US 2003/0169694 A1 · Use of alternate ports in spanning tree configured bridged virtual local area networks

Abstract

An improvement to the logic for the use of communication links in data networks that require loop-free forwarding of data frames provides for the use of links identified as alternate, or unused, by spanning tree protocols. While imposing no constraints on the locations of communicating stations in the network that can use the alternate links and requiring neither additional protocol between network devices nor awareness by all devices that alternate links are to be used, the improvement provides the benefits of multiple spanning trees in common network configurations while requiring protocol to compute only a single spanning tree and the benefit of additional network scaling where a number of trees are computed. The improvement is applicable to the Bridged Local Area Networks and the spanning tree protocols specified in IEEE Standards 802.1D and 802.1Q and their amendments and revisions.

Claims18

Dependent claims

For a network comprising a plurality of communication links connected by a plurality of network devices said network being capable of transmitting frames of data, a network device comprising:

a plurality of ports coupled to communication links in the network;
topology management resources which manage the plurality of ports to select a primary active topology that is loop-free by forwarding, that is transmitting and or receiving, frames through one or more ports in the plurality of ports and not forwarding frames through the zero or more other ports in the plurality of ports;
additional logic that augments the said primary loop-free active topology by classifying frames of data according to a plurality of certain criteria known to the device and forwarding frames meeting one or more criteria through a first port that frames would not be forwarded through if the criteria were not met and not forwarding said frames meeting said criteria through a second port that frames would be forwarded through if said criteria were not met.

For a network capable of transmitting frames of data, said network comprising a plurality of communication links connected by a plurality of network devices executing a spanning tree protocol with other network devices to select multiple loop-free spanning tree active topologies and using a convention to said network devices to allocate each data frame to one and only one active topology on the basis of protocol fields in said data frame, a network device comprising:

a plurality of ports coupled to communication links in the network;
topology management resources which manage the plurality of ports to select the spanning tree active topologies;
additional logic that augments one or more of the active loop-free topologies selected by said spanning tree protocol by further classifying frames of data allocated to the said active topology according to a plurality of certain criteria known to the device;
additional logic for forwarding frames meeting one or more of said criteria through a first port that frames would not be forwarded through if said criteria were not met and not forwarding said frames meeting said criteria through a second port that frames would be forwarded through if said criteria were not met.

1 more element

Dependencies are inferred from the claim text.

Use of alternate ports in spanning tree configured bridged virtual local area networks

Life of this patent

Use of alternate ports in spanning tree configured bridged virtual local area networks

Life of this patent

Abstract

Claims18