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Industry Solutions and Trends
Live demos of NorthStar SDN WAN Controller at MPLS World Congress 2017
Mar 15, 2017

The MPLS World Congress in Paris takes place next week, so I thought I would say a few words about the live NorthStar demos at our exhibition booth. As you probably know, NorthStar is our SDN controller for the wide area network. It has direct visibility of the live network, and on the basis of network observations and user input, computes the paths of LSPs across the network and instantiates them using the Path Computation Element Protocol (PCEP).


We have recently given NorthStar more visibility of the live network, by streaming analytics to it from the network nodes. This includes interface statistics, LSP statistics and link delay measurements. This information is sent to NorthStar via streaming telemetry (e.g. Junos Telemetry Interface) or syslog or SNMP.  This leads to the following applications:


(i) Visualisation: the analytics information can be viewed on the Northstar GUI. For example, on the network topology in the NorthStar GUI, the links are colour-coded according to the amount of traffic. Also you can drill down and see detailed traffic graphs for any particular link or LSP that you are interested in for the last hour, day, or beyond. The NorthStar GUI screenshot below shows the traffic on a selected LSP, in bits-per-second (bps) and packets-per-second (pps) as a function of time.


LSP traffic (bps and pps) reported by Streaming TelemetryLSP traffic (bps and pps) reported by Streaming Telemetry


(ii) Input into path computation. You can set up an LSP that follows the lowest latency end-to-end path. NorthStar computes the path on the basis of the link delay measurements received from the network.


(iii) Input into capacity planning. Historical traffic volumes can be extrapolated into the future within NorthStar Planner to help predict when network capacity will need to be augmented.


(iv) Automated actions. Suppose the volume of traffic on a link exceeds a pre-defined threshold. NorthStar knows how much traffic is travelling on each LSP that uses the link, so it can automatically move some of the LSPs onto other paths, in order to ease the congestion. Another type of automated action deals with latency: if the latency of an LSP increases by more than a pre-configured amount, NorthStar tries to find an alternative path that has lower latency and moves the LSP accordingly. Up until know, operators have been making these changes manually, which is very labour-intensive.


If you would like to learn more, I will go into more detail about these use-cases during my conference talk on Thursday afternoon.


Also at our exhibition booth, we will have live demos of NorthStar performing path computation and set-up of segment-routed (SPRING) LSPs. In addition to receiving topological information (nodes, links and associated attributes) via IGP peering or BGP-LS as usual, NorthStar also receives adjacency-SID and node-SID information via either of these protocols. NorthStar can compute strict or loose paths based on adjacency-SIDs or node-SIDs, or combinations of these. Similar use-cases to those already supported for RSVP are supported, for example diverse path computation, bandwidth calendaring, maintenance mode, and secondary LSPs. If a segment-routed path requires admission control (i.e. a bandwidth assignment), then the controller plays a crucial role, as with segment-routing there is no mechanism to reserve bandwidth at the network layer. Instead, NorthStar keeps track of how much spare bandwidth is available on a link, given the segment-routed paths that use that link and their associated bandwidth assignments.


In the screenshot below, you can see how to set up a pair of diversely routed segment-routed LSPs on NorthStar. Note that the network map shows the adjacency-SID values learnt by NorthStar for each direction on each link.


Setting up a pair of diversely-routed segment-routed LSPsSetting up a pair of diversely-routed segment-routed LSPs


The paths, and corresponding SID-values are communicated via PCEP to the ingress routers, which then install the corresponding label-stacks in the FIB. There are PCEP extensions for Segmented Routing that enable this. We will also demonstrate the mapping different VPNs to different LSPs via policy. For example, certain VPNs need to be mapped to a low-latency path, while other VPNs are mapped to a lower cost path that has higher latency.


Want to see more of the new NorthStar capabilites? - Come and see our demos in Paris. See you there!