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Cisco Bug: CSCum26615 - Secure SIP 7942/7962 Phones Unregister when BLF with Call List Enabled

Last Modified

Mar 03, 2018

Products (36)

  • Cisco Unified IP Phone 7900 Series
  • Cisco Unified Wireless IP Phone 7920
  • Cisco Unified IP Phone 7945G
  • Cisco Unified IP Phone 7971G-GE
  • Cisco Unified IP Phone 7962G
  • Cisco Unified IP Phone Expansion Module 7914
  • Cisco Unified IP Phone 9951
  • Cisco Unified IP Phone 7941G
  • Cisco Unified IP Phone 6961
  • Cisco Unified IP Phone 6941
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Known Affected Releases

9.3(1)

Description (partial)

Symptom:
Secure SIP 7942 Phones (Authenticated or Encrypted) will unregister with CUCM when BLF with Call List is enabled.  This behavior is seen in environments where marginal packet loss (1% drop) is observed, and the packet drop originates in the direction of Phone to CUCM across network topology in use.

Behavior observed during this fault is a TCP FIN/ACK sent by the Phone to CUCM after entering into TCP Retransmission phase and exceeding it's TCP window size, at which point the Phone will re-register to CUCM.

Conditions:
1) Phone Configuration - Device Security Profile set to SIP Secure (Authenticated or Encrypted)
2) Enterprise Parameter - BLF For Call List set to Enabled
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Bug Details Include

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  • Status
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