Patent ID: 9667570
Date: 2017-05-30
CPC Classifications: H04L

Claim:
1. In a network node including an ingress IO card, an egress IO card, and a pair of parallel switch fabric cards, wherein one of the switch fabric cards is designated as a working switch fabric card, and the other one of the switch fabric cards is designated as a protection switch fabric card, a method of forwarding a traffic flow from the ingress IO card to the egress IO card, the method comprising, in the ingress IO card: dividing the traffic flow into a committed information rate (CIR) component and an extra information rate (EIR) component based on connection state based entirely on physical-layer parameters of the traffic flow exclusive of Layer-2 and higher parameters and awareness of associated packet header contents, wherein the CIR component comprises a first portion of the traffic flow within a predetermined minimum bandwidth limit specification, and the EIR component comprises an excess portion of the traffic flow above the predetermined minimum bandwidth limit specification, wherein dividing the traffic flow comprises: under normal operating condition of the node, forwarding the CIR component through the working switch fabric card, and forwarding the EIR component through the protection switch fabric card; upon detection of a failure impacting the working switch fabric card, dropping the EIR component and forwarding the CIR component through the protection switch fabric card.