Connection management based on Quality of Service (QoS) offers opportunities for better resource allocation in networks providing service classes. "Negotiation" describes the process of cooperatively configuring application and network resources for an application's use. Complex and long-running applications can reduce the inefficiencies of static allocations by splitting resource use into "eras" bounded by renegotiation of QoS parameters. Renegotiation can be driven by either the application or the network in order to best match application and network dynamics. A key element in this process is a translation between differing perspectives on QoS maintained by applications and network service provision. We model translation with an entity called a "broker".