Dynamic service level negotiation is necessary to flexibly allocate resources according to QoS demands of a host or a domain. We have designed COPS-SLS as a service level negotiation protocol for IP-based networks. In this paper, we analyse a COPS-SLS-based negotiation system from the protocol design and system’s scalability perspectives. This analysis is useful not only to the improvement of the COPS-SLS protocol design but also to the deployment of a service level negotiation system in general.