ces can be offered long into the future. On the supplier side, there are now many vendors of network management OSS software offering functionality far beyond what has traditionally been bundled by telecom hardware vendors with their network gear. Telecom hardware vendors have a powerful position after they have made a sale to an operator, and can use this to sell OSS software that is tightly integrated with their hardware. These vendors are also investing heavily in OSS, which they often bundle in sales of networking equip- ment. A vendor who has won a bid for network equipment, and who then also com- petes for the OSS component of the bid can deny essential information about their K. Misra et al. (eds.), OSS for Telecom Networks © Springer-Verlag London Limited 2004 OSS for Telecom Networks network hardware to competing OSS vendors. The result is often that vertically inte- grated network hardware/OSS vendors can shut smaller vendors out of OSS bids, reducing competitiveness in the OSS space and perpetuating a vertically integrated structure in the telecom industry. Such tactics are not good for the telecom industry in the long term, because carriers will often be denied the opportunity to consider seri- ously the product offerings of the specialist, non-vertically integrated OSS vendors. The majority of OSS systems are developed in-house by telecom carriers them- selves. However, the "buy or build" debate has gained prominence. This is the ques- tion whether OSS software should be bought "off-the-shelf" or developed ("built") in-house. Carriers are beginning to realise that the expenditure required in develop- ing and maintaining an OSS in-house is in the medium-to-long term far greater than the cost of buying an OSS from a specialist vendor. This is especially so because the requirements of OSS today are far more sophisticated than in the past. It is a drain on resources for a telecom carrier to develop and maintain an OSS in-house because a telecom operator is not primarily a software development firm. Of co