| 摘要 |
An application-aware policy enforcement point (PEP) attaches to the edge of a packet-switched network to manage loading when the network nears or exceeds its capacity due to changes in the network, e.g., component failures or incremental growth. An advanced bandwidth manager (ABM) comprises a session/call admission controller (S/CAC) that monitors and maps ever-changing network topology information gathered from remote listeners about how traffic is being routed through various parts of the network. These reports are harmonized to build a single view of the network topology, and the point-to-point connections are abstracted into path tables. Autonomous PEP' s at the network's edges provide short-term, application-aware controls on their own that are applied to the corresponding network ingress traffic. The S/CAC uses the path tables to calculate whether particular PEP's can admit more traffic, or should they shed sessions/calls to keep service up for the existing application traffic. Long-term controls are periodically downloaded as admission tables from the S/CAC to the PEP's. |
