The present invention relates generally to data networking systems and more specifically to a network switching device and a method of configuration thereof.
Due to the proliferation of local area networks (LAN""s), needs have developed for more powerful tools to manage such LAN""s as they increase in complexity and size. Modern data networking systems rely on packet transport networks to interconnect the various network elements. Packet transport networks typically incorporate packet switching devices to route the data packets through the network from a source to a destination.
Please refer now to FIG. 1. FIG. 1 shows a conventional switching device 100. The device 100 comprises a plurality of ingress ports 110(a-l), a plurality of switch elements 120(a-l), and a plurality of egress ports 130(a-l). Also shown are the connections 115, 125 between the ports 110(a-l), 130(a-l) and the switch elements 120(a-l), respectively. In general, the ingress/egress functionality of the device 100 may be implemented via a plurality of line cards and the switching functionality may be implemented via a plurality of switching cards. For example, the ingress/egress ports 110(a-l), 130(a-l) may be packaged on N line cards and the switching elements 120(a-l) may be packaged on M switching cards whereby the line cards and the switching cards are connected by an order of (N*M) interconnects. In a typical line card/switching card configuration, the line cards and switching over cards are coupled to a backplane in a substantially parallel fashion.
It is important in the line card/switching card configuration, that the signals between the line cards and switch cards be as short as possible and have a minimum crossover of the electrical coupling. FIG. 1A shows a front view of one conventional design where line-cards/switching-cards are interconnected through a backplane. Assuming that the interconnections, between line cards and switching cards, depicted in FIG. 1 are required, it is easy to imagine the signal routing requirements on the backplane.
In a large scale, high speed switching device, this is achieved by increasing the number of signal layers on a backplane and selecting proper card and connector orientations. However, there are practical limits to the number of signal layers and signal density that can be implemented on the backplane, given the parallel nature of the cards. This results in a limit on the number of signals and cards that can be interconnected given a particular method.
Accordingly, what is needed is a device and an interconnection scheme that is not limited by the above referenced constraints. The system should be somewhat simple, cost effective and capable of being easily adapted into existing technology. The present invention addresses such a need.
A switching device and a method for the configuration thereof is disclosed. A first aspect of the present invention comprises a switching device. The switching device comprises at least one line card and at least one switching card. The device includes a mid-plane coupled to the at least one line card and the at least one switching card. The at least one line card and the at least one switching card are perpendicular to each other.
A second aspect of the invention comprises a method for configuring a switching device. The method for configuring a switching device comprises providing a mid-plane, and providing at least one switching card and at least one line card on the mid-plane. The at least one switching card and the at least one line card are perpendicular to each other.
Through the use of the present invention, line cards and/or switch cards can be connected to a mid-plane via a plurality of connectors wherein the line cards and switching cards are perpendicular to each other. By utilizing this configuration, the signals from the line card to the switching cards no longer need to cross each other. Additionally, the interconnections are short and can be implemented in a few layers. This results in the use of smaller interconnection boards that contain substantially less layers, thereby reducing the overall production costs, increasing the signal integrity of the back plane and overall reliability of the device.