Downloads |
Table Of Contents
Restrictions for Voice Call Tuning
Information About Voice Call Tuning
How to Verify Voice Call Tuning Functionality
Configuration Examples for Voice Call Tuning
Voice Call Tuning
The Voice Call Tuning feature monitors the interface between Cisco IOS software and a system's digital signaling processors (DSPs) in real time and reports status on the following: packet flow, DSP state, echo-cancellation state, and jitter state. The feature also allows you to manipulate echo-cancellation and jitter-buffer parameters in real time.
The feature is part of the standards product and is supported under normal Cisco Technical Assistance Center (TAC) procedures. No new code is required. It is backward compatible with older versions of Cisco IOS software, Cisco VCWare, and Cisco DSPWare, and accommodates the Conexant family of products.
Feature Specifications for Voice Call Tuning
Determining Platform Support Through Cisco Feature Navigator
Cisco IOS software is packaged in feature sets that are supported on specific platforms. To get updated information regarding platform support for this feature, access Cisco Feature Navigator. Cisco Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.
Cisco Feature Navigator is a web-based tool that enables you to determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image. You can search by feature or release. Under the release section, you can compare releases side by side to display both the features unique to each software release and the features in common.
To access Cisco Feature Navigator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions found at this URL:
Cisco Feature Navigator is updated regularly when major Cisco IOS software releases and technology releases occur. For the most current information, go to the Cisco Feature Navigator home page at the following URL:
Availability of Cisco IOS Software Images
Platform support for particular Cisco IOS software releases is dependent on the availability of the software images for those platforms. Software images for some platforms may be deferred, delayed, or changed without prior notice. For updated information about platform support and availability of software images for each Cisco IOS software release, refer to the online release notes or, if supported, Cisco Feature Navigator.
Contents
•
Restrictions for Voice Call Tuning
•
•
•
Restrictions for Voice Call Tuning
If you wish to use this feature on a Cisco AS5300 platform, refer to the Combined Version Release Notes for Cisco VCWare on Cisco AS5300 Universal Access Servers/Voice Gateways for more information about which Cisco VCWare to use with this feature.
Information About Voice Call Tuning
To configure the Voice Call Tuning feature, you must understand the following concepts:
Packet-Flow Detection
The analog signal from the telephone is digitized into pulse code modulation (PCM) signals by the voice coder-decoder (codec). The PCM samples are then passed to the compression algorithm which compresses the voice into a packet format for transmission across the WAN. On the far side of the cloud the exact same functions are performed in reverse order.
Depending on how the network is configured, the router or gateway can perform both the codec and compression functions or only one of them. For example, if an analog voice system is used, then the router or gateway performs the CODEC function and the compression function.
The Voice Call Tuning feature allows you to determine whether packets are flowing in each direction while a call is in progress.
DSP State
The Voice Call Tuning feature allows you to check whether the DSP servicing an active call is functioning properly. Explicit configuration of a periodic ping message with both the period and timeout parameters configurable catches DSPs that are in a hung state as soon as possible. A failure can then signal this event to the console log or as a triggering event to a logging functionality. The DSP can also send periodic informational messages like jitter measures, echo canceller measures, and alarms to alert you if there is an impending problem.
Echo-Cancellation State
Echo is the sound of your own voice reverberating in the telephone receiver while you are talking. When timed properly, echo is not a problem in the conversation; however, if the echo interval exceeds approximately 25 ms, it can be distracting to the speaker. Echo is controlled by ECs. By design, ECs are limited by the total amount of time they wait for the reflected speech to be received, which is known as an echo tail. The echo tail is normally 32 ms.
In the traditional telephony network, echo is generally caused by an impedance mismatch when the four-wire network is converted to the two-wire local loop. Echo cancellation is required because of packet network latency.
Echo cancellation is implemented in DSP firmware on the gateways and is independent of other functions implemented in the DSP (the DSP protocol and compression algorithm). In voice packet-based networks, ECs are built into the low-bit-rate codecs and are operated on each DSP
This feature gives you the ability to change echo canceller parameters while a call is in progress. Audible effects are immediately noticed, aiding in problem determination and resolution. You have the ability to change the echo canceller parameters (tail length and ERL threshold) in the field.
Jitter-Buffer Parameters
Jitter is a variation in the delay of received packets. At the sending side, packets are sent in a continuous stream with the packets being spaced evenly apart. Due to network congestion, improper queuing, or configuration errors, this steady stream can become lumpy, or the delay between each packet can vary instead of remaining constant.
This feature gives you the ability to change jitter-buffer parameters while a call is in progress. Audible effects are immediately noticed, aiding in problem determination and resolution. You have the ability to change the jitter buffer parameters (delay, size, fixed state or adaptive state) in the field.
How to Verify Voice Call Tuning Functionality
There are no configuration tasks for this feature. However, you can verify that the Voice Call Tuning feature is operating on your system by performing the following tasks:
Step 1
show vfc slot version vcware and show vfc slot version dspware commands that indicates whether the Cisco VCWare or DSPWare is compatible with the Cisco IOS image.Step 2
Step 3
Extended echo canceller not active for CallID callIDBasic echo canceller not active for CallID callIDConfiguration Examples for Voice Call Tuning
There are no specific configuration examples for the Voice Call Tuning feature, but you can verify that the Voice Call Tuning feature is operating on your system by performing the following tasks:
•
show vfc slot version vcware and show vfc slot version dspware commands for the Voice Call Tuning feature. Messages are output if the Cisco VCWare or DSPWare is not compatible with the Cisco IOS image. The new information is advisory only, so there is no action taken if the software is compatible or incompatible.Cisco IOS Release 12.2(13)T adds new information to the output of the show vfc slot version vcware and show vfc slot version dspware commands. Messages are output if the Cisco VCWare or DSPWare is not compatible with the Cisco IOS image. The new information is advisory only, so there is no action taken if the software is compatible or incompatible.
If the versions detected fall within the defined criteria and are compatible, nothing is output at bootup time. A confirmation line is output when the show vfc version vcware and show vfc version dspware commands are used:
Router# show vfc 1 version vcwareVoice Feature Card in Slot 1:VCWare Version : 7.35ROM Monitor Version: 1.3DSPWare Version : 3.4.46LTechnology : C549VCWare/DSPWare version compatibility OK•
Using the call-id argument is a generic means to identify active calls. If the call-id argument is omitted, the enquiry will show all active voice calls. In the following example, a list of all active calls with relevant identifying information is shown:
Router# show voice call statusCallID CID ccVdb Port DSP/Ch Called # Codec Dial-peers0x3 11D4 0x62972834 1/0/0 1/1 10001 g711ulaw 1/20x4 11D4 0x62973AD0 1/0/1 2/1 *10001 g711ulaw 2/10xA 11DB 0x62FE9D68 1/1/0 3/1 *2692 g729r8 0/26922 active calls found•
The following example shows query output from a Cisco AS5350 universal gateway using the NextPort version of the standard echo canceller:
Router# test call id 99 ?echo-canceller test echo canceller on an active voice callplayout-delay test playout-delay parametersAdditional References
For additional information related to the Voice Call Tuning feature, see the following sections:
•
•
Related Documents
Standards
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.
—
MIBs
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://tools.cisco.com/ITDIT/MIBS/servlet/index
If Cisco MIB Locator does not support the MIB information that you need, you can also obtain a list of supported MIBs and download MIBs from the Cisco MIBs page at the following URL:
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml
To access Cisco MIB Locator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions found at this URL:
RFCs
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.
—
Technical Assistance
Command Reference
This section documents modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.2 T command reference publications.
show vfc version
To show the version of the software that resides on a voice feature card (VFC), use the show vfc version command in privileged or user EXEC mode.
show vfc slot version {dspware | vcware}
Syntax Description
slot
Sot in which the VFC is installed. Valid values range from 0 to 2.
dspware
Specifies the DSPWare version.
vcware
Specifies the Cisco VCWare version.
Command Modes
Privileged or user EXEC
Command History
Usage Guidelines
Messages are output if the Cisco VCWare or DSPWare is not compatible with the Cisco IOS image. The new information is advisory only. You need take no action if the software is incompatible.
Examples
If the versions detected fall within the defined criteria and are compatible, nothing is output at bootup time. A confirmation line is output when the show vfc version vcware and show vfc version dspware commands are used:
Router# show vfc 1 version vcwareVoice Feature Card in Slot 1:VCWare Version : 7.35ROM Monitor Version: 1.3DSPWare Version : 3.4.46LTechnology : C549VCWare/DSPWare version compatibility OKRouter# show vfc 1 version dspwareDSPWare version in VFC slot 1 is 3.4.46LVCWare/DSPWare version compatibility OKIf the found versions are out of range or otherwise mismatched, a representative message is output when you boot up the router or is appended to the output of the commands. Other than the output of these messages, the version check has no other effect, and the software functions normally. The following example shows a found version that is out of range or mismatched at bootup:
...Firmware version mismatch for bundle AS5300 VCWare- version found (6.04) is lower than minimum required (7.35)Firmware version mismatch for bundle AS5300 C549- version found (3.3.10L) is lower than minimum required (3.4.46L)If you were to enter an explicit request and the software was incompatible, the following appears:
Router# show vfc 1 version vcwareVoice Feature Card in Slot 1:VCWare Version : 6.04ROM Monitor Version: 1.3DSPWare Version : 3.3.10LTechnology : C549Firmware version mismatch for bundle AS5300 VCWare- version found (6.04) is lower than minimum required (7.14)Firmware version mismatch for bundle AS5300 C549- version found (3.3.10L) is lower than minimum required (3.4.26L)Router# show vfc 1 version dspwareDSPWare version in VFC slot 1 is 3.3.10LFirmware version mismatch for bundle AS5300 VCWare- version found (6.04) is lower than minimum required (7.14)Firmware version mismatch for bundle AS5300 C549- version found (3.3.10L) is lower than minimum required (3.4.26L)Table 1 Describes significant fields shown in the command output for the show vfc version vcware command with compatible firmware.
Table 2 shows output field descriptions for the show vfc version dspware command with compatible firmware.
Related Commands
show voice call
To show the real-time call status for voice ports, including packet flow indication, DSP state, echo canceller state, and jitter state, use the show voice call command in either user EXEC or privileged EXEC mode.
Cisco 1700 Series and Cisco 7750 with Analog Voice Ports
show voice call [slot/port | summary call-id | status] [sample sample-period]
Cisco 2600, Cisco 3600, and Cisco 3700 Series with Analog Voice Ports
show voice call [slot/subunit/port | summary call-id | status] [sample sample-period]
Cisco 2600, Cisco 3600, and Cisco 3700 Series with Digital Voice Ports (with T1 Packet Voice Trunk Network Modules)
show voice call [slot/port:ds0-group | summary call-id | status] [sample sample-period]
Cisco 7200 and Cisco 7500 Series with Digital Voice Ports
show voice call [slot/port:ds0-group | summary call-id | status] [sample sample-period]
Cisco 827 with Analog Voice Ports
show voice call [slot/port | summary call-id | status] [sample sample-period]
Cisco AS5300, Cisco AS5350, Cisco AS5400, Cisco AS5800, and Cisco AS5850 with Analog Voice Ports
show voice call [slot/port:ds0-group | summary call-id | status] [sample sample-period]
Cisco CVA122 with Analog Voice Ports
show voice call [slot/subunit/port | summary call-id | status] [sample sample-period]
Cisco MC3810 with Analog Voice Ports
show voice call [slot/port | summary call-id | status] [sample sample-period]
Cisco MC3810 with Digital Voice Ports
show voice call [slot:ds0-group | summary call-id | status] [sample sample-period]
Cisco uBR92x with Analog Voice Ports
show voice call [slot/subunit/port | summary call-id | status] [sample sample-period]
Cisco VG200 with Analog Voice Ports
show voice call [slot/subunit/port | summary call-id | status] [sample sample-period]
Cisco VG200 with Digital Voice Ports
show voice call [slot/port:ds0-group | summary call-id | status] [sample sample-period]
For the Cisco 1700 Series and Cisco 7750 with Analog Voice Ports:
For Cisco 2600, Cisco 3600, and Cisco 3700 Series with Analog Voice Ports:
For Cisco 2600, Cisco 3600, and Cisco Series with Digital Voice Ports:
For the Cisco 7200 Series with Digital Voice Ports:
For the Cisco AS5300 Series with Digital Voice Ports
Note
For the Cisco AS5350 Series with Digital Voice Ports:
For the Cisco AS5400 Series with Digital Voice Ports:
For the Cisco AS5800 Series with Digital Voice Ports:
For the Cisco CVA122 with Digital Voice Ports:
For the Cisco MC3810 with Analog Voice Ports:
For the Cisco MC3810 with Digital Voice Ports:
For the Cisco uBR92x with Analog Voice Ports:
For the Cisco VG200 with Analog Voice Ports:
Command Modes
User EXEC or privileged EXEC
Command History
Usage Guidelines
This command applies to Voice over Frame Relay, Voice over ATM, and Voice over IP.
This command shows call-processing and protocol state-machine information for a voice port, if it is available. It also shows information on the DSP channel associated with the voice port, if it is available. All real-time information in the DSP channel, such as jitter and buffer overrun for example, is queried to the DSP channel, and asynchronous responses are returned to the host side.
If no call is active on a voice port, the show voice call summary command displays only the VPM (shutdown) state. If a call is active on a voice port, the VTSPS state is shown. For an on-net call or a local call without local-bypass (not cross-connected), the CODEC and VAD fields are displayed. For an off-net call or a local call with local-bypass, the CODEC and VAD fields are not displayed.
Note
CODEC and VAD are not displayed by the show voice call command because this information is in the summary display.
The show voice call command provides the status at these levels of the call handling module:
•
•
•
•
If you use the show voice call status command by itself, an immediate list of all the active calls is shown. You can use the call-id argument to request that the digital signal processor (DSP) associated with the call-id be queried for run-time statistics twice, once immediately and a second time after sample sample-period seconds.
The sample sample-period is the number of seconds over which the status is to be determined, ranging from 1 to 30 seconds. If sample sample-period is omitted, a default of 10 seconds is used. The results of the run-time statistic queries are then analyzed and presented in a one-line summary format.
When a call terminates during the specified sample period, the following output message is returned:
CallID call id cannot be queriedCallID call id second sample responses unavailableWhen using the test call id command, you must specify a call ID. The call ID is obtained by using the show voice call status command. The following is an example of how to obtain the call ID parameter that will be the value used in the call-id argument. The first parameter displayed in the output shows the call ID.
Note
On a router that supports large numbers of active calls, the | (pipe) option can be used. The following keywords can be used to reduce and select the output:
Refer to the Extended ITU-T G.168 Echo Cancellation feature module for more information about the extended echo canceller.
Examples
The following is a sample display from the show voice call summary command for voice ports on a Cisco MC3810, showing two local calls connected without local bypass:
PORT CODEC VAD VTSP STATE VPM STATE======= ======== === ===================== ========================0:17.18 *shutdown*0:18.19 g729ar8 n S_CONNECT FXOLS_OFFHOOK0:19.20 FXOLS_ONHOOK0:20.21 FXOLS_ONHOOK0:21.22 FXOLS_ONHOOK0:22.23 FXOLS_ONHOOK0:23.24 EM_ONHOOK1/1 FXSLS_ONHOOK1/2 FXSLS_ONHOOK1/3 EM_ONHOOK1/4 EM_ONHOOK1/5 FXOLS_ONHOOK1/6 g729ar8 n S_CONNECT FXOLS_CONNECTThe following is a sample display from the show voice call summary command for voice ports on a Cisco MC3810, showing two local calls connected with local bypass:
PORT CODEC VAD VTSP STATE VPM STATE======= ======== === ===================== ========================0:17.18 *shutdown*0:18.19 S_CONNECT FXOLS_OFFHOOK0:19.20 FXOLS_ONHOOK0:20.21 FXOLS_ONHOOK0:21.22 FXOLS_ONHOOK0:22.23 FXOLS_ONHOOK0:23.24 EM_ONHOOK1/1 FXSLS_ONHOOK1/2 FXSLS_ONHOOK1/3 EM_ONHOOK1/4 EM_ONHOOK1/5 FXOLS_ONHOOK1/6 S_CONNECT FXOLS_CONNECTThe following is a sample display from the show voice call command for analog voice ports on a Cisco MC3810:
1/1 vpm level 1 state = FXSLS_ONHOOKvpm level 0 state = S_UP1/2 vpm level 1 state = FXSLS_ONHOOKvpm level 0 state = S_UP1/3 is shutdown1/4 vtsp level 0 state = S_CONNECTvpm level 1 state = S_TRUNKEDvpm level 0 state = S_UP1/5 vpm level 1 state = EM_ONHOOKvpm level 0 state = S_UP1/6 vpm level 1 state = EM_ONHOOKvpm level 0 state = S_UPsys252#show voice call 1/41/4 vtsp level 0 state = S_CONNECTvpm level 1 state = S_TRUNKEDvpm level 0 state = S_UProuter# ***DSP VOICE VP_DELAY STATISTICS***Clk Offset(ms): 1445779863, Rx Delay Est(ms): 95Rx Delay Lo Water Mark(ms): 95, Rx Delay Hi Water Mark(ms): 125***DSP VOICE VP_ERROR STATISTICS***Predict Conceal(ms): 10, Interpolate Conceal(ms): 0Silence Conceal(ms): 0, Retroact Mem Update(ms): 0Buf Overflow Discard(ms): 20, Talkspurt Endpoint Detect Err: 0***DSP VOICE RX STATISTICS***Rx Vox/Fax Pkts: 537, Rx Signal Pkts: 0, Rx Comfort Pkts: 0Rx Dur(ms): 50304730, Rx Vox Dur(ms): 16090, Rx Fax Dur(ms): 0Rx Non-seq Pkts: 0, Rx Bad Hdr Pkts: 0Rx Early Pkts: 0, Rx Late Pkts: 0***DSP VOICE TX STATISTICS***Tx Vox/Fax Pkts: 567, Tx Sig Pkts: 0, Tx Comfort Pkts: 0Tx Dur(ms): 50304730, Tx Vox Dur(ms): 17010, Tx Fax Dur(ms): 0***DSP VOICE ERROR STATISTICS***Rx Pkt Drops(Invalid Header): 0, Tx Pkt Drops(HPI SAM Overflow): 0***DSP LEVELS***TDM Bus Levels(dBm0): Rx -70.3 from PBX/Phone, Tx -68.0 to PBX/PhoneTDM ACOM Levels(dBm0): +2.0, TDM ERL Level(dBm0): +5.6TDM Bgd Levels(dBm0): -71.4, with activity being voiceThe following is a sample display of the show voice call status command on the Cisco 2600 series. You can use this command to obtain the call-ID rather than the show call active brief command; the call ID output of the show voice call status command is already in hex form.
Router# show voice call statusCallID CID ccVdb Port DSP/Ch Called # Codec Dial-peers0x1 11CE 0x02407B20 1:0.1 1/1 1000 g711ulaw 2000/10001 active call foundUsing the call-id argument is a generic means to identify active calls. If the call-id is omitted, the enquiry shows all active voice calls. In the following example, shows a list of all active calls with relevant identifying information is shown:
Router# show voice call statusCallID CID ccVdb Port DSP/Ch Called # Codec Dial-peers0x3 11D4 0x62972834 1/0/0 1/1 10001 g711ulaw 1/20x4 11D4 0x62973AD0 1/0/1 2/1 *10001 g711ulaw 2/10xA 11DB 0x62FE9D68 1/1/0 3/1 *2692 g729r8 0/26922 active calls foundThe following example shows echo return loss (ERL) reflector information where 3 is the call-id and the sample-period is 10 seconds:
Router# show voice call status 3 sample 10Gathering information (10 seconds)...CallID Port DSP/Ch Codec Rx/Tx ERL Jitter0x3 1/0/0 1/1 g711ulaw 742/154 5.6 50/15In this example, the value under the ERL column is a measure of the echo return loss (in dB) as reported by the DSP. The values under the Jitter column are the current values of the delay and the jitter of the packets around that delay.
If the router is running the extended echo canceller, output looks similar to the following when using the command above. The output shows a new value under ERL/Reflctr. This is a millisecond measure of the time difference between the original signal and the loudest echo (peak reflector) as detected by the echo canceller.
Gathering information (10 seconds)...CallID Port DSP/Ch Codec Rx/Tx ERL/Reflctr Jitter0x3 1/0/0 1/1 g711ulaw 742/154 5.6/12 50/15The following example shows output using the NextPort version of the standard echo canceller. (Time-slot information is also in the output for digital ports.)
Router# show voice call statusCallID CID ccVdb Port DSP/Ch Called # Codec Dial-peers0x97 12BB 0x641B0F68 3/0:D.1 1012/2 31001 g711ulaw 3/310000x99 12BE 0x641B0F68 3/0:D.2 1012/3 31002 g711ulaw 3/310002 active calls foundRouter# show voice call statusCallID CID ccVdb Port DSP/Ch Called # Codec Dial-peers0x2 11D1 0x62FE6478 1/0/0 1/1 10001 g711ulaw 1/20x3 11D1 0x62FE80F0 1/0/1 2/1 *10001 g711ulaw 2/11 active call foundThe following shows keyword choices when using the show voice call command with the | (pipe) option:
Router# show voice call | ?append Append redirected output to URL (URLs supporting append operationonly)begin Begin with the line that matchesexclude Exclude lines that matchinclude Include lines that matchredirect Redirect output to a URLtee Copy output to a URLTable 3 describes significant fields shown for the show voice call status command.
Related Commands
test call id
To manipulate echo-canceller and jitter-buffer parameters in real time, use the test call id command in privileged EXEC mode.
test call id call-id [echo-canceller [coverage range] [erl worst-case [0 | 3 | 6]] [h-register [clear | freeze| thaw]] | [playout-delay [fixed fixed-delay]] | [adaptive nominal-delay min-delay max-delay]]
Syntax Description
call-id
The hexadecimal ID of an active voice call. Values can be 0-FFFFFFFF.
echo-canceller
(Optional) Tests the echo canceller on an active voice call.
coverage range
(Optional) Tests echo canceller coverage in milliseconds. Valid values are 0, 8, 16, 24, 32, 48, 64, and 128. Specific default values depend on your echo canceller firmware:
•
•
•
See the Usage Guidelines for more information about default values.
erl worst-case [0 | 3 | 6]
(Optional) Worst-case echo return loss (ERL), in decibels. Valid values are 0, 3, or 6. Default is 6.
Note
h-register
Controls the extended echo canceller H-register
[clear | freeze| thaw]
clear—Clears a call in the extended echo canceller H-register
freeze—Freezes a call in the extended echo canceller H-register
thaw—Thaws a call in the extended echo canceller H-register
playout-delay
(Optional) Resets the playout buffering on the associated digital signal processors (DSPs) to the requested values. If fixed fixed-delay is selected, the first parameter only is required and used. If all three parameters are used, they are accepted, but the last two are ignored. If adaptive nominal-delay min-delay max-delay is selected, all three values are required and used.
fixed fixed-delay
(Optional) Tests the fixed playout-delay mode. Jitter buffer size does not adjust during a call; a constant playout delay is added. The fixed-delay argument is nominal delay in ms. Range is from 0 to 1500.
adaptive nominal-delay min-delay max-delay
(Optional) Tests the adaptive playout-delay mode. Adjusts jitter buffer size and amount of playout delay during a call on the basis of current network conditions. If the adaptive keyword is used, min-delay, nominal-delay, and max-delay are sanity checked for maximum delay being greater than or equal to the nominal delay, which is greater than or equal to the minimum delay.
Minimum delay range is from 10 to 80. Nominal delay range is from 0 to 1500. Maximum delay range is from 40 to 1700.
Note
Command Modes
Privileged EXEC
Command History
12.2(13)T
This command was introduced on all voice platforms with echo cancellation and extended echo cancellation.
Usage Guidelines
Obtain the call-id argument value by using the show voice call status command. The following example shows how to obtain the call ID. The first parameter displayed in the output shows the call ID.
Note
Router# show voice call statusCallID CID ccVdb Port DSP/Ch Called # Codec Dial-peers0x2 11D1 0x62FE6478 1/0/0 1/1 10001 g711ulaw 1/20x3 11D1 0x62FE80F0 1/0/1 2/1 *10001 g711ulaw 2/11 active call foundSome of the options in the Syntax Description table can be used only on specific platforms running the extended echo canceller. Table 4 lists the platforms supported with this feature and whether the standard (TI C54x voice-based platforms) or the extended (NextPort/Conexant voice-based platforms) echo canceller is available on that platform. 0 indicates a disabled state.
Specified parameters are sent to the DSP using the normal DSP control-message mechanism expecting an immediate effect. You can expect a short discontinuity and settling period for the voice stream. These parameters have effect only for the duration of the call. Echo-canceller and playout parameters revert to the values defined in the configuration on the next call using that DSP.
You can use this command with the extended echo canceller, which allows you to configure the voice card in a router individually, or with the standard echo canceller, allows you to configure the router as a whole. The following two new output might appear when either an extended-only or a standard-only echo cancellation function is requested:
Extended echo canceller not active for CallID callIDBasic echo canceller not active for CallID callIDYou can display which version of echo canceller is running and if it is valid for the requested function. For example:
Router# test call id 3 echo-canceller erl worst-case ?0 worst case extended echo canceller operation at 0 dB ERL3 worst case extended echo canceller operation at 3 dB ERL6 worst case extended echo canceller operation at 6 dB ERRouter# test call id 3 echo-canceller coverage ?0 disable echo-canceller16 16 ms echo canceller coverage (basic only)24 24 ms echo canceller coverage (basic & extended)32 32 ms echo canceller coverage (basic & extended)48 48 ms echo canceller coverage (extended only)64 64 ms echo canceller coverage (extended only)8 8 ms echo canceller coverage (basic only)In its section on testing echo cancellers, the ITU-T specification G.168 invents a hypothetical device in the EC called an H-register. The H-register stores the impulse response of the echo path and invents actions such as "clear the H register," "contents of the H register are frozen," and "thaw" to undo the "freeze." The H-register is the filter within EC used to estimate the echo. If it freezes, its filter coefficients do not adapt to the signal. If there is a significant change in the signal characteristic, such as power level or delay, echo is heard. jjj
The H-register test mode settings allow manual manipulation of the EC H-register for G.168-like tests. Actual G.168 testing is embedded in the digital signal processor (DSP) and does not require explicit Cisco IOS control of the H-register. The call ID must be a valid active telephony call leg ID as displayed by entering the show call active brief command in privileged EXEC mode.
Refer to the Extended ITU-T G.168 Echo Cancellation feature module for more information about the extended echo canceller.
Examples
The following example shows how to set the fixed delay to 0, which is the minimum value allowed:
Router# test call id 99 playout-delay fixed 0The following example shows how to set the minimum delay, nominal delay, and maximum delay. In this example, the maximum value allowed for each parameter is implemented:
Router# test call id 99 playout-delay adaptive 80 1500 1700The following example shows how to test the echo canceller on an active voice call on a Cisco AS5350 using the NextPort version of the standard echo canceller and a call ID value of 99:
Router# test call id 99 echo-cancellerThe following example shows how to test the playout delay parameters on an active voice call on a Cisco AS5350 using the NextPort version of the standard echo canceller and a call ID value of 99:
Router# test call id 99 playout-delayThe following example tests echo canceller coverage using a call ID value of 99:
Router# test call id 99 echo-canceller coverageThe following example tests extended echo canceller ERL parameters using a call ID value of 99:
Router# test call id 99 echo-canceller erlThe following example controls the extended echo canceller H-register using a call ID value of 99:
Router# test call id 99 echo-canceller h-registerThe echo-canceller coverage keywords reset the echo canceller range on the associated DSPs to the new value, where 0 is the equivalent of switching the echo canceller off. Each value in the list shows whether it is supported on the basic or the extended echo canceller.
Router# test call id 99 echo-canceller coverage ?0 disable echo-canceller16 16 ms echo canceller coverage (basic only)24 24 ms echo canceller coverage (basic & extended)32 32 ms echo canceller coverage (basic & extended)48 48 ms echo canceller coverage (extended only)64 64 ms echo canceller coverage (extended only)8 8 ms echo canceller coverage (basic only)The erl worst-case [0 | 3 | 6] syntax reflects the new tunable argument available with the extended echo canceller only.
Router# test call id 99 echo-canceller erl ?worst-case test extended echo canceller worst-case erlRouter# test call id 99 echo-canceller erl worst-case ?0 worst case extended echo canceller operation at 0 dB ERL3 worst case extended echo canceller operation at 3 dB ERL6 worst case extended echo canceller operation at 6 dB ERLThe following is example output from the test call command in privileged EXEC mode using a value of 02 for the call ID argument:
Router# test call ID 02 echo-canceller h-register ?clear Clear call echo canceller h registerfreeze Freeze call echo canceller h registerthaw Thaw call echo canceller h registerRelated Commands
Glossary
API—application programming interface.
CLI—command-line interface.
DSP—digital signal processor.
DSPWare—The total load of code that runs in a DSP for voice processing. The code is embedded in the Cisco IOS image for a platform.
HPI—host port interface, used with the TI C54x class of DSP.
PCM—pulse code modulation.
RTP—Real-Time Transport Protocol.
TDM—time-division multiplexing.
TI C54x—Texas Instruments C54x family of DSPs, including the C542, C549, C5409, C5410.
VCWare—Code image that runs on each VFC in a Cisco AS5300 system. Embeds the DSPWare that the Cisco AS5300 uses.
VFC—voice feature card.
