QoS Queueing, Policing, and Shaping Compared
LLQ, CBWFQ, policing, and shaping each do something different. The three primitives, when to use which, hierarchical shaping for sub-rate WAN handoffs, and the production patterns.
Archive
Latest posts — page 41
QoS Classification, Marking, and Trust Boundaries
Classification and marking at the trust boundary are the foundation of every QoS deployment. The patterns (untrusted access ports, conditional trust for IP phones, explicit MQC marking) and the discipline that makes them work.
Cisco MQC (Modular QoS CLI): The Operator's Walkthrough
The Cisco MQC three-construct model (class-map, policy-map, service-policy) covers every QoS feature on IOS, IOS XE, and IOS XR. The grammar, common actions, hierarchical policies, and verification.
DSCP and IP Precedence Explained Byte by Byte
DSCP is the 6-bit Layer 3 marking that drives modern QoS. The byte format, the standardized PHBs (CS, AF, EF), Cisco's DSCP-to-CoS-to-MPLS-EXP mapping, and trust boundary discipline.
SD-WAN Security and the SASE Convergence
SD-WAN provides encryption and segmentation but creates an inspection gap. SASE fills that gap with cloud-delivered SWG, CASB, FWaaS, ZTNA, and DLP. The 2026 vendor landscape compared.
SD-WAN Deployment Models: Hybrid, Internet-Only, and Cloud On-Ramp
The four SD-WAN branch deployment models compared (hybrid, internet-only, cloud on-ramp, multi-cloud), HQ patterns, and the typical 18-30 month migration from MPLS-only.
Cisco vManage / SD-WAN Manager: The Operator's Walkthrough
Cisco vManage (now SD-WAN Manager) is the management plane of Cisco Catalyst SD-WAN. Templates, policies, dashboards, the REST API, HA model, and the operational realities at scale.
Cisco Catalyst SD-WAN Architecture: vManage, vSmart, vBond, WAN Edge
The four-component Cisco Catalyst SD-WAN (formerly Viptela) architecture: vManage, vSmart, vBond, and WAN Edge. OMP routing protocol, cEdge vs vEdge, fabric bring-up walkthrough.
SD-WAN Architecture: Control, Data, and Management Planes Explained
Every SD-WAN platform shares the same three-plane architecture: management, control, and data. The vendor-specific components (vManage, vSmart, FortiManager, etc.) compared.
SD-WAN vs MPLS: When Each Wins in 2026
SD-WAN and MPLS are not pure substitutes. The technical differences, cost story without the marketing spin, when MPLS still wins, and the hybrid pattern most enterprises end up with.
MP-BGP: Multiprotocol BGP Address Families Explained
MP-BGP (RFC 4760) is what lets a single BGP session carry IPv6, VPNv4, EVPN, and more. The AFI/SAFI model, route distinguishers, and how modern data center fabrics use MP-BGP for everything.
STP vs RSTP: Convergence, Port Roles, and When to Switch
Classic 802.1D STP vs 802.1w RSTP. The convergence differences (30s vs sub-second), the port state and role changes, and the one-command Cisco migration from PVST+ to Rapid PVST+.