General Troubleshooting Cisco VCS Unified CM

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Applicable to UC System Release 9.0(1)

Contents

Introduction

This page provides troubleshooting tips for Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server. The Cisco Unified Communications Manager and Cisco TelePresence Video Communication Server are bridged in an enterprise network. This article discusses how to troubleshoot various interoperability issues that arise between call controls and the appropriate steps required to resolve them.

The intended audiences for this article are system administrators and implementers who are planning to troubleshoot Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server. The audience for this article should be familiar with Cisco TelePresence Video Communication Server and Cisco Unified Communications Manager infrastructure. Also, the audience should also have good understanding of SIP and H.323 call flows.

TIP: Use <Use Video, Cisco VCS> as a keyword to search for related test cases in System Test Results System Test Results for IP telephony.

This topic does not contain detailed step-by-step procedures; for detailed information about configuring Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server, refer to the Cisco VCS Unified CM Deployment Guide documentation.

Deployment and Design Overview

The deployment overview illustrates information about the deployment of Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server. Also, it illustrates the configuration of the different endpoints in the deployment.

Figure 1: Cisco VCS Unified CM Configuration

Cisco VCS UCM Deployment.jpg

The purpose of this section is also to list the design elements (the baseline software used) of the Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server.

The baseline software used for studying the troubleshooting methods include Cisco Unified Communications Manager 8.6(1), Cisco TelePresence Video Communication Server X6.1, Cisco TelePresence MCU 4.2, Cisco Unity Connection 8.6, ISR G2 Video Conference Bridge IOS: 15.1.4M, EX/C Series TC5, E Series TE4.0, Cisco TelePresence Codec 500/1000/3000 1.7.4, Cisco TelePresence MXP Series F9.0.2, Polycom HDX 4000 3.0.0.1, Polycom VSX 7000 9.0.6.1, and Sony PCS-1 3.4.2.

Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server configuration for testing is similar to any other Cisco Unified Communications Manager configuration. The testing coverage includes endpoint testing, call flow scenarios, and failover scenarios.

For information on Cisco Unified Communications Manager integrated with Cisco TelePresence Video Communication Server specific deployments and sites where system testing was performed, see Tested Deployments and Site Models for IP telephony at: IPT TIS Modules 9.0(1).

Troubleshooting

This section provides the methods to diagnose and troubleshoot various interoperability issues that arise between call controls and the appropriate steps to resolve them, for Cisco Unified Communications Manager and Cisco VCS bridged in an enterprise network. The information is discussed as different case studies to facilitate easy understanding for the user.

Case Study 1: Cisco Unified Communications Manager-Cisco VCS SIP Trunk Failure

In this scenario, Cisco Unified IP Phone 9971 gets busier than expected and the call does not get connected. The site topology and specifications where the issue occurs is as depicted in the following illustration.

Figure 2: Unified CM-Cisco VCS SIP Trunk Failure

SIP Trunk Failure.jpg

The root cause for the issue is found to be SIP trunk failure. The troubleshooting for the given issue is carried out as follows:

1. Verify if OPTIONS ping is enabled under SIP profile of the SIP Trunk that connects to Cisco VCS.

2. Ensure Zone configuration in Cisco VCS shows Cisco Unified Communications Manager peer status to be Active and Zone Profile is set to Cisco Unified Communications Manager.

3. Check if the trunk is reset or restarted and if there is a network issue while the call is active (Failure Code: UCM sends BYE with cause code 41).

4. Verify SIP OPTIONS ping from Cisco VCS.

Case Study 2: Session Layer Bandwidth Behavior with Cisco Unified Communications Manager 8.5 and Cisco Unified Communications Manager 8.6

The main focus of this section is to troubleshoot Session Layer Bandwidth Behavior issues with Cisco Unified Communications Manager 8.5 and Cisco Unified Communications Manager 8.6. The root cause for the issue is linked to the common bandwidth attributes b=TIAS :< bandwidth-value>, b=AS <application specific>, and b=CT <conference total>.

  • b=TIAS :< bandwidth-value> or the Transport Independent Application Specific Maximum (TIAS) bandwidth modifier has an integer bit-rate value in bits per second. The bandwidth value is the maximum needed by the application (SDP session level) or media stream (SDP media level) without counting IP or other transport layers like TCP or UDP.
  • b=AS <application specific> or the Application Specific maximum bandwidth is indicated by the modifier AS. The interpretation of this attribute is dependent on the application’s notion of maximum bandwidth.
  • b=CT <conference total> or the Conference Total gives a maximum bandwidth that a conference session will use. Its purpose is to decide if this session co-exists with any other sessions.

A comparison of the bandwidth attributes is provided below.

Figure 3: Comparison of Bandwidth Attributes

Bandwidth Attributes.jpg

The site topology and specifications where the issue occurs is as depicted in the following illustration:

Figure 4: Session Layer Bandwidth Unified CM 8.5 and Unified CM 8.6

UCM 85 86 Deployment.jpg

The troubleshooting for the given issue in Cisco Unified Communications Manager 8.5 is carried out as follows:

1. Set Region Bandwidth to 384 Kbps

2. Initial Invite from E20 to Cisco Unified Communications Manager set to 1152 and bandwidth goes in form of AS

3. Audio Bandwidth is set to 64000 Kbps and Video Bandwidth is set to 1152 Kbps

4. SIP/SDF Status is set to 200 OK, with Session Description

5. Check for No AS Parameter in the answer and there should be NO TIAS for Audio m-line

6. Bandwidth Information TIAS = 320000 (384000-64000)

7. The user will experience choppy or blank video on E20 as the channel rate falls to low value

The troubleshooting for the given issue in Unified CM 8.6 is carried out as follows:

1. Set Region Bandwidth to 384 Kbps

2. Initial Invite from E20 to Cisco Unified Communications Manager set to 1152 and bandwidth goes in form of AS

3. Audio Bandwidth is set to 64000 Kbps and Video Bandwidth is set to 1152 Kbps

4. SIP/SDF Status is set to 200 OK, with Session Description

5. Cisco Unified Communications Manager indicates Region Bandwidth (AS=384), TIAS is 64000 for G.711 codec and Bandwidth Information TIAS = 320000 (384000-64000) for video

6. E20 is offered back with AS and E20 adhering to Cisco Unified Communications Manager bandwidth management

7. Channel rate does not fall to a very low bandwidth

Case Study 3: Cisco Unified Communications Manager BFCP Interoperability

In this scenario, the user is unable to view presentation on a Cisco Quick Set C20 configured in a topology involving Cisco Unified Communications Manager. The main focus of this section is to troubleshoot the interoperability of Cisco Unified Communications Manager and Binary Floor Control Protocol to resolve the issue. The site topology and specifications where the issue occurs is as depicted in the following illustration. It also provides details on the logs to collect.


Figure 5: Unified CM BFCP Topology

Unified CM BFCP.jpg


It is essential to understand the Binary Floor Control Protocol Interoperability with Unified Communications Manager to troubleshoot the issue. BFCP is supported on Early Offer (EO) and Delayed Offer (DO) SIP trunks. Cisco Unified Communications Manager never terminates the BFCP protocol. The UDP/BFCP is supported as it is the preferred industry standard. However, TCP/BFCP is unsupported and works only with legacy deployments.

The troubleshooting for the given issue involves debugging the Sniffer Trace. The root cause for the issue is found to be presentation share using BFCP being disabled. Other reasons are found to be server and control exhibiting same behavior, and flow control not negotiating. The troubleshooting is carried out as follows:

1. Set initial Invite from Cisco TelePresence System EX90 to Cisco Unified Communications Manager, where the Cisco TelePresence System EX90 negotiates UDP/BFCP

2. Set invite from Cisco Unified Communications Manager to Cisco VCS, given that there is no UDP/BFCP application line in SDP.

3. Check if BFCP is disabled on SIP Profile. BFCP capabilities on SIP Trunk can be enabled or disabled on the SIP Profile Configuration page.

4. The SIP Profile with BFCP disabled is configured.

5. Check for any configuration on Cisco VCS to enable UDP/BFCP.

6. The Cisco VCS Default Communication Manager Profile sets SIP UDP/BFCP filter to ON. In the ON state, Cisco VCS does TCP/BFCP that is not supported with Unified CM and hence is not the industry preference.

7. Create a custom profile and set the SIP UDP/BFCP filter mode to OFF.

8. Enable "Allow Presentation Sharing using BFCP" in SIP Profile Configuration.

9. Cisco Unified Communications Manager negotiates BFCP to find that Cisco Quick Set C20 is able to view the presentation.

10. For the BFCP security setting in Unified CM, set "Ignore BFCP Application Line Encryption Status When Designing Call Security Status" to True.

11. For BFCP Device and Endpoint support, use Cisco VCS as proxy.

Case Study 4: Cisco TelePresence Native Interoperability with Cisco Unified Communications Manager and Cisco VCS endpoints

The main focus of this section is to troubleshoot Cisco TelePresence Native Interoperability with Cisco Unified Communications Manager and Cisco VCS endpoints. The site topology and specifications where the issue occurs is as depicted in the following illustration.

Figure 6: Cisco TelePresence Native Interoperability Unified CM and Cisco VCS

CTS Native Interop.jpg

For troubleshooting the Cisco TelePresence Native Interoperability with Cisco Unified Communications Manager and Cisco VCS endpoints:

1. Verify Sysop logs to check for Native and Non-native interoperability.

2. Add the tab Legacy to indicate the interoperability statistics in the web interface.

3. Identify Resolution from Cisco TelePresence Server Logs.

4. Analyze Interoperability Summary for calls from Cisco TelePresence Server.

5. Analyze how Cisco TelePresence Server uses the max-fs to choose encoding resolution and understand how bit rate affects the resolution.

6. Analyze Cisco TelePresence Video Quality and Max-br mapping for codec configuration in Cisco Unified Communications Manager. The maximum resolution is found to be 720 pixels.

Case Study 5: Cisco Unified Communications Manager Integration with Cisco TelePresence MCU

The main focus of this section is to troubleshoot Cisco TelePresence Native Interoperability with Cisco Unified Communications Manager and Cisco VCS endpoints. The site topology and specifications where the issue occurs is as depicted in the following illustration.

Figure 7: Cisco TelePresence MCU Conference Overview

MCU Conference Overview.jpg

For troubleshooting the Cisco Unified Communications Manager Integration with Cisco TelePresence MCU:

1. Add Cisco TelePresence MCU to Cisco Unified Communications Manager through Media Resources, by selecting the option Cisco TelePresence MCU in Conference Bridge Type.

2. Verify the Registration Status and HTTP credentials of Cisco TelePresence MCU.

3. Add MCU resource to MRG and then MRGL to access Cisco TelePresence MCU via MRGL.

4. Verify Cisco TelePresence MCU contained MRGL is configured as part of phone MRGL so as to access MRGL from Device Page.

5. On the Cisco TelePresence MCU side configuration, ensure Media Port Registration is changed to Enabled.

6. Verify that incoming calls to unknown conferences or auto attendant is changed to Disconnect Caller.

7. Time to wait when configuring Adhoc conference PIN is set to Never Configure PIN.

To debug Cisco TelePresence MCU registration issues:

1. Verify that Cisco TelePresence MCU address is correct.

2. Verify that the SIP port incoming and outgoing match the configurations on the Cisco TelePresence MCU.

3. Verify that the Cisco TelePresence MCU is online.

4. Verify that the Cisco TelePresence MCU is configured for SIP.

5. Verify the Cisco Unified Communications Manager traces for the OPTIONS ping to the Cisco TelePresence MCU.

Related Documentation

For related information about Cisco Unified Communications Manager on Cisco Unified Computing System (Unified CM on UCS) Express, see Unified Communications Manager Documentation at:

For information on the results obtained from the system testing:

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