NCS540 Good Middle of the Road Box

1-Under certain traffic conditions involving a high packet rate of packets in placed into a high priority QoS queue the the first level cache limit can be exceeded resulting in jitter/frame delay variation that may be unacceptable in certain use cases. In our specific circumstance we had deployed the NCS540 as a router used to aggregate 10 Gbps ports on the CIN network connecting a CBR8 with RPHY nodes. When QoS was configured in alignment with best practices the high rate of frames for RPHY node timing and DEPI/UEPI session maintenance were experiencing unacceptable levels of jitter (5-10ms) resulting in poor throughput for DOCSIS services. Other use cases involving a high PPS rate of packets in a high priority queue might also experience similar issues. 2- Cisco has been expanding support for various MEF performance management capabilities, however at the time I wrote the review those were not supported. They may be at this time. However at the time I wrote the review they were not so it was fair to point that out. 3- The topic of the review, as asked by TrustRadius, was the NCS500 line overall. While the NCS540 and above do indeed have a broad MPLS feature set, at the time the review was written the NCS520 most certainly did not. There was no support for MPLS, and that fact was not entirely clear in the documentation. It was indicated as a roadmap item. If considering the NCS520 please carefully review Cisco's progress in this area if MPLS capabilities are critical requirements. As a side note since the previous review we have encountered additional issues with the IP fast reroute capabilities of the NCS540. Under certain conditions with high numbers of equal cost routes the route table may not be built correctly unless LFA IP-FRR is disabled or IGP metrics are modified to prioritize one path over another. I am unaware of a current fix. Workarounds are to disable LFA or modify metrics. This was noted in multiple scenarios using ISIS as the IGP in conjunction with MPLS LDP. Unknown if the same conditions apply to SR/TI-LFA, SRv6, or OSPF/LDP configurations.