Root cause analysis / Investigation

chatgpt.com

Reference RCA-711FAFC7340DF342

OpenAI Chat website

Measurement point: Stealth NYC, 32 Avenue of the Americas.

Published investigation. Updates run automatically.

01 / Network path

Network path.

Endpoint measurements / ICMP IPv4

Latency over time.

Successful endpoint RTT recordings from up to one hour before and after the event.

Enter time range

Times use the selected timezone; choices include recorded samples and intervals across the available chart.

Use the recordings table below to view latency values.

Successful RTT recording Event interval

06 Nov 2026 02:35 – 06 Nov 2026 05:19 UTC. Hover or tap to inspect; drag across the chart to zoom. On touchscreens, first choose Select time range. Escape or Reset zoom restores the full range. Missing recordings are gaps; this is not an application availability or packet-loss chart.

Select a recording to explore nearby path observations.

View recorded values
Successful ICMP IPv4 RTT recordings.
Recorded at (UTC)RTT
1.421 ms
1.139 ms
1.160 ms
1.151 ms
1.177 ms
1.149 ms
1.258 ms
1.354 ms
1.186 ms
1.508 ms
1.132 ms
1.389 ms
1.235 ms
1.182 ms
1.137 ms
1.376 ms
1.361 ms
1.165 ms
1.325 ms
1.181 ms
1.374 ms
1.424 ms
1.135 ms
1.420 ms
1.142 ms
1.379 ms
1.138 ms
1.130 ms
1.372 ms
1.364 ms
1.164 ms
1.155 ms
1.449 ms
1.354 ms
1.332 ms
3.866 ms
1.404 ms
1.332 ms
1.424 ms
1.321 ms
1.381 ms
1.201 ms
1.342 ms
1.177 ms
1.347 ms
1.380 ms
1.335 ms
1.342 ms
1.544 ms
1.164 ms
1.156 ms
1.159 ms
1.357 ms
1.356 ms
1.364 ms
1.406 ms
1.337 ms
1.168 ms
1.141 ms
1.140 ms
1.129 ms
1.344 ms
1.333 ms
1.151 ms
1.153 ms
1.123 ms
1.420 ms
1.388 ms
1.353 ms
1.375 ms
1.363 ms
1.124 ms
1.181 ms
1.367 ms
1.339 ms
1.116 ms
1.153 ms
1.234 ms
1.358 ms
1.358 ms
1.355 ms
1.136 ms
1.350 ms
5.097 ms
1.149 ms
1.376 ms
1.196 ms
1.340 ms
1.145 ms
1.188 ms
1.380 ms
1.339 ms
1.357 ms
1.155 ms
1.201 ms
1.189 ms
1.158 ms
1.462 ms
1.362 ms
1.526 ms
1.324 ms
1.120 ms
1.349 ms
1.527 ms
1.161 ms
1.419 ms
1.614 ms
1.145 ms
1.126 ms
1.135 ms
1.158 ms
1.153 ms
1.384 ms
1.375 ms
1.155 ms
1.157 ms
1.317 ms
1.357 ms
1.176 ms
1.388 ms
1.415 ms
1.129 ms
1.311 ms
1.218 ms
1.144 ms
1.366 ms
1.181 ms
1.163 ms
1.354 ms
19.309 ms
16.828 ms
1.438 ms
1.388 ms
1.151 ms
1.144 ms
1.578 ms
1.343 ms
1.346 ms
1.153 ms
1.205 ms
1.256 ms
1.394 ms
1.393 ms
1.366 ms
1.150 ms
16.778 ms
1.106 ms
1.361 ms
1.150 ms
1.321 ms
1.370 ms
1.344 ms
1.460 ms
1.373 ms
1.173 ms
1.147 ms
1.356 ms
1.332 ms
1.156 ms
1.354 ms
1.473 ms
1.172 ms
1.142 ms
1.175 ms
1.520 ms
1.331 ms
1.139 ms
1.362 ms
1.356 ms
1.389 ms
1.154 ms
1.563 ms
1.315 ms
1.141 ms
1.533 ms
1.361 ms
1.957 ms
1.565 ms
15.704 ms
1.304 ms
1.347 ms
1.128 ms
1.397 ms
1.361 ms
1.339 ms
1.399 ms
1.131 ms
1.135 ms
1.136 ms
1.345 ms
1.383 ms
1.401 ms
1.184 ms
1.344 ms
1.360 ms
1.174 ms
1.367 ms
1.131 ms
1.399 ms
1.347 ms
1.126 ms
1.356 ms
1.128 ms
1.429 ms
1.353 ms
1.304 ms
1.627 ms
1.339 ms
1.346 ms
1.130 ms
1.353 ms
1.157 ms
1.380 ms
1.407 ms
1.162 ms
1.383 ms
1.342 ms
1.426 ms
1.160 ms
1.362 ms
1.216 ms
1.341 ms
1.173 ms
1.323 ms
1.395 ms
1.402 ms
1.099 ms
1.378 ms
1.170 ms
1.259 ms
1.356 ms
1.385 ms
1.214 ms
1.195 ms
1.351 ms
1.134 ms
1.812 ms
1.403 ms
1.439 ms
1.359 ms
1.346 ms
1.186 ms
1.475 ms
1.284 ms
1.629 ms
1.112 ms
1.162 ms
1.381 ms
1.140 ms
1.127 ms
1.124 ms
1.326 ms
1.159 ms
1.167 ms
1.130 ms
1.166 ms
1.358 ms
1.152 ms
1.318 ms
1.163 ms
1.405 ms
1.379 ms
1.151 ms
1.370 ms
1.436 ms
1.180 ms
1.161 ms
1.349 ms
1.127 ms
1.131 ms
1.388 ms
1.446 ms
1.132 ms
1.471 ms
1.153 ms
1.188 ms
1.159 ms
1.153 ms
1.136 ms
3.405 ms
1.129 ms
1.116 ms
1.325 ms
1.189 ms
1.512 ms
1.143 ms
1.344 ms
1.179 ms
1.338 ms
1.208 ms
1.233 ms
1.404 ms
1.170 ms
1.172 ms
1.162 ms
1.216 ms
1.449 ms
2.351 ms
1.371 ms
1.362 ms
1.367 ms
1.184 ms
1.161 ms
1.398 ms
1.367 ms
1.322 ms
1.152 ms
1.199 ms
3.823 ms
1.354 ms
1.144 ms
1.138 ms
1.353 ms
1.178 ms
1.147 ms
1.386 ms
1.395 ms
1.159 ms
1.381 ms
1.119 ms
1.353 ms
1.364 ms
1.425 ms
1.194 ms
1.354 ms
1.341 ms
1.346 ms
1.381 ms
1.154 ms
Network path / recorded observations

Network path observations.

17 observations

Choose a measurement type to see the closest of the available sampled observations to the selected chart point. Each probe is separate and may follow a different path.

Before

ICMP traceroute · Recorded address 1

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.113 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.174 msReply RTT AS8002 · Stealth
Before

TCP traceroute / 443 · Recorded address 2

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.152 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.204 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop3.650 msReply RTT AS13335 · Cloudflare
  4. TTL 4 Probe hop1.737 msReply RTT AS13335 · Cloudflare
  5. TTL 5 Probe hop1.893 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Probe hopNo replyNo comparable RTT ASN unavailable
  7. TTL 7 Destination1.451 msReply RTT AS13335 · Cloudflare
Before

ICMP traceroute · Recorded address 2

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.119 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.183 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop1.456 msReply RTT ASN unavailable
Before

TCP traceroute / 443 · Recorded address 2

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.155 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.191 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop8.887 msReply RTT ASN unavailable
  4. TTL 4 Probe hopNo replyNo comparable RTT ASN unavailable
  5. TTL 5 Probe hop1.398 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.042 msReply RTT AS13335 · Cloudflare
Before

TCP traceroute / 443 · Recorded address 2

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.244 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.228 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hopNo replyNo comparable RTT ASN unavailable
  4. TTL 4 Probe hop13.503 msReply RTT AS13335 · Cloudflare
  5. TTL 5 Probe hop1.412 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination0.971 msReply RTT AS13335 · Cloudflare
During

ICMP traceroute · Recorded address 1

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.119 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.190 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop14.482 msReply RTT AS13335 · Cloudflare
During

TCP traceroute / 443 · Recorded address 1

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.149 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.197 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hopNo replyNo comparable RTT ASN unavailable
  4. TTL 4 Probe hopNo replyNo comparable RTT ASN unavailable
  5. TTL 5 Probe hop6.479 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.445 msReply RTT AS13335 · Cloudflare
During

ICMP traceroute · Recorded address 1

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.129 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.184 msReply RTT AS8002 · Stealth
During

TCP traceroute / 443 · Recorded address 1

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.153 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.268 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hopNo replyNo comparable RTT ASN unavailable
  4. TTL 4 Probe hopNo replyNo comparable RTT ASN unavailable
  5. TTL 5 Probe hop1.576 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.256 msReply RTT AS13335 · Cloudflare
During

ICMP traceroute · Recorded address 2

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.164 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.202 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop1.058 msReply RTT AS13335 · Cloudflare
During

TCP traceroute / 443 · Recorded address 1

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.181 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.547 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop0.980 msReply RTT AS13335 · Cloudflare
  4. TTL 4 Probe hop1.797 msReply RTT AS13335 · Cloudflare
  5. TTL 5 Probe hop2.119 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.755 msReply RTT AS13335 · Cloudflare
After

ICMP traceroute · Recorded address 2

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.380 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.190 msReply RTT AS8002 · Stealth
After

TCP traceroute / 443 · Recorded address 1

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.164 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.186 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop8.502 msReply RTT AS13335 · Cloudflare
  4. TTL 4 Probe hopNo replyNo comparable RTT ASN unavailable
  5. TTL 5 Probe hop1.987 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.246 msReply RTT AS13335 · Cloudflare
After

ICMP traceroute · Recorded address 2

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.121 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.198 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop1.634 msReply RTT ASN unavailable
After

TCP traceroute / 443 · Recorded address 1

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.151 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.179 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hopNo replyNo comparable RTT ASN unavailable
  4. TTL 4 Probe hop1.662 msReply RTT AS13335 · Cloudflare
  5. TTL 5 Probe hop1.722 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.009 msReply RTT AS13335 · Cloudflare
After

ICMP traceroute · Recorded address 1

Recorded trace · destination not reached by this trace


to UTC

  1. TTL 1 Probe hop0.118 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.178 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop1.542 msReply RTT AS13335 · Cloudflare
After

TCP traceroute / 443 · Recorded address 2

Recorded trace · destination replied


to UTC

  1. TTL 1 Probe hop0.161 msReply RTT AS8002 · Stealth
  2. TTL 2 Probe hop0.181 msReply RTT AS8002 · Stealth
  3. TTL 3 Probe hop28.646 msReply RTT AS13335 · Cloudflare
  4. TTL 4 Probe hop1.918 msReply RTT AS13335 · Cloudflare
  5. TTL 5 Probe hop1.142 msReply RTT AS13335 · Cloudflare
  6. TTL 6 Destination1.453 msReply RTT AS13335 · Cloudflare

RTT is the round trip to each responding hop, not the delay of the preceding link. TTL order may omit routers and does not prove direct links. A missing reply is not proof of packet loss. ASN labels are dated address associations; they do not establish the forwarding path or the operator at the event time. Up to three recorded traces per method and period are selected across the archive. Where no individual trace is available, a comparison may summarize a window; MTR observations aggregate multiple probes. Address aliases are independent across measurement types.

Same method / same recorded address

Compare the traces.

Compare one selected trace from before the event with one during it. Values are individual replies, not a statistical comparison.

ICMP traceroute · Recorded address 1

Before: UTC · During: UTC

Same destination address and probe method. A matching TTL does not establish the same forwarding path.
TTLBefore RTTDuring RTTResponding address
10.113 msAS8002 · Stealth0.119 msAS8002 · StealthSame responder
20.174 msAS8002 · Stealth0.190 msAS8002 · StealthSame responder
3Not recorded14.482 msAS13335 · CloudflareNot established
ICMP traceroute · Recorded address 2

Before: UTC · During: UTC

Same destination address and probe method. A matching TTL does not establish the same forwarding path.
TTLBefore RTTDuring RTTResponding address
10.119 msAS8002 · Stealth0.164 msAS8002 · StealthSame responder
20.183 msAS8002 · Stealth0.202 msAS8002 · StealthSame responder
31.456 ms1.058 msAS13335 · CloudflareSame responder

RTTs include the return path. Different responders, missing replies and independent probe flows limit what a change can localize. MTR snapshots remain separate in the replay.

Event timeline.

Latency anomaly. Times shown are UTC.

Event opened
UTC
Last event observation
UTC
Recovery observed
UTC

Recorded recovery describes this event, not current reachability.

02 / Assessment

Assessment.

Investigation stateRecovered
Path assessment

Elevated latency observed.

Endpoint round-trip time was elevated during part of the event. The available path observations do not identify where the increase occurred.

What we observed

  • A sustained increase in measured round trip time was observed.
  • Stored traces were compared using matching source and destination addresses.

Recording counts describe collected measurements, not application availability or packet loss. Exact packet paths and the return path remain unverified.

Measurements at a glance.

Baseline RTT1.363 msUsual round trip before the event
Last recorded event RTT1.130 msLast successful event recording
Event p95 RTT1.809 ms95th percentile of successful recordings
Change from baseline-0.232 msLast event RTT compared with the baseline
Successful / expected recordings90 / 90Recorded endpoint samples during the event

RTT is round trip time; p95 describes the upper range of successful recordings. Endpoint measurements differ from individual trace replies and are not an uptime percentage.

Record sources and timestamps
Analysis updated
UTC
Public snapshot published
UTC
Public observation window
– UTC

Event and source timestamps are UTC. The latency chart uses its selected timezone. Page refresh times are separate from measurement timestamps.

03 / Method and limits

Method and limits.

How to interpret the sampled path and its limits

Corroborating the path.

Comparisons use matching destinations before and during the event. ICMP traces use echo probes. TCP/443 traces send SYN probes to port 443 only; they do not complete a TCP handshake or perform a TLS or HTTP exchange.

The Stealth gNMI interface verifies the active route-table choice and maps its primary next hop to the Stealth logical interface, configured attachment and, where applicable, the known LAG member set at each snapshot. Stable Stealth replies, together with mapped interface evidence showing no corresponding errors or sustained capacity pressure, reduce the likelihood of a Stealth forwarding issue. An 80% load warning warrants investigation; it does not prove congestion. Lower interval averages can conceal bursts or queue pressure. Optical readings assess the physical link, not congestion.

What remains unseen.

Probe reply handling can differ from packet forwarding. A slow intermediate reply that disappears at later hops does not locate a forwarding problem. A destination that does not respond to a trace is not thereby shown to be unavailable.

Stealth does not use ECMP in this monitored scope. The route snapshot does not identify which physical LAG member carried a particular independent probe, attest line-card forwarding at that packet instant, prove the exact application packet flow or observe the return path. RTT includes the return path, which may differ. No remote reverse traceroute is available. Tunnels and silent routers may hide parts of the path. Address registration alone does not establish the forwarding operator or responsibility.

References: ICMP reply handling / RFC 1812 · Round trip measurements / RFC 2681 · Full methodology