Refactoring Network Control and Management: A Case for the 4D Architecture
Albert G. Greenberg, Gísli Hjálmtýsson, David A. Maltz, Andy Myers, Jennifer Rexford, Geoffrey G. Xie, Hong Yan, Jibin Zhan, Hui Zhang · 2005
We argue for the refactoring of the IP control plane to support network-wide objectives and control. We put forward a design that refactors functionality into a novel 4D architecture composed of four separate planes: decision, dissemination, discovery and data. All decision-making logic is moved out of routers along with current management plane functions to create a logically centralized decision plane, where network-level objectives and policies are specified and enforced by direct configuration of states on individual network elements. Pulling much of the control state and logic out of the routers enables both simpler protocols, which do not have to embed decision-making logic, and more powerful decision algorithms for implementing sophisticated goals. Remaining on the routers is a wafer-thin class of intrinsically distributed control functions. These support the discovery plane, consisting of elementary functions to discover topology and network state, and the dissemination plane, consisting of elementary functions to distribute explicit instructions to manipulate the data plane forwarding mechanisms.