GSNOC
Detection Engine

SIPMON

SIP signaling failures precede call quality problems. SIPMON runs eight detectors against SIP signaling data to catch carrier degradation, security threats, and registration health issues before they impact calls.

The SIP Signaling Problem

SIP failures cascade. A rising 503 rate indicates carrier capacity issues. Authentication failures may indicate security threats. Registration failures affect all calls to a carrier. By the time call quality metrics degrade, the signaling problem has already been active for minutes.

  • SIP 5xx error rates rising before call quality metrics show any degradation — early warning missed entirely
  • Security threats embedded in unusual SIP response patterns that only become visible through statistical analysis
  • Carrier registration failures silently taking a carrier offline without triggering call-quality-based alerts
  • Retransmission storms consuming SIP processing capacity and degrading responsiveness for legitimate signaling

How SIPMON Works

Eight detectors plus a meta-analysis layer cover the full range of SIP signaling health indicators.

Response Code Distribution

Tracks the distribution of SIP response codes per carrier. Abnormal shifts in 4xx, 5xx, or 6xx rates signal carrier-side issues before call quality degrades.

Timeout Detection

Monitors SIP transaction timeouts per carrier. Rising timeouts indicate carrier responsiveness problems that will shortly manifest as call failures.

Retransmission Analysis

Tracks SIP retransmission rates. Elevated retransmissions indicate packet loss or responsiveness issues on the SIP signaling path.

Carrier Degradation

Correlates multiple SIP signals to produce a per-carrier SIP health score that summarizes the overall signaling relationship quality.

Error Burst Detection

Identifies sudden bursts of SIP errors that indicate acute carrier issues distinct from gradual degradation patterns.

Authentication Failures

Monitors SIP 401/407 authentication failure rates. Elevated rates may indicate credential issues, carrier misconfigurations, or brute-force authentication attacks.

Registration Health

Tracks SIP REGISTER success rates for carriers that use registration-based connectivity. Failed registrations are detected and alerted immediately.

Meta-Analysis

A meta-analysis layer correlates outputs from all eight detectors to produce a single overall SIP health score per carrier, reducing alert noise from correlated signals.

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Screenshot: SIPMON screenshot

Why GSNOC SIPMON Is Different

  • Eight detectors plus meta-analysis provides comprehensive SIP health coverage with correlated alerting rather than eight independent alert streams
  • Per-carrier baselines for response code distributions distinguish carrier-specific normal patterns from genuine anomalies
  • Retransmission monitoring catches a SIP health signal that most monitoring systems ignore entirely

Key Metrics

Response Codes

Distribution of SIP response codes per carrier — abnormal distributions flag carrier-side issues

Timeout Rate

Percentage of SIP transactions that time out without a response from the carrier

Retransmission Rate

Rate of SIP message retransmissions indicating signaling path reliability issues

Error Bursts

Count of sudden error rate spikes indicating acute carrier SIP failures

Overall Health (0–100)

Meta-analysis composite SIP health score combining all eight detector outputs per carrier

Related Detection Engines

See it in action

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