Table of Contents
Note Firmware release 8.1(1b) is designed and tested to interoperate with Cisco call control, most notably Cisco Unified Communications Manager releases 6.0 and 5.1. Although SIP firmware is IETF RFC 3261 compliant, it is not supported by Cisco TAC or Engineering for use with non-Cisco call control systems.
Refer to the Cisco Unified Communications Manager Business Edition Documentation Guide and other publications that are specific to your Cisco Unified Communications Manager release. Navigate from the following URL:
Shared lines are not supported on Cisco Unified SIP Phone 3911. The Cisco Unified SIP Phone 3911 Administration Guide for Cisco Unified Communications Manager 6.0 and 5.1 and Cisco Unified SIP Phone 3911 Phone Guide for Cisco Unified Communications Manager 6.0 and 5.1 erroneously state that shared lines are supported.
Cisco Unified SIP Phone 3911 requires the use of gateways with media termination point (MTP) transcoders that support RFC 2833, such as the Cisco 3825 Router in order to support dual tone multi-frequency (DTMF). You can configure the system to support DTMF by either configuring the MTP on a transcoding device that supports RFC 2833 or by checking the Require DTMF Reception check box for each registered Cisco Unified SIP Phone 3911 in Cisco Unified Communications Manager Administration, Phone Administration window.
Anything that degrades network performance can affect Cisco IP Phone voice and video quality, and in some cases, can cause a call to drop. Sources of network degradation can include, but are not limited to, the following activities:
- Administrative tasks, such as an internal port scan or security scan
- Attacks that occur on your network, such as a Denial of Service attack
Step 1 To access the Bug Toolkit, go to http://tools.cisco.com/Support/BugToolKit/action.do?hdnAction=searchBugs
For information on obtaining documentation, obtaining support, providing documentation feedback, security guidelines, and also recommended aliases and general Cisco documents, see the monthly What’s New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:
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Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.