Symptom
There is a difference in BRI interface behavior between older ISRG2 router and ISR4k router, when using busyout monitor.
ISRG2(VIC2-2BRI-NT/TE) behavior
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1. Busyout monitor configured
2. LAN interface shutdown
3. ISDN Layer 2, Layer 1 shuts down due to busyout monitor
4. BRI inbound call arrives
5. DSU ACT turns on for a few seconds, then turns off (expected)
6. ISDN Layer 2, Layer 1 remain in down state (expected)
ISR4K (NIM-4BRI-NT/TE) behavior
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1. Busyout monitor configured
2. LAN interface shutdown
3. ISDN Layer 2, Layer 1 shuts down due to busyout monitor
4. BRI inbound call arrives
5. DSU ACT lamp turns on and stays on (unexpected)
6. ISDN Layer 2, Layer 1 come up (unexpected)
（MULTIPLE_FRAME_ESTABLISHED）
Conditions
- ISR4k BRI
- Using busyout monitor feature
Further Problem Description
No impact found at this time
