Results Summary and Analysis

The JVD team validated the reference design of the converged 5G xHaul network and MBH architectures over seamless segment routing with color-mapping pre-slicing capabilities supported by ACX710 and ACX5448 Universal Metro Routers. ACX710 and ACX5448 DUT routers with Junos OS Release 21.2R3 successfully passed the validation test cases with scale and performance parameters observed within anticipated limits.

The validation testing focused on delivering a Seamless MBH solution across BGP-LU stitched domains with ACX710 and ACX5448 in roles supporting 4G/5G Access Node and Pre-Aggregation packet-switched transport CSR-to-SAG, CSR-to-HSR, and HSR-to-SAG.

Contact your Juniper Networks representative for test result reports.

The JVD validation demonstrated a robust solution for 5G xHaul transport infrastructure utilizing Seamless SR and color-aware network pre-slicing concepts. The architecture provides for resilient and agile deployment, spanning multiple IGP domains and autonomous systems with end-to-end flexibility, path management, and traffic steering.

Key results are as follows:

• JVD topology generates reasonable multi-vector scale of L2/L3 connectivity services as compared with mobile network operator (MNO) and metro area network (MAN) operator expectations for real network deployments, while satisfying SLA requirements.
• The scale reference characterizes primary multidimensional KPI’s represented in the validated profile.
• With given network design, the architecture can deliver fast restoration within 50ms for most traffic flows transported over ISIS-SR with TI-LFA.
• Load distribution and optimization knobs were shown to improve service restoration against link/node failures.
• Link events consistently achieve <50ms convergence while node failures were more disruptive than expected, exacerbated by scale and in some rare cases, production limitations.

ACX710 and ACX5448 Universal Metro Routers with Junos OS release 21.2R3 can deliver the solutions outlined herein across intra and interdomain architectures. Both platforms are ideally situated for access roles and ACX5448 Universal Metro Router can be further leveraged in an aggregation HSR role.

Load sharing operations are enabled on all devices for ECMP opportunities across Fronthaul, Midhaul, and Backhaul segments. Several ECMP mechanisms were configured including adjusting IGP metrics, BGP multipath and add-path, and ECMP fast-reroute. Colored underlay slices are available for all supported services. For example, bronze services are load shared across only blue paths and gold services are load shared across only red paths. Contact your Juniper Networks representative for the colored traffic distribution information. Color agnostic services are shown to always select and disperse over best paths. The distribution of traffic flows resulted in significantly reduced impact for most failure scenarios.

Contact your Juniper Networks representative for hash computation and ECMP validation information.

The goal of this JVD is to identify anomalous behaviors which might impact solution design.

The solution resiliency was validated against multiple stress conditions and failure scenarios which include but not limited to:

• Adjacent link failures
• Indirect link failures
• Node failures

Table 1 summarizes some key results for Layer 2/Layer 3 services traffic flows restoration under failure conditions. The color-coded Events column represents the expected network slice that must be impacted by the described failure condition. For all test scenarios, we run nearly 200 traffic flows—with each bundling congruent VPN services and encompassing all VPN types—between each Access Node (CSR) to AG1s (HSR), ANs to SAG and AG1s to SAG. In greater majority of cases, the failure recovery measured <50ms but always the traffic item with the highest impact is recorded.

For example, in Table 1, the event AN2(R0) link disable (R0-R4), a red link is disabled between R0-R4, and the expected impact is to services which are mapped to red or color-agnostic.

Table 2 lists the results that were initially measured with higher failover. It was determined that the convergence delay was ECMP routing table update following the failure and hash algorithm calculating the new paths. By enabling equal-cost-multipath fast reroute protection (ecmp-fastreroute) on the SAG (R16), we were able to refresh ECMP information without waiting for route table update.

There is further delay in scenarios where global repair is triggered rather than managed by Broadcom ASIC with HW FRR. Additionally, BFD FRR is not supported on ACX5448 or ACX710 Universal Metro Router. Adjusting revertive timers can help control service restoration but overall, these results were mostly within expectation.