Competitive Contract Net Protocol agents.felk.cvut.cz/c-cnp

1. Competitive Contract Net Protocol http://agents.felk.cvut.cz/c-cnp Jiří Vokřínek, Jiří Bíba, Jiří Hodík, Jaromír Vybíhal, Michal Pěchouček {vokrinek,biba,hodik,vybihj1,pechouc}@labe.felk.cvut.cz Gerstner Laboratory, Department of Cybernetics Faculty of Electrical Engineering Czech Technical University in Prague Czech Republic 24thJanuary 2007 Jiří Bíba SOFSEM 2007 Harrachov, CR

2. Outline... Motto:By concluding commitments the game does not end, but rather starts! Negotiation protocols for real-world competitive domains should allow for the natural behaviour of the involved parties, enable flexibility of cooperation, and take into account whole life-cycle of negotiated commitments with respect to their duration, eventual evolution and termination. • Agent Environments (cooperation, commitments, flexibility) • Interaction Protocols (limitations) • Competitive Contract Net Protocol (C-CNP) • Performatives in C-CNP (semantics) • Conclusion • Discussion

3. Agent Environments • Collaborative Multi-Agent Environments (Intra-Enterprise Level) • definition:agents’ primary motivation is maximization of their common social welfare • cooperative problem solving based on social commitments (W.&J.) • a-prior willingness to cooperation, common rationality & joint intentions (commitments kept, reconfigured or commonly dropped) • Competitive Multi-Agent Environments (Extra-Enterprise Level) • definition:agents’ primary motivation is maximization of their individual utilities (self-interested agents) • agents are willing to take on obligations only if rewarded, individual rationality & intentions may result in dropping the commitments • full commitments vs. levelled commitments (decommitments) (S.&L.) • explicit metrics of utility desirable – motivates agents to: • (i) enter commitments (rewards) • (ii) comply with commitments (penalties)

4. Interaction Protocols • One-to-one/One-to-many/Many-to-many • Monotonic Concession Protocol • n-agent extension of Monotonic Concession Protocol • Extended CNP and derived protocols • FIPA Query/Request Interaction Protocol • FIPA Dutch/English Auction Interaction Protocol • FIPA Contract Net/Iterated Contract NetInteraction Protocol • Limitations of commonly used protocols • usually designed for collaborative environments (although sometimes used inappropriately in competitive environments) • usually do not cover all the contract/commitment life-cycle (conclusion, eventual evolution, termination) • lack of (standardized) interaction protocols for deployment in real-world competitive environments

5. Competitive Contract Net Protocol • FIPA-like, multi-phase, multi-round interaction protocol hybrid state/sequence diagram of C-CNP:

6. Competitive Contract Net Protocol Contract Conclusion Phase Contract Termination Phase Optional Decommitment Phase

7. Competitive Contract Net Protocol Contract Conclusion Phase Contract Termination Phase Optional Decommitment Phase

8. Competitive Contract Net Protocol Contract Conclusion Phase Contract Termination Phase Optional Decommitment Phase

9. Competitive Contract Net Protocol Contract Conclusion Phase Contract Termination Phase Optional Decommitment Phase

10. Competitive Contract Net Protocol CNP Contract Conclusion Phase Contract Termination Phase Optional Decommitment Phase

11. Competitive Contract Net Protocol ICNP Contract Conclusion Phase (revised) CFP Contract Termination Phase Optional Decommitment Phase

12. Performatives in C-CNP • Re-defined FIPA Performatives • less significant re-definition (almost FIPA compliant) • CFP, PROPOSE, ACCEPT_PROPOSAL, REJECT_PROPOSAL • more significant re-definition • AGREE: generalized • REFUSE: generalized • CONFIRM: generalized • INFORM (FAILURE): generalized (specialized) • New Performatives • IMPOSE_PROPOSAL: 3rd-party-info-based contract proposal • COUNTER_PROPOSE: modified proposal by negotiation initiator • DECOMMIT: start of an optional decommitment negotiation • TAKE_BACK: backing off from decommitment negotiation by payer • PROPOSE_PENALTY: penalty proposal by the receiver (victim) • COUNTER_PROPOSE_PENALTY: penalty proposal by the payer

13. Conclusion • Results • interaction protocol C-CNP for flexible cooperation in competitive environments allowing for commitments evolution and contract-conditions-compliance assessment with emphasis on deployment in e-commerce contracting (i.e. complete contract specification expected to be the subject of a multi-attribute negotiation) • implementation of C-CNP in JADE agent platform v3.3, supporting parallel run of multiple C-CNP in one time, multilevel execution and alternative protocol timing mechanism (machine time or externally triggered timer): http://agents.felk.cvut.cz/c-cnp • Future work • extension of the C-CNP protocol for contract re-negotiation (reconfiguration/outsourcing support) • algorithms and iterative approximate acquaintance models for (reconfigurable) contracting allowing for information inaccessibility, limited resources and reputation issues

14. Discussion Thank you for your attention! Acknowledgements: This research work is part-funded by the European Commission’s FP6 programme within the projects European Collaborative Networked Organizations Leadership - ECOLEAD (contract NO. 506958) and Collaborative Process Automation Support Intelligent dynamic Agents in SME clusters - PANDA (contract NO. 027169). The research is also part-funded by the Ministry of Education, Youth and Sports of the Czech Republic grant No. MSM 6840770013. Any opinions expressed in this presentation are those of the author(s)/organisation and do not necessarily reflect the views of the European Community. The Community is not liable for any use that may be made of the information contained herein.