yielded 2.097.152 (2^21) networks with 254 hosts 32-bit representation of Class C address
Class D and class E addresses Class D addresses didn't identify networks. They identified a special addressing mode called multicast addressing. The range for Class D addresses fell between 224 and 239. Class E addresses were reserved for "future use." They were used experimentally in some cases. Their addresses ranged from 240 to 254. The network number 255 was and still is special. It is used to designate subnet masking and broadcast information, and therefore is not used as a network number.
· Internet Address Authority - addresses for networks which willinterconnect with the global Internet must be unique they are obtained from an Internet Service Provider the ISP obtains network addresses from the Internet Assigned Number Authority (formerly known as the NIC - Network Information Center) which has international authority over all Internet addressing · For a private internet - addresses can be chosen locally by a system administrator · Theoretically address class is chosen based on the number of machines which will be on each network but with nearly all Class A and B addresses assigned, only Class C is availableuntil the internet address space is expanded
Private IP Adresses Some computers will never be connected to the Internet. So, engineers building a networkconsisting of only such computers could use IP addresses that are duplicates of registeredpublic IP addresses in the Internet. So, when designing the IP addressing convention forsuch a network, an organization could pick and use any network number(s) that it wanted,and all would be well. However, using the same IP addresses used by another company is unnecessary in thissituation, because TCP/IP RFC 1918 defines a set of private networks that can be used forinternetworks that do not connect to the Internet.
More importantly, this set of privatenetworks will never be assigned by ICANN to any organization for use as registered publicnetwork numbers. So, when building a private network, like one in a lab, you can usenumbers in a range that is not used by anyone in the public Internet.
Subnetting Sometimes, it's convenient or efficient to break an IP address block into smaller sections. By using smaller sections the router will think of the address block as some set of smaller networks, rather than one large network. It is possible to subdivide one network with 256 addresses in half. We could send half of our traffic along one route, and half along another. In that sense, there are now two networks with 128 hosts each. These miniature address blocks are called "subnetworks" or subnets for short.
For this example: ISP gives our company 220.127.116.11/24 , We have 30 hosts in network-1 and 25 hosts in network-2 , make IP design using first 2 subnets and specify each broadcast and network addresses. 30 or 25 users mean 5 host bits, 3 subnet bits 18.104.22.168 (network address -22.214.171.124 (broadcast address) first subnet with /27 mask 126.96.36.199-188.8.131.52 second subnet with /27 mask …. 184.108.40.206-220.127.116.11 last subnet with /27 mask
For this example: A computer at an office has the IP address 18.104.22.168. In binary, that address looks like this: 11000110 01101100 00111100 10000001 At this office, the internal router must be told how much of that string of numbers identifies the network and how much of that string identifies the host. When a Class C network is not subnetted, the first three octets indicate the network and the last octet indicates the host. With no subnets, and the last eight bits identifying the host, the default subnet mask of 255.255.255.0 is used. In binary, it looks like this: 11111111 11111111 11111111 00000000
The subnet mask tells the router inside the network which of those 32 bits represent the network number and which represent the host number. Then, the router compares the address it was given to the subnet mask. Any bit set to 1 in the subnet mask allows the bits in the network address to "fall through" the mask. Any bit set to zero in the subnet mask blocks the number from appearing in the network address. 11000110 01101100 00111100 10000001 (22.214.171.124) 11111111 11111111 11111111 00000000 (255.255.255.0) 11000110 01101100 00111100 10000001 (126.96.36.199) One network is identified and the address above identifies host number 129 on that network.
Two subnets Suppose, the network is divided into two subnets. Two subnets allow us a choice of two paths for the data to travel. Each of those paths can hold a maximum of 128 hosts. The router must be told to split traffic along two paths. Therefore, a different subnet mask must be used than we used in the example above. To divide our Class C network into two pieces, a subnet mask that looks like this is used: 11111111 11111111 11111111 10000000 The 25th bit is now allowed to "fall through" the subnet mask and it determines whether a host is on Network 0 or Network 1.
11000110 01101100 00111100 10000001 (188.8.131.52) 11111111 11111111 11111111 10000000 (255.255.255.128) 11000110 01101100 00111100 10000001 (184.108.40.206) The host is either on Network 0 or Network 1. By looking at the range of addresses, see that Network 0 supports the addresses from 0-127 and Network 1 supports the host addresses from 128-255. (Remember that each subnet has 128 hosts apiece.)