Telecommunications Essentials Chapter 8 The Internet & IP Infrastructure

InternetInternet Basics Time to reach 50,000,000 people Telephone – 74 years Internet – 4 years ARPAARPA – 1969 – develops a distributed data network Bomb resistant network Shared computing resources Developing LANs, paging systems, satellite networks 1980 – TCP/IPTCP/IP Cisco

Internet Organizations No one is in charge ISOC An international non-profit organization Oversees the IETF (designs standards through consensus) Registry organizations ARIN, APNIC, RIPE NCC, IANA, ICANN

Internet Structure An ad hoc internetwork of networks Uses the IP protocol suite Uses routers to move packets between networks Routers operate at OSI Layer 3 Routers know the address of network segments and the various interconnecting paths

Internet Protocols - IPIP Defines the datagram (packet)datagram Connectionless Operates at OSI layer 3 Handles packet forwarding, addressing, error notification Segments the data to 1500 byte chunks (64000 bytes is allowed but never used)

Internet Protocols - UDPUDP Adds application multiplexing & checksum to IP Used for multicasting & VoIPmulticastingVoIP No error correction (the application must provide error correction)

Internet Protocols - TCP TCPTCP – Assigns packet and port numbersport numbers Connection oriented Operates at OSI layer 4 Sets up virtual circuits, flow control, ACK, retransmission

Port Numbers 1 – 65,535 Assigned to user sessions Socket = port number + IP address Identify server applications 21 – FTP 25 – 80 – Web servers Firewalls can use port numbers & IP addresses to control information flow

Other Internet Protocols ICMPICMP - Used by operating systems to send error messages. Ping - sends ICMP Echo Request to determine delayoperating systemsPing IGMPIGMP - Manages the membership of Internet Protocol multicast groupsInternet Protocolmulticast ARPARP & RARP – maps between IP and MAC addressesRARPMAC

Network (Routing) Protocols Used to connect to the service provider SLIPSLIP, PPPPPP Interior - used within autonomous systems OSPF Exterior - used between autonomous systems (service providers) BGP

Routing Protocols Distance VectorDistance Vector – each router sends a copy of its routing table to its neighbor RIP, IXP, RTMP,IGRP Link StateLink State – shares information regarding numbers of hops, line speed, traffic, cost, etc. OSPF, IS-IS, NLSP More reliable, easier to debug, less network traffic

ISPISP Terminology POPPOP – Point of presence GigaPOP NAPNAP – Network access point IXPIXP – Internet exchange point MAEMAE – Metropolitan exchange area Backbone Network NSPNSP – Network service provider Tier 1Tier 1, Tier 2, Tier 3Tier 2

IPv4IPv4 Addressing 32 Bits long 2 Parts – Network ID and host ID 5 Classes Class A – very large networks (126) Class B – medium sized networks (16,384) Class C – small to mid size business (2,097,152 each of which can have 254 hosts) Class D – multicast or mbonembone Class E – experimental CIDRCIDR – Allows blocks of addresses to be grouped together in routing tables

IPv6IPv6 Addressing 128 bits long 2 Parts - 64 bits network ID, 64 bits host ID Uses hexadecimal notation Advantages Improved routing efficiency QoS capabilities Better security mechanisms Deployment Not widely used in the US Required in Japan & far east (3G wireless phones) Moonv6Moonv6 largest multivendor IPv6 network

DNSDNS & TLDTLD Translates host names to IP addresses Local name server – in a company or ISP Domain name resolvers – local computers duplicating root domain servers Root domain servers - 13

IP QoSQoS Present System Best Effort – no guaranteesBest Effort QoS Parameters: Latency Jitter Loss Sequencing Errors Needed for real-time traffic VoIP Video Interactive applications QoS Mechanisms Classification (different kinds of packets) Conditioning (traffic shaping)traffic shaping Queue management (RED)QueueRED Queue scheduling (prioritizing) Queuing Mechanisms Fair queuing Weighted fair queuing Weighted round robin Deficit round robin

IP QoS DiffServDiffServ – Differentiated services Header flags set hop behaviors Defines latency, and jitter IntServIntServ - Integrated services Uses RSVP to reserve bandwidthRSVP Not practical on the internet RSVP-TE used on MPLSRSVP-TEMPLS NSISNSIS – Next steps in signaling