Core Issue
When a call is placed from a Computer Telephony Integration (CTI) application, such as WebDialer, the dial tone sounds on the phone that makes the call for 15 seconds before the call goes is placed. This issue occurs on these Cisco CallManager versions:
This happens when the dialed number overlaps with another number. For example, the number 10011 is also a potential match for the dialed number 1001.
Resolution
This issue is documented in Cisco bug ID CSCsf20938. There is no workaround available for this issue.
In order to resolve this issue, upgrade or install the Service Release (SR) and Engineering Special (ES) software versions listed in the First Fixed-in Version 4.3(0.1), 4.3(0.4), 4.1(3)SR04, 4.2(1)ES30, 4.1(3)ES81, 4.2(3)ES05, 5.1(0.9921.027), 6.0(0.9901.032), 5.0(4.2116.001), 5.1(1.1000.007), 4.1(3)ES89.1, 5.1(1.2000.002.