Preview Tool

Cisco Bug: CSCvu83070 - CUCM sends ACK on ephemeral port in response to 491

Last Modified

Oct 12, 2020

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases


Description (partial)

Due to a race condition cucm receives sip 491 message. At this point cucm responds with ACK to an ephemeral port (instead of default port 5060)

Cucm and remote endpoint sends reInvite to each other at the same time. That triggers remote endpoint to send sip 491 message to cucm.
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.