[This is preliminary documentation and subject to change.]
To facilitate explanation, the Generic Quality of Service (GQOS) documentation divides the GQOS components into three categories:
This division is purely for the sake of convenience and clarity. Though each of these GQOS components is in some way initiated at the client or end-node, and in pure semantics, is initiated by the application, the impact of the component may be greatest elsewhere.
For an example (which may be clearer once the 802.1p GQOS component is further explained), the 802.1p precedence bits are actually set in the end-node's network stack, and is done so because an application initiated a sequence of GQOS events that eventually triggered the setting of the bits. The cause of this bit-setting, then, could be argued to be the application's initiation of GQOS service (thus application-driven). However, because the effect of setting the priority on 802.1p bits has the greatest impact when the packets associated with this session cross their local segment, 802.1p is included in the Network-Driven GQOS Components category, and not in the Application-Driven GQOS Components category. Despite the fact that no quality of service requests would have been instigated to set the 802.1p bit without the application's invocation of a GQOS component, its explanation is best placed in a discussion of network-driven components. The ripple-effect of 802.1p bit setting, then, is felt greatest in the network.
Although individual components from among the three categories can function independently at times to provide subsets of QOS functionality, GQOS overall is an integrated technology.
The following figure provides a visual representation of the structure of GQOS documentation, and the reasoning behind its structure; certain GQOS components have greatest impact in one of the three categories, and are thus discussed there: