Products
There are several QoS Solutions available in the market place that can be applied to different Network Segments and Systems. Network QoS capable switches, such as those offered by Extreme Networks, Foundry, Cisco, and others provide multiple services, switching, and routing along with QoS and QoS rules capability. These are vendor-specific solutions that require significant knowledge of Network Management and specific understanding of the switch vendor's Command Line Interface or Simple Network Management Protocol (SNMP) Management Information Base (MIB) definition for QoS provisioning, but provides a better solution in the long run. If however, a fast and simple solution is required, the software based QoS solution can be a worthwhile alternative. If existing routers are not QoS capable, upgrading routers in existing infrastructures requires a significant investment of time and effort. Products that can be installed next to routers, such as Allot and Packeteer, provide hardware solutions that provide QoS and limited policy capabilities on a few devices. Load balancers simply make an estimate of the response times of servers among a server farm but does not incorporate QoS in concise manner.
The main limitation of these products are that the server load is sometimes the bottleneck, with the network being uncongested and impacting the effectiveness of differentiated services. Solaris BM 1.6 software and the Sun MC 3.0 software solution exposes a set of API's where the server load can be monitored and dynamic reconfiguration is possible on both the Server and Network Resource. Section , "Appendix A" provides some code skeletons that show how such a solution can be implemented using Sun MC 3.0 software and the Solaris BM 1.6 software API's.