Cisco Cisco IOS Software Release 12.4(4)T

For problems with endpoints, such as phones, see the manufacturer’s troubleshooting guide.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of 
Cisco trademarks, go to this URL:

. Third-party trademarks mentioned are the property of their respective owners. The 

use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any 
examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. 
Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2005, 2016 Cisco Systems, Inc. All rights reserved.

No audio after transitioning 
from secure to unsecure mode

MAC calls and busy trigger should be 1-to-1 on analog endpoints. (The 
symptom is caused whenyou are receiving a second call while in secure 
mode; you do not hear the call waiting tone.)

The V.150.1 (MER or 
Legacy) capabilities are lost 
over the SIP trunk

Ensure that appropriate V.150.1 SDP filtering options are set for the 
trunk. Filtering options are set via the trunks associated SIP Trunk 
Security Profile and the SIP V.150 Outbound Offer SDP filtering 
service parameter.