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Application Configuration Access Protocol . Praveen S Thangavelu Nov-12-2003 Advisor: Dr Chung-E-Wang Department of Computer Science, CSUS. Motivation and Agenda . Opportunity to study, design and implement a real life internet protocol Solution to client mobility
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Application Configuration Access Protocol Praveen S Thangavelu Nov-12-2003 Advisor: Dr Chung-E-Wang Department of Computer Science, CSUS
Motivation and Agenda • Opportunity to study, design and implement a real life internet protocol • Solution to client mobility • Understanding RFC specifications • Agenda • Overview • Protocol Framework • ACAP Commands • Design Issues – Methodology, scope & clients • Major functionality • Problems • Results and Future enhancements
Overview • Companion protocol to IMAP • IMAP vs. ACAP • History – IMSP and ACAP • Directory Service?? • Application of ACAP and Example • ACAP Usage for Mobile User • Example Clients • EUDORA – ACAP enabled
Data Model and Design Goals • ACAP Data Model • Datasets, entries and attributes • Tree of entries • Rules with which clients access datasets are specified in dataset classes • Pre-defined attributes • Design Goals • Access Configuration/Preferences remotely • Emphasis on client simplicity • Easily manageable – Dataset Inheritance • Clients with intermittent access- slow clients – modtime attribute • Operated well with Large clients
Protocol Framework • Link Level • Assumes reliable data stream (TCP/Port 674) • Client Server connection • Text based line oriented protocol • Commands and responses • Client command • Server data • Server completion results • Tagged response; command continuation request • Operational Considerations • Data transferred comply with underlying transport window size • Multiple commands
Init Connection/Server greeting Non-authenticated Authenticated Logout and close connection Server States • Connection • ACAP greeting • Rejected Connection • Bye Greeting • Successful Authenticate • Logout • Logout command • Server shutdown • Connection closed
Protocol Elements • Datasets • Entries, attributes • Response code • OK, BAD, NO • Access Control Lists • Namespaces • Functionality • Communication • Dataset definition • Parsing system
Implementation Issues • Communication Subsystem • Multiple clients • In memory representation of data • ACAP Command Parsing • Some Server Response codes – Modified • Datasets • CREATE, READ, STORE • Compatibility with real time mail clients • Other mail clients – pine
Some Sample Results • Client: <establishes connection> • Server: * ACAP (IMPLEMENTATION "Plugged In ACAP Server v1.03") (CONTEXTLIMIT "150") (SASL "CRAM-MD5" "KERBEROS_V4") • Client: GH45 STORE ("/addressbook/user/praveen" • "Contact.Name" "Praveen" "Contact.Email" • "praveen@ecs.csus.com") • Server: GH45 OK "STORE completed" • Client: GH46 LOGOUT • Server: * BYE "See ya later" • Server: GH46 OK "LOGOUT completed“ • Planning to store configuration Information for Pine or ELM
Future Enhancements • Server Replication/ Mirroring • Extending per user data to group of users • Scope Extension • Complex Search Queries • Authorization using ACL • Include contexts per session • Extension to Web based clients like squirrel mail