QoS — EF, LLQ & the Trust Boundary

Best-effort default means voice competes with backups. QoS is the pipeline: classify → mark → queue → drop smartly → shape/police, following DiffServ (IntServ/RSVP never scaled). Marking L2 CoS/802.1p (0–7) on the frame, L3 DSCP (6 bits) in the IP header: voice EF(46), video AF41, data BE(0). Trust boundary: trust the phone, remark everything from […]