Preview Tool

Cisco Bug: CSCtc93897 - SIP Early media calls which uses PRACK w/sdp fails (Pre-connect calls)

Last Modified

Feb 22, 2014

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases


Description (partial)


SBC -> SIP Trunk -> CUCM -> Trunk/IP_Phone

SIP Early Media calls using PRACK w/SDP fails due to media negotiation timeout as CUCM doesn't forward SDP information in SIP ?ACK response to other call leg.


CUCM 7.1.3. SIP Early media calls using SIP PRACK w/SDP where SDP is exchanged in SIP PRACK. Typical call flow may look like,

Invite                       --------> Incoming SIP Invite
100 Trying                <--------
180 Ringing              <--------

PRACK                      -------->
200 OK                     <--------

183 w/SDP               <--------
PRACK     w/SDP        -------->
200 OK                     <--------
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.