Field Notice: Cisco CallManager Express Sites May Experience One Way Audio With Cisco Unity Express Auto-Attendant Call Transfers to IP Phones

June 02, 2005

---

Products Affected

• Cisco1700

• Cisco2600XM

• Cisco2691

• Cisco2800

• Cisco3700

• Cisco3800

Problem Description

PSTN users calling into Auto-Attendant (AA) on Cisco Unity Express (CUE) and having their call transferred to an IP phone may experience one-way audio during the call.

Background

One Way Audio:

The PSTN user calls directly into Auto-Attendant on CUE, then presses '1' to enter extension they wish to reach. The PSTN user then dials the extension of the IP phone they would like to reach. Call setup is completed fine, but results in one way audio. The IP Phone user is able to hear audio from the PSTN user, but the PSTN user cannot hear audio from the IP phone user.

Sniffer traces show that the phone is both sending and receiving RTP packets. A show call active voice brief during the call shows that both the telephony side and IP side are both transmitting and receiving packets. Additional tests done by using the test voice inject-tone towards the PSTN side and listeners were able to hear the injected tone.

Problem Symptoms

PSTN user calls directly into Auto-Attendant on CUE, then presses '1' to enter extension they wish to reach. PSTN user then dials the extension of the IP phone they would like to reach. Call setup is completed fine, but results in one way audio; IP Phone user is able to hear audio from PSTN user, but PSTN user can't hear audio from IP phone user.

To verify that CSCsa83853 is the cause, use the following procedure:

1. To avoid excessive debug messages to console and send debug output to system log only, configure following

   no logging console 
   logging buffered 51200 debugging
   

2. Enable debug hpi all

3. Call into CUE AA from PSTN and have AA transfer call to IP phone

4. Verify one-way audio and disconnect call

5. Enter show log to display debug output

The following output of the debug hpi all shows that the voice packets are being discarded with error msg Protocol Violation when there is one way audio:

*Apr 27 13:30:26.258: //1/F9F92D388002/HPI/[0/0/1:23 (1)]/hpi_receive_message: 
Packet details: 
Packet Id=204 
*Apr 27 13:30:26.258: //1/F9F92D388002/HPI/[0/0/1:23 (1)]/hpi_receive_message: 
Protocol Violation 
Packet details: 
Packet Length=14, Channel Id=1, Packet Id=204 
DPV Violation ID=2, DPV Violation field=0 

Workaround/Solution

The problem exists in Cisco IOS® Software release 12.3(11)T4 and 12.3(11)T5. The problem is fixed in 12.3(11)T6. The problem does not depend upon CUE software version.

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.

DDTS	Remarks
CSCsa83853 (registered customers only)	Cisco Unity Express (CUE) Auto-Attendant one-way audio call. Fixed in 12.3(11)T6.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

• Open a service request on Cisco.com
• By email
• By telephone

Receive Email Notification For New Field Notices

Product Alert Tool - Set up a profile to receive email updates about reliability, safety, network security, and end-of-sale issues for the Cisco products you specify.

---