E-transactions via shopping agents constitute a promising opportunity in the e-markets. It becomes relevant what kind of information and what kind of exchange policies between competing sites can better model the e-market world. There are several steps for building e-business: (i) attracting the customer, (2) knowing how they buy, (iii) making transactions, (iv) perfecting orders, (v) giving effective customer service, (vi) offering customers recourse for problems such as breakage or returns, (vii) providing a rapid conclusion such as electronic payment. In the distributed e-market paradigm, these functions are abstracted via agents representing both contractual parts. In this chapter we will discuss the problem of contract negotiation in e-marketplaces. We succinctly present related topics commonly used to implement negotiation in e-markets, and analyze the bargaining process within e-markets. A study-case of a marketplace for e-services will be presented and analyzed.

INTRODUCTION

The purpose of this chapter is to provide an introduction to and overview of the Quality of Service (QoS) protocols, which is now available or under development in order to provide services for the real-time multimedia applications in the Internet Protocol (IP) based networks. Standard data delivery service provided by IP-based networks is characterized as "best effort". Best-effort service scales well, as evidenced by the today's Internet to support its phenomenal growth. As more hosts are connected, network service demands eventually exceed capacity, but service is not denied. Instead, it degrades gracefully. Although the resulting variability in delivery delays (jitter)...