Patent ID: 8170038
Filing Date: 2012-05-01
Classification: H04L

Abstract:
1. A method of link-level data communications, the method carried out in a link-level data communications switching apparatus, the switching apparatus comprising modular link-level data communications switches disposed within a modular computer cabinet, the modular computer cabinet also having disposed within it a plurality of modular computer systems; the switching apparatus configured as two layers of link-level data communications switches, a first layer and a second layer, the first layer switches coupled for data communications to data communications networks, the first layer switches also coupled to one another for link-level data communications by inter-switch links, each of the first layer switches also coupled for link-level data communications to each of the second layer switches, each of the second layer switches coupled for link-level data communications to at least one of the modular computer systems so that each of the second layer switches provides data communications connections to the switching apparatus only for service applications in the modular computer system to which a second layer switch is coupled; all the first layer switches and second layer switches stacked by a stacking protocol that shares administrative configuration information among the first layer switches and second layer switches through the inter-switch links and presents all the first layer switches and second layer switches in the switching apparatus to the networks and to the modular computer systems as a single logical switch; the switching apparatus further comprises a plurality of data communications ports, at least two of the ports coupling the switching apparatus to at least two data communications networks, at least two additional ports connected to service applications on at least two of the modular computer systems that carry out transparent, bump-in-the-wire data processing of data communications packets traveling among the networks, each of the service applications associated with a unique, link-level identifier; the switching apparatus further comprises rules governing steering of data communications among the service applications and networks connected to the switching apparatus, each rule comprising an association of an ingress port and a switch egress, wherein the rules include at least one rule that further includes at least one network code that identifies two networks between which data communications packets may travel through the switching apparatus and a direction of travel between the two networks; the switching apparatus further comprises orientation records that associate, for each of the data communications packets received from a source network, a link-level source identifier of the data communications packets and a network code specifying for each of the data communications packets a direction of travel between two networks; the method comprising: receiving, in the switching apparatus through an ingress port from a source network, data communications packets directed to a destination network, each of the data communications packets containing a source network address that identifies a source of the data communication packet in the source network, each of the data communications packets optionally also containing a destination network address that identifies a destination of the data communications packet in the destination network, wherein each of the data communications packets further comprises a link-level source identifier that identifies a link-level source for each of the data communications packets in the source network; and steering by the switching apparatus each of the data communications packets among the applications and through an egress port to the destination network, such steering carried out only in accordance with the rules, without using the link-level identifier of any service application, steering none of the data communications packets through any of the inter-switch links among the first layer switches, including: