Preview Tool

Cisco Bug: CSCtf02177 - IME Fallbacks fail under load, issue with allocating unique dtmf key

Last Modified

Nov 03, 2012

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases

8.0 8.0(2)

Description (partial)


In an IME configuration where PSTN Fallback capability is enabled; a subset of IME calls may cease to properly fallback to PSTN, even when voice-quality issues are detected by the system.  This will result in call remaining on the IME network, with the subscriber continuing to experience and perceive voice-quality issues.

Internally, the following will be observed on the terminating UCM of the IME call:

In the detailed SDI, multiple instances of:
PstnFallBackD::wait_PstnFallBackInd- Can not allocate a UniqueDtmfKey for this call E164Dn %s for profile %s

In RTMT, occurrences of this alarm:
"Insufficient PSTN Fallback Identifiers"


Issue is triggered by making IME calls (even at relatively low call volume (10-20 active calls))
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.