Service sensitive resilient IPoWDM network and method of operation

摘要

A network and method of operating the network, the network comprising a transport layer that includes first and second disjoint but topologically substantially identical subnetworks A and B, each having a plurality of optical switch nodes and/or reconfigurable optical add-drop multiplexer (ROADM) nodes, and a routing layer wherein each router is coupled to at least one node in A and at least one node in B. The network is operable to provide a plurality of classes of services providing corresponding Quality of Service, and the routing layer or routing/transport interface can differentiate between traffic having different classes of service and schedule the traffic based on its service class. In the case either of the subnetworks becomes inoperable, all of the traffic is transferred to the other subnetwork, and the QoS of the classes of service is maintained by scheduling traffic to increase the delay experienced by delay-tolerant traffic.

主权项

1. A network comprising:
a transport layer that includes:
a first subnetwork (A) having a plurality of optical switch nodes and/or reconfigurable optical add-drop multiplexer (ROADM) nodes, anda second subnetwork (B) disjoint from and topologically substantially identical to A; and a routing layer (L3) comprising a plurality of routers, each router communicatively coupled directly and/or through an interface to at least one node in A and at least one node in B; wherein the network is operable to provide first priority network traffic (F traffic) with a first class service having a first Quality of Service (QoS) and second priority network traffic (S traffic) with a second class service having a second QoS lower than the first QoS; and wherein, in normal operation, F traffic does not exceed half of the total instantaneous network traffic and the network is configured to direct all of the F traffic to A and an amount of S traffic to B that is equal to the amount of F traffic and to split any remaining S traffic between A and B; and wherein the routers of the routing layer and/or the interfaces between the routers of the routing layer and the nodes of the transport layer subnetworks A and B coupled thereto, are configured to direct traffic to and/or from a subnetwork of the transport layer based on the traffic's service class and are operable to be aware of the percentage of the network capacity used by F traffic, recognize the class of service of traffic in a packet stream processed by the corresponding router, split the traffic stream between the corresponding router and the WDM layer, by means of TDM or WDM, so that a predetermined percentage of F and S traffic goes to A and a different predetermined percentage of F and S traffic goes to B; receive an alarm in case of an equipment outage in the WDM-layer, and be aware of the state of the WDM-layer in view of the equipment outage; and responsive to the alarm:
divert packets from A to B without interruption of packet delivery service;schedule the F traffic to be delivered in accordance with the F QoS, and schedule the S traffic to share any remaining capacity on B; and responsive to a confirmation that A has been restored, return the traffic pattern to the pre-alarm state.