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Gateway Protocols

Cisco IOS, Phone, UCM and CUC Packet, and PCM Captures Command Reference

Document ID: 116078

Updated: Jul 24, 2014

Contributed by Edson Pineiro, Cisco TAC Engineer.

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Introduction

This document describes the specific commands required to collect the output from either CallManager servers or Cisco IOS® gateways and phones. Many documents are referenced in the collection of Pulse Code Modulation (PCM) and packet captures from different platforms.

Packet Capture on CallManager, Unity Connection, or CUPS

In order to run the packet capture, complete these steps:

  1. Secure Shell (SSH) to the CallManager, Unity Connection, or Cisco Unified Presence Server (CUPS) for which you would like to run the capture.

  2. Once you are logged in with the platform administrative rights, enter this command:

    utils network capture size all count 1000000 file ciscotacpub


    Note: Press Ctrl-C to stop the trace.



  3. After the packet capture is collected from the Servers Console/SSH Terminal, collect it with the Real-Time Monitoring Tool (RTMT). Log in to the RTMT and choose these options:

    System > Tools > Trace > Trace & Log Central > Collect Files > Check the Packet Capture Logs check box

For further information about Unified CallManager packet captures, refer to Packet Capture on Unified Communications Manager Appliance Model.

Packet Capture on Phones

CallManager Phone

In order to enable the PC port on the phone at the phone's device level configuration in the Unified CallManager configuration interface, complete these steps:

  1. Log in to the CallManager Administration web interface with administrative rights and complete these tasks:

    Choose the Device > Select the phone > PC Port * > Set to Enable > Save > Apply or Reset the phone

  2. Connect a work station to the PC port on the back of the phone and run Wireshark on the work station.

For more information, reference Collecting a packet capture from a Cisco IP Phone.

CME Phone

This command reference is used to enable a PC Port on a CallManager Express registered IP Phone.

  • The parameter in "service phone <parameter>" is case-sensitive.

  • The Communications Manager Express (CME) PC port only works on certain phones. Ensure the phone load is compatible with the CME version prior to testing.

  • If further assistance is needed, a hub can be used to broadcast the packet from the phone port to a PC connected to the hub.

    !
    telephony-services
     service phone pcPort 1
     service phone spanToPCPort 0
     no create cnf
     create cnf
    !
    ephone xx
     reset
    !


  • In certain phone models and phone loads, the parameters should be changed from "service phone pcPort 0" to "service phone pcPort 1".

  • Once the PC port is enabled, connect a work station to the PC port on the back of the phone and run Wireshark captures.

For further details on the service phone global parameter, refer to these documents:

For further details on compatibility, refer to the Cisco Unified CME and Cisco IOS Software Version Compatibility Matrix to ensure your software is compatible with Cisco IOS. 

Packet Capture on Cisco IOS Gateways

Packet Capture with IP Export

  • This does not work well with the first generation Integrated Services Routers (ISRs) (2800 and 3800 Series routers). The first generation ISRs truncate large packets that cause the Real-Time Protocol (RTP) headers to lose details when troubleshooting Audio RTP related issues.
  • Works very well in ISR G2 (2900 and 3900 Series routers).

  • Optional - access list to filter out any un-wanted captures:

    !
     access-list 100 permit ip any any
     access-list 100 permit udp any any
     access-list 100 permit tcp any any
    !
    !
    !
    ip traffic-export profile TACCAPTURE mode capture
      bidirectional
      incoming access-list 100
      outgoing access-list 100
      no length
    !
    interface GigabitEthernet0/0
      ip traffic-export apply TACCAPTURE size 100000000
    !
    !
    enable:
    traffic-export interface <type-number> clear
    traffic-export interface <type-number> start
    traffic-export interface <type-number> stop
    traffic-export interface <type-number> copy
    !


  • The traffic export is collected directly from the buffer into the flash/tftp/ftp. For example:

    !
    traffic-export interface <type-number> copy ftp://<ftp-ip address>/filename.pcap
    !


    OR

    !
    traffic-export interface <type-number> copy flash://filename.pcap
    !


For further details on Cisco IOS packet captures, refer to Router IP Traffic Export Packet Capture Enhancements.

Embedded Packet Capture

  • This command reference captures the interface GigabitEthernet 0/1 bidirectional.

  • The capture buffer name in this scenario is capture-buff and the interface reference is capture-pt.

    !
    MS-2901#monitor capture buffer capture-buff size 4000 max-size 1500 linear
    MS-2901#monitor capture point ip cef capture-pt gigabitEthernet 0/1 both
    MS-2901#monitor capture point associate capture-pt capture-buff
    MS-2901#monitor capture point start all
    MS-2901#monitor capture point stop all
    MS-2901#monitor capture buffer capture-buff export tftp://10.137.8.185/capture.pcap
    !

For further details on the Embedded IOS packet capture, refer to these documents:

PCM Capture on Cisco IOS Gateway

Earlier than Cisco IOS Release 15.2(2)T1

  • This command reference is used to collect PCM captures on Cisco IOS releases earlier than 15.2(2)T1.

  • The destination of the file referenced here is the flash.

  • The PCM captures a specific port specified by the test voice port command.

    !
     voice hpi capture buffer 50000000
     voice hpi capture destination flash:pcm.dat
    !
    !
    test voice port x/x/x pcm-dump caplog 7 duration 255
    !
    !


  • Run the test voice port command from enable mode.

  • Review the output from the show voice call status command to verify which port the call traverses.

Cisco IOS Release 15.2(2)T1 and Later

SIP and H.323 Gateways

  • With regards to the collection of Cisco IOS PCM captures on Cisco IOS Release 15.2(2)T1 and later, the command reference has changed when compared to earlier Cisco IOS versions.

  • Refer to this command cheat sheet to collect a PCM capture on Cisco IOS H.323 and Session Initiation Protocol (SIP) gateways.

    !
    voice pcm capture buffer 200000
    voice pcm capture destination tftp://x.x.x.x/
    !
    dial-peer voice x voip/pots
     pcm-dump caplog fff duration xxx
    !


  • The capture collects the calls that traverse the specified dial-peer.

MGCP Gateways

  • With regards to the collection of Cisco IOS PCM captures on a Cisco IOS Release 15.2(2)T1 and later, the command reference has changed when compared to earlier Cisco IOS versions.

  • The commands are very similar to the SIP and H.323 gateway PCM captures. However, since Media Gateway Control Protocol (MGCP) gateways do not have specified dial-peer (back-haul), enter the test voice port command in order to apply the trigger that specifies the voice port in question.

    !
    voice pcm capture buffer 200000
    voice pcm capture destination tftp://x.x.x.x/
    !

    test voice port x/x/x pcm-dump caplog fff duration xxx
    !


  • You can also review the output from the show voice call status command in order to verify which port the call traverses.

Triggered PCM Capture on Cisco IOS Gateway

  • The triggered Cisco IOS PCM capture is a feature only available in Cisco IOS Release 15.2(2)T1 and later. 

  • This feature, when enabled on a voice gateway, starts a PCM capture when the DTMF key *** (star, star, star) on a Cisco registered phone is pressed. Ensure the phone call from this phone traverses the gateway in question. 

  • The PCM capture stops after the digits ### are entered on the captured phone. 

  • There is an optional duration parameter that can be used to specify a specific capture duration after the triggered PCM capture is started. If this parameter is set to 0, the capture is infinite until stopped.

    !
    voice pcm capture buffer 200000
    voice pcm capture destination tftp://x.x.x.x/
    voice pcm capture on-demand-trigger
    voice pcm capture user-trigger-string *** ### stream 7 duration 0
    !

    press *** on the IP phone to start the capture
    press ### on the IP phone to Stop the capture

Related Information

Updated: Jul 24, 2014
Document ID: 116078