| 摘要 |
A network can be considered to comprise multiple layers 202,204. Example layers could be IP and Ethernet, similar to OSI model layers, or wireless and wired Ethernet could be considered layers or optical traffic and control protocols. Where links between nodes exist in multiple layers the flattened network topology ignores or excludes all but one link (see Fig. 7). Where traffic passes between OSI type layers, for instance optical layer 202 and IP layer 204, the protocol stack may be modelled as a further link 208,210,212,214. Once the network topology has been abstracted data transport services are applied to the single layer model to calculate optimum network routing. The determined routes are then converted back into routing instructions for each network layer. The network topology may model the free capacity of network links. |
