IPv4/6

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IPv4/6

• Nirmala Shenoy
• Information Technology Department
• Rochester Institute of Technology

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Internet Protocol

• Scope
• IPv4 Purpose / Limitations
• IPv4 features
• IPv6 features
• MobileIP
• Integrated services in IP
• Differentiated services in IP

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Internet Protocol

• Purpose
• To connect different types of local networks
• To provide universal communications
• Unique addresses
• To hide underlying NW technology/SW
• Robust system failures and congestion
• Best effort delivery data networks
• No support for timely reliable delivery

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Internet Protocol

• Purpose
• No support for wireless networks
• Data forwarding protocols, with network ids
• No error control / flow control
• ICMP
• Connectionless datagram forwarding

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Internet Protocol

• Layers
• Comprises Layer 3 functions
• Forwarding
• Routing decisions
• Uses routing algorithms

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Internet Protocol

• PDU

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Internet Protocol

• PDU
• VERS version of the IP that created the datagram
  - current version is 4
• IHL Internet header length in 32 bit words
  due to IP options
• TOTAL LENGTH length of datagram in octets

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Internet Protocol

• PDU
• TYPE OF SERVICE
• Precedence (importance of the datagram)
• type of transportation
• D- low delay
• T high throughput
• R- high reliability
• C- minimize cost
• All bits 0 -normal service
•   D, T, R and C help in route selection

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Internet Protocol

• PDU
• IDENTIFICATION unique id for each datagram
• FLAGS
• D datagram may be / may not be fragmented
• M 0 last fragment, 1 more to come
• FRAGMMENT OFFSET

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Internet Protocol

• Fragmentation and reassembly

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Internet Protocol

• PDU
• Time to Live
• PROTOCOL
• Specifies which high level protocol was used to
  create the message, - UDP, TCP
• IP OPTIONS
• Not required in every datagram

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Internet Protocol

• PDU
• 8 possible options
• 0.       end of options list
• 1.       No operation used for aligning octets
  between options
• 2.       Security and handling restrictions
• 3.       Loose source routing
• 4.       Record time-stamp along a route
• 5.       Stream identifier (obsolete)
• 6.       Strict source routing
• 7. Record route

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Internet Protocol

• Routing in Internet

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Internet Protocol

• Routing in Internet

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Internet Protocol v6

• Why IPv6?
• IPv4 address extension using CIDR
• Real time support
• Mobility support
• Flexible and efficient

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Internet Protocol v6

• Aims of IPv6
• support huge amount of addresses
• Reduce size of routing tables
• Simplify protocol router to process packets
  faster
• Better security authentication and privacy
• Handle type of service real-time data
• Aid in multi-castings
• Mobility of host
• Protocol should be upgradable
• Allow for old and new protocols to co-exist

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Internet Protocol v6

• Features of IPv6
• addressing capabilities
• Address size increased from 32 to 128 bits
• More levels of address hierarchy
• Support new anycast address
• Quality of Service Capability
• Label packets for special handling during flow

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Internet Protocol v6

• Features of IPv6
• Header Format Simplification
• Number of fields in header is reduced
• Header is of fixed length
• Fragmentation not allowed at routers
• Only source can fragment

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Internet Protocol v6

• Features of IPv6
• Improved Support for options
• Encoding of the options changed
• Router does not examine options (except
  hop-by-hop options)
• More efficient forwarding
• Less stringent limits on the length
• Greater flexibility for new options

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Internet Protocol v6

• Features of IPv6
• Security
• IP level security
• Authentication and privacy supported

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Internet Protocol v6

• PDU of IPv6

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Internet Protocol v6

• PDU of IPv6
• Priority Traffic class
• Route choosing
• Interactive class low delay
• Real- time path with less than 100ms delay

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Internet Protocol v6

• PDU of IPv6
• Flow Label
• Performance guarantees
• Path establishment id provided
• id to be used in all packets

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Internet Protocol v6

• PDU of IPv6
• Next Header 8 bits
• Id for the header following the IPv6 header
• could identify the additional (optional)
  extension headers if any

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Internet Protocol v6

• PDU of IPv6
• Next Header

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Internet Protocol v6

• PDU of IPv6
• Next header
• Exists in IPv6 header and the Extension Header
• Used to identify the next header
• Extension headers are not processed by any node
  along the packets route (except the hop-by-hop
  options header)

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Internet Protocol v6

• PDU of IPv6
• Destination options
• Fragmentation options
• Authentication
• Payload security
• Hop- by hop options
• Extended routing

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Internet Protocol v6

• Addressing in IPv6
• Unicast an id for a single interface
• Anycast An id for a set of interfaces
• Multicast- an id for a set of interfaces

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Internet Protocol v6

• Addressing in IPv6
• Address Representation hex notation
• X X X X X X X X
• EgFEDCBA579874C87B98AC7654AB5656AB
• 1080000800200C6417A ( leading zeros can be
  omitted)
• 1080800200C6417A

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Mobile Internet Protocol

• MobileIP
• Use of portable computers on the Internet
• Internet connection on migration
• Issues
• IP addressing depends on connection to a network

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Mobile Internet Protocol

• Ex 160.80.40.20
• 160.80 IP address class B network number 8272
• 40.20 is the host number 10260
• Routing tables carry network id
• packets routed based on the network id
• Machine moves to a different network
• IP address changes

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Mobile Internet Protocol

• MobileIP Features - ietf
• Mobile host must to use its home IP address
  anywhere
• No Software changes to fixed hosts
• No Changes to router software and tables
• Most packets for mobile hosts should not make
  detours on the way
• No overheads while Mobile host is at home

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Locate Host
• Forward packet to host at current location

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Locate Host

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Locate Host
• Identify areas LAN, wireless networks
• Each area has a Foreign Agent, Home Agent
• Home Agent
• Responsible for roaming host
• Has the details of its current position
• Will forward messages to roaming host

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Locate Host
• Foreign Agent
• Responsible for foreign host in its territory
• Roaming Host reports to Foreign Agent
• Foreign Agent communicates to Home Agent
• Foreign Agent is the c/o for messages to Mobile
  Host
• Broadcasts itself

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Locate Host
• Foreign Agent
• Roaming user registers giving its home address
• Current data link layer address
• Security information
• FA authenticates from HA
• Gives its address as c/o for the mobile node

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Forwarding packets
• Packets addressed to Mobile host intercepted by
  HA
• HA encapsulates packet into a new IP packet with
  FA as destination and itself as Source and sends
  to FA tunnelling
• FA removes encapsulation and forwards on layer 2
  to roaming mobile

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Forwarding packets
• OR
• HA gives FA address to sender of messages and
  forwards only the first message
• Subsequent messages are tunneled to FA from
  Sender directly bypassing home network

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Mobile Internet Protocol

• Routing to Mobile Hosts
• Forwarding packets

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Integrated Service in Internet

• Proposed Services
• Guaranteed services
• For intolerant applications
• Faithful playback circuit emulation
• Eg critical control appln

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Integrated Service in Internet

• Proposed Services
• Predicted services
• Tolerant to Qos loss
• Predict behavior and requirement from recent past
  
• Flow regulation required
• Best effort services
• Elastic Applications

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Integrated Service in Internet

• Proposed Services
• Achieved through
• Controlled link sharing
• Resource reservation
• Admission control

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Integrated Service in Internet

• Internet proposed solutions
• Stateful Solutions
• Fair queuing under congestion
• Protection to well behaved traffic
• Better utilisation and quality assurance
• Integrated Services support - IntServ
• per flow quality guarantees

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Integrated Service in Internet

• Internet proposed solutions
• Stateless Solutions
• Packet dropping on congestion
• Identify packets into flow aggregates
• Service offered on aggregated traffic
• Scalable and Robust
• Differentiated Services - diffserv

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Integrated Service in Internet

• Intserv support
• Qos Specifications
• Intserv unaware hops
• Available path bandwidth
• Maximum path latency
• Maximum Packet size
• QoS service spec token bucket based

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Integrated Service in Internet

• Intserv support - Router features

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Integrated Service in Internet

• Intserv support - Router features
• Admission Control
• Classifier
• Packet Scheduler
• Reservation set up protocols

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Integrated Service in Internet

• Intserv support - Router features
• Reservation set up protocols
• Helps provide sat up facilities for specific flow
  demands
• Message carries application requirements and goes
  though each and every router to the end node
• If successful in providing resources
• Call accepted
• All routers enroute should handle

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Integrated Service in Internet

• Intserv support - Router features
• Reservation set up protocols
• Routing agents decide on the routes when such
  messages come by
• Passed to Reservation set up agent
• Communicates with the admission control
• Who check if the call can be supported
• If so reservation agents makes bookings

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Integrated Service in Internet

• Intserv support - Router features
• Classifier
• Classifies incoming packets into proper queues
  for appropriate handling
• Classes can be one flow, multiple flows
• All packets belonging to one class are handled
  identically by the scheduler

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Integrated Service in Internet

• Intserv support - Router features
• Packet scheduler
• Schedules based on each flow requirement
• Uses queues and timers
• Priority only
• Weighted fair queuing
• Packet dropping under congestion
• Sets congestion control mechanisms

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Integrated Service in Internet

• Intserv support - Router features
• Estimator
• Measures actual outgoing traffic
• Useful for the admission control
• Policing
• Classifying flows
• Destination address, source address, ports
• Flow-id IPv6

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Differentiated Service in Internet

• Packet are classified into traffic aggregates
• Service provided to traffic aggregates
• Complexity only at boundary nodes
• Classification
• Conditioning
• Shaping
• Interior nodes no states

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Differentiated Service in Internet

• Interior nodes no states
• Per hop behavior (PHB) defined for each traffic
  class
• TOS field used as DS field diffserv field
• Decouples service from applications
• Decouples traffic conditioning and service
  provisioning from forwarding
• Scalable
• Robust

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Differentiated Service in Internet

• DS domain
• Nodes operating within a common service
  provisioning
• Across domains Service Level Agreements

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Differentiated Service in Internet

• Diffserv routers
• Packet classifier
• Classfies
• Forwards to appropriate traffic conditioner
• Traffic conditioning
• Metering, shaping, policing, remarking based on
  subsequent domains

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Differentiated Service in Internet

• Summary
• High popularity
• Limited capability
• Backward compatibility
• Retro-fit?
• Will IPng be the solution?
• Real time support?
• Wireless support?
• High bit rate applications?