Call quality issues: first-hop diagnostics

Published Aug 9, 2024 • Updated May 1, 2026

Overview

Users report “Teams sounds bad” before networking admits congestion. Structured first-hop triage separates client LAN/Wi‑Fi issues from SIP trunk or PSTN problems.

Data to collect

Time, site, wired vs Wi‑Fi, VPN on/off, headset model, caller/callee direction, whether PSTN or Teams-to-Teams.

Fast tests

  • Teams Call Health panel during repro; note round-trip, packet loss, jitter.
  • Path to SBC or SIP proxy: ping is misleading—use pstn health dashboards where available.
  • Wi‑Fi: RSSI, channel utilization, WMM enabled; rogue AP scan if site-wide.

Escalation

If clean on LAN but bad on Wi‑Fi, network owns. If bad site-to-site only, check MPLS/SD-WAN QoS classes for UDP 3478–3481 and RTP ranges.

Ticket hygiene

Attach screenshots of Call Analytics for that Correlation ID; saves repeat captures when vendor loops.

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