Networking Sdwan Cisco Sdwan 20 15

SLA Threshold Improvements (17.15.1a+)

SLA class threshold evaluation refined for improved accuracy:

• More precise latency/jitter measurement at sub-millisecond granularity
• Reduced false-positive SLA violations on stable transports
• Better alignment between BFD probe measurements and actual application experience
• Particularly impactful for voice and video SLA classes where small measurement errors triggered unnecessary path switches

Action: Review existing SLA class thresholds after upgrading to 17.15. Previously tight thresholds may now behave differently due to improved measurement accuracy. Validate against actual application metrics.

Enhanced AAR (EAAR) Improvements

Building on EAAR introduced in 17.12:

• Improved per-flow rerouting stability -- fewer unnecessary mid-flow reroutes
• Refined sub-second path switching for MPLS/private transports
• Better load balancing distribution across multiple SLA-compliant paths
• Reduced CPU overhead of EAAR processing on WAN Edge

Configuration Groups Maturity

Configuration groups (introduced in 20.12) reach broader feature coverage:

• More feature profiles available (covers majority of use cases that previously required device templates)
• Improved device tagging and group assignment workflows
• Better variable handling across feature profiles
• Migration tool improvements for converting device templates to configuration groups

Recommendation: New deployments on 20.15 should evaluate configuration groups as the primary configuration model. Existing device template deployments can coexist and migrate incrementally.

Additional 20.15 Features

• Improved SD-WAN Manager API performance for large-scale automation
• Enhanced NWPI (Network-Wide Path Insights) trace detail
• Cloud OnRamp for SaaS improvements (additional SaaS app support, faster probe convergence)
• UTD signature update reliability improvements

LTS Lifecycle Considerations

Why Choose 20.15 LTS

• Long-term support: Extended maintenance window with critical bug fixes and security patches
• Stability: LTS releases receive fewer disruptive changes; focus on reliability
• Production-proven: LTS releases are the recommended choice for risk-averse environments
• Compliance: Organizations requiring change-controlled environments benefit from infrequent major updates

20.15 vs 20.18 (Current Standard)

Upgrade Path

• From 20.12 LTS: Direct upgrade supported. Review release notes for behavioral changes.
• To 20.18: Upgrade when 20.18 reaches LTS designation or when specific 20.18 features are required.
• Version alignment: When upgrading controllers to 20.15, upgrade WAN Edge devices to 17.15 in the same maintenance window (controllers can be one version ahead temporarily).

Migration from 20.12 to 20.15

Pre-Upgrade Checklist

1. Backup: Export all configurations from SD-WAN Manager
2. Review release notes: Check for known issues and behavioral changes
3. Verify hardware compatibility: Confirm all WAN Edge platforms support 17.15
4. Review custom iRules/CLI templates: Check for deprecated CLI commands
5. Lab test: Deploy 20.15 in lab and test critical workflows
6. Capacity check: Verify SD-WAN Manager cluster has sufficient disk space for upgrade

Upgrade Procedure

Follow the standard controller upgrade sequence:

1. Upgrade SD-WAN Manager cluster (one node at a time, verify cluster health between nodes)
2. Upgrade vSmart controllers (OMP graceful restart protects data plane)
3. Upgrade vBond orchestrators
4. Upgrade WAN Edge devices in batches (start with non-critical sites)

Post-Upgrade Validation

1. Verify all control connections re-established: show sdwan control connections
2. Verify all BFD sessions up: show sdwan bfd sessions
3. Check OMP route counts match pre-upgrade baseline: show sdwan omp routes | count
4. Validate app-route statistics: show sdwan app-route statistics
5. Monitor for 48-72 hours before declaring upgrade successful
6. Re-validate SLA class behavior (threshold accuracy changes may affect AAR decisions)

Version Boundaries

Features NOT in 20.15 (available in 20.18+):

• Global search across devices, templates, policies, and logs
• Guided Day-0 task flow in SD-WAN Manager
• NWPI automatic security alert tracing
• Wi-Fi 7 profile support on WAN Edge

Features available in 20.15 from earlier releases:

• All 20.12 features (configuration groups, enhanced NWPI, Cloud OnRamp improvements)
• EAAR (from 20.12 / 17.12)
• UTD with TLS decryption
• Cloud OnRamp for SaaS, IaaS, and colocation

Common Pitfalls

1. SLA threshold recalibration -- The improved measurement accuracy in 17.15 means previously stable SLA classes may trigger differently. Test before production upgrade.
2. Configuration group migration timing -- Do not try to convert all device templates to configuration groups during the upgrade. Upgrade first, stabilize, then migrate templates incrementally.
3. Controller-edge version gap -- Ensure all WAN Edge devices are upgraded to 17.15 within the maintenance window. Running 20.15 controllers with 17.12 edges is supported temporarily but not long-term.
4. Cluster upgrade patience -- Do not rush the SD-WAN Manager cluster upgrade. Wait for full cluster convergence between each node upgrade (monitor Elasticsearch and Cassandra health).

Reference Files

• ../references/architecture.md -- Controller roles, OMP, TLOC, BFD, data plane
• ../references/diagnostics.md -- CLI troubleshooting, NWPI, tunnel debugging
• ../references/best-practices.md -- Template design, policy design, upgrade procedures