callpres

Table Of Contents

Call Preservation for H.323 VoIP Calls

Contents

Prerequisites for Call Preservation for H.323 VoIP Calls

Restrictions for Call Preservation for H.323 VoIP Calls

Information About Call Preservation for H.323 VoIP Calls

Management

How to Configure Call Preservation for H.323 VoIP Calls

Configure Cisco IOS Gateway

Configure H.323 VoIP Call Preservation for All Calls

Examples

Configure H.323 VoIP Call Preservation for a Dial Peer

Examples

Troubleshooting Tips

What to Do Next

Configure Cisco CallManager

Configuration Examples for Call Preservation for H.323 VoIP Calls

H.323 VoIP Call Preservation for All Calls Example

H.323 VoIP Call Preservation for a Dial Peer Example

H.323 Call Preservation for RTP and RTCP and Silence Detection Example

RTP and RTCP Inactivity Detection Configuration Example

Bidirectional Silence Detection Enable Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

call preserve

show h323 calls preserved

Open Source License Acknowledgements

OpenSSL/Open SSL Project

License Issues

Glossary

Call Preservation for H.323 VoIP Calls

---

Revised: December 12, 2005

History for Call Preservation for H.323 VoIP Calls Feature

Release	Cisco CallManager Express (Cisco CME) Version	Modification
12.4(4)XC	4.0	This feature was introduced.

Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

Contents

•Prerequisites for Call Preservation for H.323 VoIP Calls

•Restrictions for Call Preservation for H.323 VoIP Calls

•Information About Call Preservation for H.323 VoIP Calls

•How to Configure Call Preservation for H.323 VoIP Calls

•Configuration Examples for Call Preservation for H.323 VoIP Calls

•Additional References

•Command Reference

•Open Source License Acknowledgements

•Open Source License Acknowledgements

Prerequisites for Call Preservation for H.323 VoIP Calls

•For bidirectional silence detection, Cisco IOS gateways with 5510 digital signal processors (DSPs) are needed.

•It is recommended that media inactivity detection be configured so that preserved calls are torn down after conversations are over. Two available media inactivity detection features are discussed in the "How to Configure Call Preservation for H.323 VoIP Calls" section. They are Real-time Transport Protocol (RTP) and RTP Control Protocol (RTCP) inactivity detection and bidirectional silence detection. For more information about media inactivity detection, see the "Configuring Media Inactive Call Detection" chapter in the Cisco IOS Tcl IVR and VoiceXML Application Guide —12.3(14)T and Later.

Restrictions for Call Preservation for H.323 VoIP Calls

Call preservation for H.323 VoIP calls does not support the following:

•Calls in transient call states.

•Calls in for which a H.225.0 connection has not occurred,

•Calls on which supplementary services are in progress. For example, when one of the parties is on hold.

•Calls that involve a media resource located across a WAN, such as conference resources.

•Calls where the two parties are registered to different CallManager clusters.

Information About Call Preservation for H.323 VoIP Calls

This feature expands Cisco Survivable Remote Site Telephony's (Cisco SRST's) call preservation functionality to include the following types of failures and connections:

Failure Types

•WAN failures that include WAN links flapping or degraded WAN links

•Cisco CallManager software failure, such as when the ccm.exe service crashes on a Cisco CallManager server.

•LAN connectivity failure, except when a failure occurs at the local branch

Connection Types

•Calls between two Cisco CallManager controlled endpoints

–During Cisco CallManager reloads

–When a Transmission Control Protocol (TCP) connection between one or both endpoints and Cisco CallManager used for signaling H.225.0 or H.245 messages is lost or flapping

–Between endpoints that are registered to different Cisco CallManagers in a cluster and the TCP connection between the two Cisco CallManagers is lost

–Between IP phones and the PSTN at the same site

•Calls between Cisco IOS gateway and an endpoint controlled by a softswitch where the signaling (H.225.0, H.245 or both) flows between the gateway and the softswitch and media flows between the gateway and the endpoint.

–When the softswitch reloads.

–When the H.225.0 or H.245 TCP connection between the gateway and the softswitch is lost, and the softswitch does not clear the call on the endpoint

–When the H.225.0 or H.245 TCP connection between softswitch and the endpoint is lost, and the soft-switch does not clear the call on the gateway

•Call flows that involve a Cisco IP in IP (IPIP) gateway running in media flow-around mode that reload or lose connection with the rest of the network

Note that after the media is preserved, the call is torn down later when either one of the parties hangs up or media inactivity is detected. In cases where there is a machine-generated media stream, such as music streaming from a media server, the media inactivity detection will not work and the call may hang. Cisco CallManager addresses such conditions by indicating to the gateway that such calls should not be preserved, but third-party devices or IPIP gateways would not do this.

Flapping is defined for this feature as the repeated and temporary loss of IP connectivity that can be caused by WAN or LAN failures. H.323 VoIP calls between a Cisco IOS gateway and Cisco CallManager may be torn down when flapping occurs. When Cisco CallManager detects that the TCP connection is lost, it clears the call and closes the TCP sockets used for the call by sending a TCP FIN, without sending an "H.225.0 Release Complete" or "H.245 End Session" message. This is called quiet clearing. The TCP FIN sent from the Cisco CallManager could reach the gateway if the network comes up for a short duration, and the gateway will tear the call down. Even if the TCP FIN does not reach the gateway, the TCP keepalives sent from the gateway could reach Cisco CallManager when the network comes up. Cisco CallManager will send TCP RST messages in response to the keepalives as it has already closed the TCP connection. The gateway will tear down H.323 calls if it receives the RST message.

Configuration of the Call Preservation for H.323 VoIP Calls feature involves configuring the call preserve command and enabling the "Allow Peer to Preserve H.323 Calls" parameter from Cisco CallManager's Service Parameters window.

The call preserve command causes the gateway to ignore socket closure or socket errors on H.225.0 or H.245 connections for active calls, allowing the socket to be closed without tearing down calls using those connections.

The Cisco CallManager's "Allow Peer to Preserve H.323 Calls" parameter preserves the following:

•Active H323 calls with quiet clear triggered by the other half of the call

•Active H323 calls with TCP socket closed on the H.323 end before the H.225 or H.245 release signal is received

•Active H323 calls with a signal distribution layer (SDL) link that is out of service and detected on the H323 end

Management

Call preservation may be reported through Syslog, which optionally can be obtained through a simple network management protocol (SNMP) trap. New syslog messages are printed when call preservation is applied. An SNMP trap can be configured on this syslog message, so you can be notified when call preservation occurs on a gateway.

Preservation information is displayed through the show h323 calls preserved command. The following is an example of the command's output:

CallID = 11EC , Calling Number = , Called Number = 3210000 , 
RemoteSignallingIPAddress=9.13.0.26 , RemoteSignallingPort=49760 , 
RemoteMediaIPAddress=9.13.0.11 , RemoteMediaPort=17910 , Preserved Duration = 262 , Total 
Duration = 562 , H225 FD = -1 , H245 FD = -1

The previous example represents one preserved call. One such display is provided per preserved call. The show h323 calls preserved displays active calls only. No history is output.

To obtain additional information about a call, you can also use the show call active voice command. Calls can be cleared with the clear call voice causecode command.

How to Configure Call Preservation for H.323 VoIP Calls

The tasks for configuring Call Preservation for H.323 VoIP Calls include the following:

•Configure Cisco IOS Gateway

•Configure Cisco CallManager

Configure Cisco IOS Gateway

The call preserve command activates H.323 VoIP call preservation. RTP and RTCP inactivity detection and bidirectional silence detection can be used with this feature. Note that voice activity detection (VAD) must be set to off if you are using RTP and RTCP inactivity detection. VAD may be set to on, for bidirectional silence detection. For configuration examples, see the "RTP and RTCP Inactivity Detection Configuration Example" section and "Bidirectional Silence Detection Enable Example" section.

When bidirectional silence and RTP and RTCP inactivity detection are configured, they are enabled for all calls by default. To enable them for H.323 VoIP preserved calls only, you must use the call preserve command's limit-media-detection keyword.

H.323 VoIP call preservation can be applied to all calls and to dial peers. The required steps are described in the following sections:

•Configure H.323 VoIP Call Preservation for All Calls

•Configure H.323 VoIP Call Preservation for a Dial Peer

Configure H.323 VoIP Call Preservation for All Calls

The following describes how to configure H.323 VoIP call preservation for all calls.

SUMMARY STEPS

1. enable

2. configure terminal

3. voice service voip

4. h323

5. call preserve [limit-media-detection]

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	voice service voip Example: Router (config)# voice service voip	Enters voice-service configuration mode.
Step 4	h323 Example: Router (config-voi-serv)# h323	Enables the H.323 voice service configuration commands.
Step 5	call preserve [limit-media-detection] Example: Router (config-voi-h323)# call preserve	Enables the preservation of H.323 VoIP calls. •limit-media-detection—Limits RTP and RTCP inactivity detection and bidirectional silence detection (if configured) to H.323 VoIP preserved calls only.
Step 6	exit Example: Router# exit	Exits H.323 configuration mode.
Step 7	exit Example: Router# exit	Exist voice service voip configuration mode.

Examples

The following configuration example enables H.323 VoIP call preservation for all calls.

voice service voip

 h323

  call preserve 

The following configuration example enables H.323 VoIP call preservation and limits RTP and RTCP inactivity detection and bidirectional silence detection (if configured) to preserved calls only:

voice service voip

 h323

  call preserve limit-media-detection

Configure H.323 VoIP Call Preservation for a Dial Peer

The following describes how to configure H.323 VoIP call preservation for a dial peer.

SUMMARY STEPS

1. enable

2. configure terminal

3. voice-class h323 tag

4. call preserve [limit-media-detection]

5. exit

6. dial-peer voice tag voip

7. voice-class h323 tag

8. exit

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	voice-class h323 tag Example: Router (config)# voice-class h323 4	Assigns an H.323 voice class to a VoIP dial peer. •tag—Unique number to identify the voice class. Range is from 1 to 10000.
Step 4	call preserve [limit-media-detection] Example: Router (config-class)# call preserve	Enables the preservation of H.323 VoIP calls. •limit-media-detection—Limits RTP and RTCP inactivity detection and bidirectional silence detection (if configured) to H.323 VoIP preserved calls only.
Step 5	exit Example: Router (config)# exit	Exits H.323 voice class configuration mode.
Step 6	dial-peer voice tag voip Example: Router (config)# dial-peer voice 1 voip	Defines a particular dial peer.
Step 7	voice-class h323 tag Example: Router (config-dial-peer)# voice-class h323 4	Assigns an H.323 voice class to a VoIP dial peer. •tag—Unique number to identify the voice class. Range is from 1 to 10000.
Step 8	exit Example: Router# exit	Exits dial-peer voice configuration mode.

Examples

The following configuration example enables H.323 VoIP call preservation for dial peer 1.

voice-class h323 4 

 call preserve

dial-peer voice 1 voip

 voice-class h323 4 

Troubleshooting Tips

•Enable the voice iec syslog command in global configuration mode to display the reason that a call has disconnected after call preservation. The following is an example of the voice iec syslog command output line that display this information:

Nov 29 12:39:55.167: %VOICE_IEC-3-GW: H323: Internal Error (Socket error):

•Calls on hold are not preserved and a non-standard message with "callPreserveIE FALSE" is sent in the notify message. Use the debug h225 asn command for debug. The following is example output:

Router# debug h225 asn

H.225 ASN1 Messages debugging is on

3725-GW1#

*May 3 15:57:27.920: H225.0 INCOMING ENCODE BUFFER::= 
28501900060008914A00040000D2D6D6D87EB11D02000000090D194410A00100110140B50000120A80A480
04000101000100

*May 3 15:57:27.920: 

*May 3 15:57:27.920: H225.0 INCOMING PDU ::=

value H323_UserInformation ::= 

{

h323-uu-pdu 

{

h323-message-body notify : 

{

protocolIdentifier { 0 0 8 2250 0 4 }

callIdentifier 

{

guid '00D2D6D6D87EB11D02000000090D1944'H

}

}

h245Tunneling FALSE

nonStandardControl 

{

{

nonStandardIdentifier h221NonStandard : 

{

t35CountryCode 181

t35Extension 0

manufacturerCode 18

}

data '80A48004000101000100'H

}

}

}

}

*May 3 15:57:27.924: H225 NONSTD INCOMING ENCODE BUFFER::= 80A48004000101000100

*May 3 15:57:27.924: 

*May 3 15:57:27.924: H225 NONSTD INCOMING PDU ::=

value H323_UU_NonStdInfo ::= 

{

callMgrParam 

{

interclusterVersion 1

enterpriseID {}

}

callPreserveParam 

{

callPreserveIE FALSE

}

}

When the call is resumed, "callPreserve" is again set to True as shown in the following output example:

Router# debug h225 asn

*May 3 15:57:32.676: H225.0 INCOMING ENCODE BUFFER::= 
28501900060008914A00040000D2D6D6D87EB11D02000000090D194410A001001B0140B50000121480A680
04000101000943004C0580323030300140

*May 3 15:57:32.676: 

*May 3 15:57:32.676: H225.0 INCOMING PDU ::=

value H323_UserInformation ::= 

{

h323-uu-pdu 

{

h323-message-body notify : 

{

protocolIdentifier { 0 0 8 2250 0 4 }

callIdentifier 

{

guid '00D2D6D6D87EB11D02000000090D1944'H

}

}

h245Tunneling FALSE

nonStandardControl 

{

{

nonStandardIdentifier h221NonStandard : 

{

t35CountryCode 181

t35Extension 0

manufacturerCode 18

}

data '80A68004000101000943004C0580323030300140'H

}

}

}

}

*May 3 15:57:32.680: H225 NONSTD INCOMING ENCODE BUFFER::= 
80A68004000101000943004C0580323030300140

*May 3 15:57:32.680: 

*May 3 15:57:32.680: H225 NONSTD INCOMING PDU ::=

value H323_UU_NonStdInfo ::= 

{

callMgrParam 

{

interclusterVersion 1

enterpriseID {}

}

callSignallingParam 

{

connectedNumber '4C058032303030'H

}

callPreserveParam 

{

callPreserveIE TRUE

}

}

•Use the debug cch323 all command after call setup to see if call is going into preserved state. Note that this command generates verbose output, and a console message is printed for every preserved call. In the following output, the relevant information appears in boldface:

Router# debug cch323 all

(CCH323-6-CALL_PRESERVED).

Nov 29 12:39:55.167: //-1/xxxxxxxxxxxx/H323/cch323_ct_main: SOCK 3 Event 0x1

Nov 29 12:39:55.167: //31/A9E0FB268017/H323/cch323_h225_handle_conn_loss: 
cch323_h225_handle_conn_loss Call not torn down despite H.225.0 socket error: socket 
error status = 1, ccb status = 403760899, fd = 3, pre-V3 = 0

Nov 29 12:39:55.167: %CCH323-6-CALL_PRESERVED: cch323_h225_handle_conn_loss: H.323 
call preserved due to socket closure or error, Call Id = 4593, fd = 3

Nov 29 12:39:55.167: %VOICE_IEC-3-GW: H323: Internal Error (Socket error): 
IEC=1.1.186.5.7.6 on callID 31 GUID=A9E0FB26600B11DA8017000653455072

Nov 29 12:39:55.167: //-1/xxxxxxxxxxxx/H323/h323_set_release_source_for_peer: 
ownCallId[31], src[6]

Nov 29 12:39:55.167: //-1/xxxxxxxxxxxx/H323/h323_gw_clean_send_blocked_watch: fd 3

Nov 29 12:39:55.167: //-1/xxxxxxxxxxxx/H323/cch323_cleanup_xport: hashDestroy for 
TcpFDTbl

•The following are additional debug commands can be used to troubleshoot the problems associated with H.323 VoIP call preservation:

–debug h225 asn1

–debug h225 q931

–debug h245 asn1

What to Do Next

Configure Cisco CallManager.

Configure Cisco CallManager

This section describes how to configure Cisco CallManager for the call preservation of H.323 VoIP calls.

Procedure

---

Step 1 Choose Service > Service Parameters.

Step 2 From the Service menu select Cisco CallManager.

Step 3 Click Advanced.

Step 4 Scroll to the Clusterwide Parameter (Device — H.323) section.

Step 5 Set the "Allow Peer to Preserve H.323 Calls" parameter to True.

Step 6 At the top of the screen click Update.

---

Configuration Examples for Call Preservation for H.323 VoIP Calls

The configuration examples in this section include the following:

•H.323 VoIP Call Preservation for All Calls Example

•H.323 VoIP Call Preservation for a Dial Peer Example

•H.323 Call Preservation for RTP and RTCP and Silence Detection Example

•RTP and RTCP Inactivity Detection Configuration Example

•Bidirectional Silence Detection Enable Example

H.323 VoIP Call Preservation for All Calls Example

The following configuration example enables H.323 VoIP call preservation for all calls:

voice service voip

 h323

  call preserve 

H.323 VoIP Call Preservation for a Dial Peer Example

The following configuration example enables H.323 VoIP call preservation for one dial peer:

voice class h323 4

 call preserve 

dial-peer voice 1

 voice class h323 4

H.323 Call Preservation for RTP and RTCP and Silence Detection Example

The following configuration example enables H.323 VoIP call preservation and limits RTP and RTCP inactivity detection and bidirectional silence detection (if configured) to H.323 VoIP preserved calls only:

voice service voip

 h323

  call preserve limit-media-detection

RTP and RTCP Inactivity Detection Configuration Example

The following configuration example can be used to enable RTP and RTCP inactivity detection for dial peers. Note that for call preservation VAD must be set to off (no vad command):

dial-peer voice 10 voip

 no vad

gateway

 timer receive-rtcp 4

ip rtcp report-interval 60

Bidirectional Silence Detection Enable Example

The following configuration example enables bidirectional silence detection:

gateway

 timer media-inactive 5

ip rtcp report interval

Additional References

The following sections provide references related to Call Preservation for H.323 VoIP Calls.

Related Documents

Related Topic	Document Title
Cisco CallManager	Cisco CallManager Documentation
Cisco SRST	Cisco SRST Documentation
Syslog	Syslog Documentation

Standards

Standard	Title
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.	—

MIBs

MIB	MIBs Link
Cisco SRST SNMP MIB	To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs

RFCs

RFC	Title
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature.	—

Technical Assistance

Description	Link
The Cisco Technical Support & Documentation website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.	http://www.cisco.com/techsupport

Command Reference

This section documents new commands only.

call preserve

To enable the preservation of H.323 VoIP calls, use the call preserve command in h323, voice-class h323, and voice service voip configuration modes. To reset to the default, use the no form of this command.

call preserve [limit-media-detection]

no call preserve [limit-media-detection]

Syntax Description

limit-media-detection

Limits RTP and RTCP inactivity detection and bidirectional silence detection (if configured) to H.323 VoIP preserved calls only.

Command Default

H.323 VoIP call preservation is disabled.

Command Modes

h323, voice-class h323, or voice service voip

Command History

Cisco IOS Release	Version	Modification
12.4(4)XC	Cisco SRST 4.0	This command was introduced.

Usage Guidelines

The call preserve command activates H.323 VoIP call preservation for following types of failures and connections:

Failure Types

•WAN failures that include WAN links flapping or degraded WAN links

•Cisco CallManager software failure, such as when the ccm.exe service crashes on a Cisco CallManager server.

•LAN connectivity failure, except when a failure occurs at the local branch

Connection Types

•Calls between two Cisco CallManager controlled endpoints

–During Cisco CallManager reloads

–When a Transmission Control Protocol (TCP) connection between one or both endpoints and Cisco CallManager used for signaling H.225.0 or H.245 messages is lost or flapping

–Between endpoints that are registered to different Cisco CallManagers in a cluster and the TCP connection between the two Cisco CallManagers is lost

–Between IP phones and the PSTN at the same site

•Calls between Cisco IOS gateway and an endpoint controlled by a softswitch where the signaling (H.225.0, H.245 or both) flows between the gateway and the softswitch and media flows between the gateway and the endpoint.

–When the softswitch reloads.

–When the H.225.0 or H.245 TCP connection between the gateway and the softswitch is lost, and the softswitch does not clear the call on the endpoint

–When the H.225.0 or H.245 TCP connection between softswitch and the endpoint is lost, and the soft-switch does not clear the call on the gateway

•Call flows that involve a Cisco IP in IP (IPIP) gateway running in media flow-around mode that reload or lose connection with the rest of the network

When bidirectional silence and RTP and RTCP inactivity detection are configured, they are enabled for all calls by default. To enable them for H.323 VoIP preserved calls only, you must use the call preserve command's limit-media-detection keyword.

H.323 VoIP call preservation can be applied globally to all calls and to a dial peer.

Examples

The following example enables H.323 VoIP call preservation for all calls.

voice service voip

 h323

  call preserve 

The following configuration example enables H.323 VoIP call preservation for dial peer 1.

voice-class h323 4 

 call preserve

dial-peer voice 1 voip

 voice-class h323 4 

The following example enables H.323 VoIP call preservation and enables RTP and RTCP inactivity detection and bidirectional silence detection for preserved calls only:

voice service voip

 h323

  call preserve limit-media-detection

The following example enables RTP and RTCP inactivity detection. Note that for H.323 VoIP call preservation VAD must be set to off (no vad command).

dial-peer voice 10 voip

 no vad

gateway

 timer receive-rtcp

ip rtcp report-interval

The following configuration example enables bidirectional silence detection:

gateway

 timer media-inactive

ip rtcp report interval

Related Commands

Command	Description
h323	Enables the H.323 voice service configuration commands.
show h323 calls preserved	Displays data about active H.323 VoIP preserved calls.
voice-class h323	Assigns an H.323 voice class to a VoIP dial peer.
voice service voip	Enters voice-service configuration mode

show h323 calls preserved

To display data about active H.323 VoIP preserved calls, use the show h323 calls preserved command in user EXEC or privileged EXEC mode.

show h323 calls preserved

Command Modes

User EXEC
Privileged EXEC

Command History

Cisco IOS Release	Version	Modification
12.4(4)XC	Cisco SRST 4.0	This command was introduced.

Usage Guidelines

The show h323 calls preserved command displays data per preserved call. Only active calls are displayed; preserved call history is not.

If translation rules are configured, the value displayed in the "Calling Number" field may have been translated by a gateway. Gateways handle called number values as the numbers to which calls are routed.

The "CallID" field displays the shorter form of the 16-octet, globally-unique connection ID that is allocated for each call leg. The show call active voice brief command also displays a shorter form of the CallID value (part of the third octet and the fourth octet). The longer form of the CallID value is output by the show call active voice command.

The CallID value can be used to refer to a call leg associated with the CallID when issuing other voice commands on the gateway, such as the show voice call status command and the clear call voice command.

An output value of -1 displayed in the "H225 FD" or "H245 FD" field denotes that the call was preserved due to an error detected on the H.225.0 connection. The actual H.225.0 socket file descriptor used for this call can be found from the syslog message that was output when this call was preserved.

To obtain more information about a call, you can also use the show call active voice command. Calls can be cleared with the clear call voice causecode command.

Examples

The following is sample output from the show h323 calls preserved command where one active call is preserved:

Router# show h323 calls preserved

CallID = 11EC , Calling Number = , Called Number = 3210000 , 
RemoteSignallingIPAddress=9.13.0.26 , RemoteSignallingPort=49760 , 
RemoteMediaIPAddress=9.13.0.11 , RemoteMediaPort=17910 , Preserved Duration = 262 , Total 
Duration = 562 , H225 FD = -1 , H245 FD = -1

Table 1 provides an alphabetical listing of the fields displayed in the output of the show h323 calls preserved command and a description of each field.

Table 1 show h323 calls preserved Field Descriptions

Field	Description
Called Number	The phone number entered by the caller.
CallID	The shortened name for connection ID displayed in the show call active voice brief command.
H225 FD	The file descriptor number of the H.225.0 TCP socket.
H245 FD	The file descriptor number of the H.245 TCP socket.
Preserved Duration	The time in seconds that the call has been preserved.
RemoteMediaIPAddress	The remote media IP address.
RemoteMediaPort	The remote media IP address.
RemoteSignallingIPAddress	The remote signaling IP address.
RemoteSignallingPort	The remote signaling port.
Total Duration	The time in seconds of the phone call.

Related Commands

Command	Description
call preserve	Enables the preservation of H.323 VoIP calls.
clear call voice	Clears one or more voice calls detected as inactive because there is no RTP or RTCP activity.
show call active voice	Displays call information for voice calls in progress.
show voice call	Displays the call status for voice ports on the Cisco router.

Open Source License Acknowledgements

The following notices pertain to this software license.

OpenSSL/Open SSL Project

This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/).

This product includes cryptographic software written by Eric Young (eay@cryptsoft.com).

This product includes software written by Tim Hudson (tjh@cryptsoft.com).

License Issues

The OpenSSL toolkit stays under a dual license, i.e. both the conditions of the OpenSSL License and the original SSLeay license apply to the toolkit. See below for the actual license texts. Actually both licenses are BSD-style Open Source licenses. In case of any license issues related to OpenSSL please contact openssl-core@openssl.org.

OpenSSL License:

Copyright © 1998-2007 The OpenSSL Project. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions, and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. All advertising materials mentioning features or use of this software must display the following acknowledgment: "This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/)".

4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to endorse or promote products derived from this software without prior written permission. For written permission, please contact openssl-core@openssl.org.

5. Products derived from this software may not be called "OpenSSL" nor may "OpenSSL" appear in their names without prior written permission of the OpenSSL Project.

6. Redistributions of any form whatsoever must retain the following acknowledgment:

"This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (http://www.openssl.org/)".

THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT "AS IS"' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

This product includes cryptographic software written by Eric Young (eay@cryptsoft.com). This product includes software written by Tim Hudson (tjh@cryptsoft.com).

Original SSLeay License:

Copyright © 1995-1998 Eric Young (eay@cryptsoft.com). All rights reserved.

This package is an SSL implementation written by Eric Young (eay@cryptsoft.com).

The implementation was written so as to conform with Netscapes SSL.

This library is free for commercial and non-commercial use as long as the following conditions are adhered to. The following conditions apply to all code found in this distribution, be it the RC4, RSA, lhash, DES, etc., code; not just the SSL code. The SSL documentation included with this distribution is covered by the same copyright terms except that the holder is Tim Hudson (tjh@cryptsoft.com).

Copyright remains Eric Young's, and as such any Copyright notices in the code are not to be removed. If this package is used in a product, Eric Young should be given attribution as the author of the parts of the library used. This can be in the form of a textual message at program startup or in documentation (online or textual) provided with the package.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. All advertising materials mentioning features or use of this software must display the following acknowledgement:

"This product includes cryptographic software written by Eric Young (eay@cryptsoft.com)".

The word `cryptographic' can be left out if the routines from the library being used are not cryptography-related.

4. If you include any Windows specific code (or a derivative thereof) from the apps directory (application code) you must include an acknowledgement: "This product includes software written by Tim Hudson (tjh@cryptsoft.com)".

THIS SOFTWARE IS PROVIDED BY ERIC YOUNG "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The license and distribution terms for any publicly available version or derivative of this code cannot be changed. i.e. this code cannot simply be copied and put under another distribution license [including the GNU Public License].

Glossary

See Internetworking Terms and Acronyms.

© 2005 Cisco Systems, Inc. All rights reserved.