Preview Tool

Cisco Bug: CSCul12526 - 8945 SIP:phone black screen when received reinvite to downgrade BW

Last Modified

Feb 11, 2014

Products (11)

  • Cisco IP Phone 8800 Series
  • Cisco Unified IP Phone 9951
  • Cisco Unified SIP Phone 3905
  • Cisco Unified IP Phone 6961
  • Cisco Unified IP Phone 6941
  • Cisco Unified IP Phone 8961
  • Cisco Unified IP Phone 8945
  • Cisco Unified IP Phone 8941
  • Cisco Unified IP Phone 9971
  • Cisco Unified IP Phone 6945
View all products in Bug Search Tool Login Required

Known Affected Releases


Description (partial)

8945 SIP:phone black screen when received reinvite to downgrade BW

UCM version:
PhoneA load: SIP 9-4-1-2
Steps to reproduce:
1. register 1 8945 941 phones and 1 8945934 phone
2. connect pagent between Phone (941 load) and switch
3. drop packet on the pagent port connected to switch
add ip ip-destination port-destination 16386 ip-src is phone with 941 load)
drop on
drop one-in 9
4. make a basic call between phone A and B, CUCM bandwidth set to 2M so video call setup, resolution VGA, capture wireshark trace 
you will find during the bandwidth downgrade, 934 phone black screen once 941 phone send reinvite to negotiate the bandwidth.

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.