Calls between CUCM and the Telepresence Server Fail Due to TIP Negotiation Failure

Introduction

This document describes how you can troubleshoot the issue of a call from a Telepresence Server (TPS) to a CTS (Cisco Telepresence System) endpoint that fails with the "TIP negotiation failed" error.

Problem

When a call is made from the TPS to the CTS endpoint, the call fails and the Telepresence Server shows the error "TIP negotiation failed".

The topology is TPS----VCS----CUCM----CTS Endpoint.

The TPS event log shows these messages :

19661 2012/02/07 15:58:33.095 TP_APPLICATION Info Endpoint Landon
 TP Room (1543) has joined conference 7012345 (1013)
19662 2012/02/07 15:58:33.205 CONNECTION Info endpoint 588:
 configuring for TIP mode
19663 2012/02/07 15:58:33.209 RTCP Info Starting TIP/MUX
 negotiation
19664 2012/02/07 15:58:33.225 RTCP Info Starting TIP/MUX
 negotiation
19665 2012/02/07 15:58:34.253 RTCP Info Far end sent media when
 expecting TIP
 negotiation
19666 2012/02/07 15:58:34.257 TP_APPLICATION Info Endpoint Landon
 TP Room (1543) has 
 abandoned TIP/MUX negotiation
19667 2012/02/07 15:58:34.263 CONNECTION Info endpoint 588:
 tearing down call to "4000"
19668 2012/02/07 15:58:34.297 CONNECTION Info endpoint 588:
 sent disconnect notification
 to control
19669 2012/02/07 15:58:34.380 TP_APPLICATION Info Endpoint Landon
 TP Room (1543) has been disconnected because TIP negotiation
 failed

From the Session Initiation Protocol (SIP) logs, observe that the CUCM responds with the IP address of the IP Phone instead of the CTS in the Session Description Protocol (SDP) that comes in from the CallManager (since both the IP Phone and the CTS have the same extension). Also, the video port is 0 in the SDP.

v=0
o=CiscoSystemsCCM-SIP 2000 1 IN IP4 10.99.25.10
s=SIP Call
c=IN IP4 10.155.189.4 // IP address of the IP phone not CTS and since the IP phone
 cannot do TIP , call fails
t=0 0
m=audio 22812 RTP/AVP 9 101
a=rtpmap:9 G722/
a=ptime:20
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
m=video 0 RTP/AVP 97

Solution

Complete these steps:

1. On the CallManager Device page, from the CTS Auto Answer drop-down list select CTS Override - Auto Answer All.

   

2. For the Line Settings, from the Auto Answer drop-down list select Auto Answer Off.

   

It could also be because the speakerphone is enabled on the IP phone, which explains why the phone IP address was returned in the SDP.

In order to verify the solution, navigate to the Product Specific Configuration Layout section of the IP phone on the Call Manager and verify that the Disable Speakerphone check box is checked.

Note: This is not the only reason that Telepresence Interoperability Protocol (TIP) negotiation fails, but is one of the common reasons.