OUTLINE What is a IP?  TCP/IP protocols What is Router?  Host-Based vs. Dedicated Routers What is ip routing and how is it done? Link State Routing Protocols  OSPF (Open Shortest Path First) - OSPF areas - An Example OSPF Graph  IS-IS (Intermediate System-to-Intermediate System) Distance-vector routing protocols  RIP (Routing Information Protocol) - RIP Packet Format  IGRP/EIGRP (Enhanced Interior Gateway Routing Protocol) Routing Table  Contents of an IP Routing Table Routing Types  IGP (Interior Gateway Protocol)  EGP(Exterior Gateway Routing Protocol) Dynamic and Static Routing  Static Routing In Hosts and a Default Route - Advantages and Disadvantages Static Routing  Dynamic Routing and Routers - Advantages and Disadvantages Dynamic Routing What is VOIP-Voice Over IP?  The Motivation and challenge of IP Technology  A Basic IP Telephone System  VOIP is advantages and disadvantages  What is PSTN?  PSTN is advantages and disadvantages  What is VoIP security?

What is IP?  Is a data oriented protocol  Is a network layer protocol in the internet protocol suite  IP address Is unique address that certain electronic devices use in order to identify  Ip address street address or phone number thought

Structure of IP Address and Subnet IP -> a.b.c.d 0<= a,b,c,d =< 255 IP Address exist (4 octet) A system or network card has a one more IP Address The number of last group has a 0 this is Network Address or this number is 255. It is called Broadcast Address.

Structure of Domain and IP Address Structure of IP Address is private because of remembering for easily. -> >

Groups of IP Addresses Class A – 1-126A – 0xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Class B – B – 10xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Class C – C – 110xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Class D – D– 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx default routing 127.x.x.x loopback IP Address Class E include first 4 bits begin 1111 Class D is a Multicast IP Address

Subnet and Subnet Mask Subnet Masks Masks of Bits Class A Class B Class C

Ports FTP HTTP DNS.... Port Port TCPUDP Physical Layer IP & ICMP

TCP/IP  It is the basic communication language or protocol of the Internet  TCP/IP is a two-layer program. The higher layer, Transmission Control Protocol (TCP) The lower layer, Internet Protocol (IP)  TCP/IP communication is primarily point-to-point  Protocols related to TCP/IP include the User Datagram Protocol (UDP) movie TCP

TCP/IP

What is a Router?  A computer networking device that buffers and forwards data packets  Routing occurs at layer 3 (the Network layer) of the OSI seven-layer protocol stack.  Routing is most commonly associated with the Internet Protocol  Router means Connection between different networks... sample example: to

Host-Based vs. Dedicated Routers  Zebra vs. Cisco  In the past vs. now  Cheap vs. expensive  Is no highly optimize switching IP packets vs. highly switching IP packets  Is not high performance vs. high performance  Inflexibility vs. flexibility

What is ip routing and how is it done?  It is an umbrella term for the set of protocols  Refers to selecting paths in a computer network along which to send data.  Routing differs from bridging  The Internet, for the purpose of routing, is divided into Autonomous Systems (ASs).

 Device C is acting as a router between these two networks  If A wants to send a packet to E, it must first send it to C who can then forward the packet to E.

The IP Routing protocols enable routers to build up a forwarding table that correlates final destinations with next hop addresses. These protocols include:  IGRP(Interior Gateway Routing Protocol)  IS-IS(Intermediate System - Intermediate System)  OSPF(Open Shortest Path First)  RIP(Routing Information Protocol)

Link State Routing Protocols OSPF (Open Shortest Path First)  It uses path cost as its routing metric  is perhaps the most widely-used IGP in large networks.

Link State Routing Protocols IS-IS (Intermediate System-to-Intermediate System)  It is a protocol used by network devices (routers) to determine the best way to forward datagrams or packets  It is intended for use within an administrative domain or network  IS-IS uses Dijkstra's algorithm for identifying the best path through the network  Did not prefer

Distance-Vector Routing Protocols RIP (Routing Information Protocol)  Routing Information Protocol  Helps routers dynamically adapt to changes of network connections  The routers exchange network reachability information with their nearest neighbors.  Has number of hop counts 15.  Autonomous system (A.S)  Do not send the subnet mask address

Distance-Vector Routing Protocols IGRP/EIGRP (Enhanced Interior Gateway Routing Protocol)  Is a kind of IGP  Number of hop counts 16  Used with large networks  Classful routing protocol  Maximum number of hop counters 255  Autonomuos System (A.S)  All routers have the same A.S numbers in the same A.S  Send the subnet mask address movie AS

What is Routing Table?  Referring to a database on a router.  Store that routers' information in the database.  Direct forwarding by matching destination addresses to the network paths used to reach them. Contents of an IP Routing Table  Network Destination  NetMask  Gateway  Interface  Metric

IP Routing Table

Routing Types IGP(Interior Gateway Protocol)  Uses a routing metric to choose an optimal path to each destination.  Autonomous system(A.S) is free to choose its own IGP  Provide to change information between different system  Easy to install and operate  Comlex and more traffic

Example of IGP Protocol

Routing Types EGP(Exterior Gateway Routing Protocol)  Finds a path to each destination, but cannot find an optimal path because it cannot compare routing metrics from multiple A.S  Exchange routing informaiton with a router autonomous system (A.S)  Complex to install and operate  More flexibility and less traffic

Example of EGP protocols

Dynamic and Static Routing Static Routing In Hosts and a Default Route  Inflexible  Does not require extra routing software  Mosts host use static routing  Host’s routing table contains two entires: +one for the network to which the host attaches +a default entry that directs all other traffic to a specific router.

Advantages and Disadvantages Static Routing? Advantages of the Static Routing  Simple to configure  Easy to predict small networks Disadvantages of the Static Routing  Does not scale well in large networks  Changes require manual reconfiguration  Cannot be automatically routed around

Dynamic and Static Routing Dynamic Routing  It performs the same function as static routing except it is more robust.  Dynamic routing allows routing tables in routers to change as the possible routes change.  There are several protocols used to support dynamic routing including RIP and OSPF.

Dynamic Routing

Advantages and Disadvantages Dynamic Routing? Advantages of the Dynamic Routing -scalability and adaptability -can grow more quickly and larger -adapt to changes in the network topology Disadvantages of the Dynamic Routing -complex structure

What is VOIP-Voice Over IP? VoIP, Voice Over Internet Protokol  Use circuit-switched telephone networks in the VOIP system.  Is the routing of voice conversations over the Internet or through any other IP-based network.  Have some protocols such as VOIP protocols.(Network Voice Protocol)  Is economic  Essipacially prefered by the companies  Protocols carry voice and data  Use some devices such as Gateway, IP router  ADC(analog to digital converter)  DAC (digital to anlaog converter)  Uses digital place but telephone uses anlaog place.  Less traffic (bandwidth is not busy)

VOIP Advantages and Disadvantages Advantages:  transmission of data, voice & video possible  scalability  cheap  less traffic (bandwith) Disadvantages:  The quality of sound at times become unpredictable  Echo movie VOIP

What is PSTN? PSTN (public switched telephone network)  Is a circuit-switched telephone networks  Gateway provide to change ADC or DAC using PSTN.  More traffic (bandwidth is busy)

PSTN Advantages and Disadvantages Advantages Well established technology Easy maintenance Hassle free set-up process Simplicity in usage procedures Disadvantages Dedicated line required to complete a call Limited scalability Optimum usage of bandwidth not possible Monthly fees applicable for maintenance Higher call charges

What is VoIP security?  Businesses of all sizes adopting IP telephony need to seriously consider its security implications.  Three stand out as the most dangerous, particularly to smaller organisations: denial of service, spit fraud  The majority of consumer VoIP solutions do not support encryption yet.

Sources INTERNET ADRESLERİ KİTAPLAR İnternet - Kürşat Çağıltay Internet working with TCP/IP - Douglas E. Comer Bilgisayar Ağları ve Güvenliği - Alper Özbilen internet teknolojileri - zafer demirkol Computer networks and internets with Internet Applications - Douglas E. COmer Managing IP networks with Cisco Routers - Scott M. Ballew Cisco TCP/IP routing professional reference - Chris Lewis

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