Instant Messaging

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INFOTECH Seminar Advanced Communication
Services Mentor Dr. Stephan Rupp

• Instant Messaging
• Architectures and Concepts

Linan Zheng
07.07.2005 Institute of Communication Networks
and Computer Engineering University of Stuttgart
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Motivation
Linan's happy life with MSN
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Agenda

• Introduction
• What is IM system?
• Presence awareness
• Jabber
• What is Jabber?
• Architecture
• Protocol
• Client/Server interaction
• Other popular IM system
• Features
• Comparison
• Conclusion

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Concepts and Development of IM

• An Internet-based
• protocol application
• Real-time communication
• Business opportunity
• Two directions
• Integrated services
• data transmission
• voice chatting,
• video conference,
• e-mail ,etc
• more flexible mobility

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Presence Awareness

• Presence indicates the state that
• a user or application is in
• Such as online, sleeping, dating,
• on vacation, meeting, at office
• Let other peers know are you
• available to have a conversation
• or other kind communication
• Can convey place, current event,
• activity or any other state you
• wish to share

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Agenda

• Introduction
• What is IM system?
• Presence awareness
• Jabber
• What is Jabber?
• Architecture
• Protocol
• Client/Server interaction
• Other popular IM system
• Features
• Comparison
• Conclusion

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What is Jabber?

• An open-source XML-based messaging platform
• Uses a worldwide distributed network, utilizing
  many
• interconnected servers
• Decentralized Anyone can run their own Jabber
  servers
• Security Any server can be isolated with public
  Jabber network
• Initially designed as a universal instant
  messaging
• platform by gateways, to connect users of
  AOL, MSN, ICQ
• and other IM systems to each other

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Jabber Architecture

• Client/Server, modelled closely after the
  internet mail system
• Server handles user authentication and stores
  information about users, including the contact
  list
• A Jabber user id closely resembles an email
  address
• Alice_at_Jabber.org
• Server contains a component called Etherx,
  translation between different servers and
  messaging systems

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Jabber Protocol

• XMPP (eXtensible Messaging Presence Protocol )
• An XML-based protocol for delivering instant
  messages and presence
• information in near-real-time between
  presence-aware entities in a
• Jabber network
• Include security, authentication, privacy, and
  access control, localization and
  internationalization (RFC2778, RFC2779)
• Only three basic Stanzas
• message (client-to-client conversations)
• iq (query messages)
• presence (used to update a clients availability)

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Client/Server Interaction

• Connecting
• Authentication/ Login
• Inform Presence
• Sending and Receiving Messages
• Ending Session

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Roster and Subscription

• Roster(contact list)
• Store on the server so that the client can
  access it
• Main opperations
• Retrieve roster information
• Add a new item
• Delete an existing item
• Update roster information
• Subscriptions
• An agreement to forward presence changes to the
  subscriber
• Categories
• To sends your presence info to another
  entity
• From receives presence info from
  another entity
• Both both sends and receives presence
  info
• None neither send or receive presence
  info

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Agenda

• Introduction
• What is IM system?
• Presence awareness
• Jabber
• What is Jabber?
• Architecture
• Protocol
• Client/Server interaction
• Other popular IM system
• Features
• Comparison
• Conclusion

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ICQ

• I seek you - one of the first IM, still
  popular
• Great functionalities
• Operates in a server-based, peer to peer fashion
• Two main types of communication Client/Server
  and Client/Client

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MSN Messenger

• The most popular instant messaging service
• Tight integration between Hotmail, .NET Passport
  and MSN accounts
• Three kinds of servers
• Dispatch Server (DS), Switchboard Server
  (SS), Notification Server (NS)

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Comparison
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Comparison
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Agenda

• Introduction
• What is IM system?
• Presence awareness
• Jabber
• What is Jabber?
• Architecture
• Protocol
• Client/Server interaction
• Other popular IM system
• Features
• Comparison
• Conclusion

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Conclusion

• Advantage and Disadvantage of IM
• Key success factor
• Combining instant message delivery and
  presence information
• Existing Problems
• Security Eavesdropping, Account Hijacking,
  Password protection, Data Access
• and Modification
• Efficiency Disturb and waste time during
  work
• The attractive characteristic of Jabber is its
  open source protocol
• Market leaders have more attractive and
  practical functionalities
• Free, open, public, scalable and easily
  understandable
• IM goes into Mobile!
• Combine with wireless network, mobile phone
  and IP technology

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• Thanks for your attention!