Expert Reference Series of White Papers. Troubleshooting Signaling with Traces in Cisco Unified Communications Manager

Transcription

1 Expert Reference Series of White Papers Troubleshooting Signaling with Traces in Cisco Unified Communications Manager COURSES

2 Troubleshooting Signaling with Traces in Cisco UC Manager Chris Olsen; Global Knowledge Cisco, Microsoft and VMware Trainer, Author and Independent IT Consultant Introduction For those familiar with Cisco IOS-based devices, the real time troubleshooting feature is an IOS command called debug. A comparable tool in Cisco Unified Communications Manager (CUCM) is called trace. The main difference is that CUCM can store traces on server storage for quite some time, whereas IOS devices are not designed to be storage devices, and IOS debug is only in real-time, or redirected to another storage media. Also, just like the quantity of different debug commands are quite immense on a router, the same holds true with trace on CUCM. There are a lot of different CUCM traces that can exist. This white paper is intended to enlighten you on the powerful troubleshooting capabilities of trace in CUCM. This white paper provides an introduction to troubleshooting Cisco telephony utilizing the CUCM tracing feature. The steps included here are based on CUCM v8.x, although the procedure will be very similar if you are running version 5.x, 6.x or 7.x of CUCM. This paper is also written for direct application so you can connect directly into your CUCM and follow step by step. Initial Setup After logging in to CUCM navigate in the upper right side of your screen to Cisco Unified Serviceability. Press Go. Navigate to Trace > Configuration. Select your Server, and select CM Services. (While outside the scope of this white paper, you ll see other options that exist for traces.) Press Go then select the service Cisco CallManager (Active) and press Go again. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 2

3 Note the many items that can be enabled. For the purpose of this white paper, enable at least the following, (you can enable more if you like, but these will get you started on some good basic trace analysis): Enable SIP Call Processing Trace Enable Media Resource Manager Trace Enable All Phone Device Trace Enable H.225 and gatekeeper Trace If you are in a lab environment, select the Debug Trace Level of Detailed then press Save. Be cautious with the Detailed debug level in a production environment as the files will grow quickly. If you are in a production environment with lots of telephony calls occurring, you can skip directly to the next step on initiating traces. If you are performing these steps in a CUCM lab environment, try some of these basic actions to generate some trace content: 1. Make a call from one IP phone to another. Try with a SIP phone 2. Make a call from an outside PSTN phone to an IP phone Copyright 2011 Global Knowledge Training LLC. All rights reserved. 3

4 3. Make a call from an IP phone to an outside PSTN phone 4. Set up a conference call 5. Call from one CUCM cluster to another over an Intercluster trunk (H.323) You can hang up shortly after each call is completed as tracing is focused on the signaling of setting up and tearing down a call. After the telephony events have completed, then you can capture the trace files as follows from the RTMT tool. Real Time Monitoring Tool (RTMT) The main tool for collecting traces in CUCM is the Real Time Monitoring Tool (RTMT). This can be installed from CUCM as a free plugin onto your computer as follows: Navigate in your CUCM to Cisco Unified CM Administration. Go to Application > Plugins. Press Find. Look down the list of plugins until you see Cisco Unified Real-Time Monitoring Tool. For your Linux or Windows OS that you are running on your computer, click Download on the left column. Click Run, and follow the steps of the installation. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 4

5 After the installation is complete, start the tool by logging into your CUCM. To initiate a trace, on the left side of RTMT, click on System, then Trace & Log Central. Double click on Collect Files. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 5

6 Check the All Servers box for Cisco CallManager and if you want to trace media for conferencing, then select Cisco IP Voice Media Streaming App. Press Next. Don t check the box for Select all Services on all Servers and don t select other items. Press Next again. Change the Download File Directory to a familiar location on your computer. Select the Relative Range within the timeframe of the phone event. Recent versions of CUCM now default to compress the trace files in a.gz format. Be sure to check Uncompress Log Files, or you will need to download a tool to decompress these files with a program such as BitZipper. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 6

7 Press Finish. Watch on the bottom right on of the RTMT tool to see the spinning circle progress meter. Under the location you choose to save the trace files from RTMT on your computer hard drive, navigate to yourdirectoryname > yourservername > yourdate > cm > trace > ccm > sdi. Note the time and date of the files. Triple Combo Tool While you can open the files and examine their content with Wordpad, finding specific events in a trace file in a production environment often looks like a needle in a hay stack search. It s much easier to use the Triple Combo Parsing tool an excellent free parsing tool for analyzing trace files. You can get this tool from Cisco TAC, or download free from here: With both the trace files in the directory and the Triple Combo tool visible on your desktop, drag and drop the trace file in question (ccm txt) into the open pane on top of the Triple Combo tool. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 7

8 Press Apply on the bottom right of the tool after you select the following different options and then observe the parsed results in the lower left side of Triple Combo. Select one or several of the buttons below CCM Trace as follows: 1. Q.931/H.225. Since these are both protocols from the International Telecommunication Union (ITU.ORG), it is no surprise that the outputs of these displays are very similar, which is why they are grouped together in the Triple Combo tool. However, telephony actions that use these signals are different. Q.931 is the signaling for ISDN on the D channel for call setup and teardown, which shows caller ID and called numbers for ISDN PRI calls. H.225 is the call setup and teardown protocol for the larger umbrella protocol H.323. H.225 would appear for calls thru an Inter-Cluster Trunk (ICT) or an H.323 gateway to or from the CUCM cluster. 2. MGCP. Media Gateway Control Protocol can be used in CUCM for signaling between CUCM and a Cisco ISR gateway. While MGCP is an internet standard, MGCP is only used from CUCM to a Cisco gateway. Note that Triple Combo will show many MGCP keepalives between CUCM and the gateway. These keepalives are normal, but don t say much else. 3. SCCP. Skinny has been the traditional Cisco IP phone client server signaling protocol for all events on Cisco Phones. Note that if you ve already migrated your Cisco IP phones to a firmware version that supports SIP, Copyright 2011 Global Knowledge Training LLC. All rights reserved. 8

9 then you will not see any SCCP messages. However SCCP remains the only protocol that CUCM supports between CUCM and an ISR to control DSP resources. 4. H.245. This protocol is for capabilities exchange during an H.323 call. H.245 will show negotiations for elements such as voice, video, codec selection and conferencing. SCCP, SIP or MGCP will not generate H.245 traffic, only an H.323 call will. 5. SIP. Session Initiation Protocol is an Internet standard and is rapidly becoming the signaling protocol of choice in the industry, and Cisco continues to add SIP support. You can see SIP traffic if you make a call to or from a SIP phone, make a call thru a SIP trunk, use presence from a CUCM SIP trunk to Cisco Unified Presence Server (CUPS), or for voice mail if SIP is configured for integration. CUCM can be integrated with Microsoft s telephony products OCS 2007, OCS 2007 R2 or Lync 2010 with a Microsoft Mediation Server. SIP is the only option for this integration as it is the only signaling protocol that Microsoft currently supports. Other 3rd party SIP phones can also register to CUCM, and calling to or from them will generated SIP traces. 6. DA. This is not a separate protocol but simply shows the digit analysis which displays the Calling or ANI numbers called from and the Called or DNIS numbers dialed to. DA will display the phone numbers for all signaling protocols used. Note that for one call multiple different protocols could be used, for instance: 1. A CUCM IP phone calls an outside PSTN call. This will show SIP or SCCP for the IP phone, and then MGCP or H.323 for the gateway, and Q.391 for ISDN. You will also see DA for the digits dialed. 2. A SCCP phone calls a SIP phone in the same CUCM cluster. You will see SCCP and SIP, as well as DA for the dialed digits. While gateway debug analysis is beyond the scope of this paper, note the IOS Trace option in the middle of Triple Combo. You can turn on voice related debug commands such as debug isdn q931 on a Cisco IOS gateway known as an Integrated Services Router (ISR). Then cut and paste the debug output from the router console into a Notepad file, and then drag and drop the entire saved Notepad file into the top of Triple Combo. You can analyze its content as well. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 9

10 An effective approach to troubleshooting is to educate yourself to the very specifics that traces will show when everything is functioning normally in your environment. Spend some time and really study the details you see. Then, when something goes wrong, perform these steps for tracing again, and you will be better educated to identify the differences of the trace outputs, which will better enable you to identify the origin of the problem. Conclusion There is far more to troubleshooting all possible telephony events on CUCM than meets the eye. However, by practicing these basic skills of creating, parsing and studying trace files with Triple Combo, you ll be well on your way to become an excellent CUCM Unified Communications troubleshooter. Learn More Learn more about how you can improve productivity, enhance efficiency, and sharpen your competitive edge. Check out the following Global Knowledge course: TVOICE - Troubleshooting UC Systems v8.0 For more information or to register, visit or call COURSES ( ) to speak with a sales representative. Our courses and enhanced, hands-on labs and exercises offer practical skills and tips that you can immediately put to use. Our expert instructors draw upon their experiences to help you understand key concepts and how to apply them to your specific work situation. Choose from our more than 1,200 courses, delivered through Classrooms, e-learning, and On-site sessions, to meet your IT and business training needs. About the Author Chris Olsen has been an IT trainer since 1993 and an independent consultant and technical writer since He has taught over 60 different IT and telephony classes to over 15,000 students. He is a technical editor for Global Knowledge s lab manuals and he has published two books with Cisco Press, CIPT part 2 and CCNA Voice Flash Cards. He is an author and technical editor on both Microsoft OCS 2007 and 2007 R2 certification exams. He is a technical author for Cisco certified Courses. He is also currently working with his publisher, CiscoPress, finalizing CIPT part 2 v8. Copyright 2011 Global Knowledge Training LLC. All rights reserved. 10