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Enhanced Clear Channel Codec Support

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Cisco PGW 2200 Softswitch Enhanced Clear Channel Codec Support Feature Module

Feature Description

Feature Overview

Benefits

Prerequisites

Restrictions or Limitations

Related Documents

Supported Standards, MIBs, and RFCs

XECfgParm.dat Configuration Tasks

Configuring the XECfgParm.dat File for This Feature

Configuration Examples

Provisioning Tasks

Method 1: Checking the Clear Channel Codec in the SDP of the First Incoming SIP INVITE Message

Method 2: Checking the Request Line in the First Incoming SIP INVITE Message

Observing the First SIP INVITE Message from the SIP Peer

Enabling the Request Line Check

Matching the tgrp and the trunk-context Parameter Values

Provisioning Examples

Software Changes for This Feature

Properties

New Properties

Modified Properties

Result Types

Troubleshooting the Feature

Obtaining Documentation and Submitting a Service Request

Glossary


Cisco PGW 2200 Softswitch Enhanced Clear Channel Codec Support Feature Module

Document Release History

Publication Date
Comments

June 2009

Initial release of document


Feature History

Release
Modification

9.8(1)

The Enhanced Clear Channel Codec Support feature is introduced on the Cisco PGW 2200 Softswitch.


This document describes the Enhanced Clear Channel Codec Support feature and includes the following sections:

•Feature Description

•XECfgParm.dat Configuration Tasks

•Provisioning Tasks

•Provisioning Examples

•Software Changes for This Feature

•Troubleshooting the Feature

•Obtaining Documentation and Submitting a Service Request

•Glossary

Feature Description

Feature Overview

The clear channel codec guarantees bit integrity of a digital signal 0 (DS-0) transferred through a gateway. It supports the transporting of nonvoice circuit data sessions through a VoIP network. It enables the VoIP networks to transport data calls.

Before the introduction of this feature, the Cisco PGW 2200 Softswitch supported the clear channel codec for TDM-to-SIP data calls. That is, the Cisco PGW 2200 Softswitch could handle data calls that originated from the TDM side and ended on the Session Initiation Protocol (SIP) side.

The Enhanced Clear Channel Codec Support feature completes clear channel codec support to SIP-to-TDM data calls. Based on incoming SIP messages and user configurations, the Cisco PGW 2200 Softswitch sends certain clear channel codecs to gateways and sets the transmission medium requirement (TMR) value for data calls properly. With this feature, users can make TDM data calls through the SIP network. In addition, users can customize clear channel codecs that media gateways use for data calls.

Figure 1 shows a typical deployment for this feature. In this deployment, users can initiate data calls of all directions from the PSTN network to the SIP network, and vice versa. For example, users can make SIP-to-TDM and TDM-to-SIP data calls.

Figure 1 Typical Deployment for This Feature

Benefits

This feature provides the following benefits:

•Handles SIP-to-TDM data calls—Users can make end-to-end data calls that come from CUCM-connected end-devices or gateways via SIP trunks to a TDM destination end point.

•Supports various representations of clear channel codecs—Users can customize clear channel codecs that they want gateways to use.

•Manipulates the TMR value—Users can set the TMR value on SIP trunk groups, in domain profiles, or in dial plans to influence the TMR value being delivered to the TDM side. For example, users can set the TMR value on a SIP trunk group to specify that all of the calls originating on this trunk group are data calls. Users can also overwrite or change the TMR value for a call during the number analysis.

Prerequisites

The Cisco PGW 2200 Softswitch must be running software Release 9.8(1). Prerequisites for this release can be found in the Release Notes for the Cisco PGW 2200 Softswitch Release 9.8(1) at

http://www.cisco.com/en/US/docs/voice_ip_comm/pgw/9/release/note/rn981.html

Restrictions or Limitations

The Enhanced Clear Channel Codec Support feature has one limitation. If you provision both the DEFAULT_TMR result type, and the MGCPDIALPKG result type, you must provision the DEFAULT_TMR result type before the MGCPDIALPKG result type.

Related Documents

This document contains information that is strictly related to this feature. The documents that contain additional information related to the Cisco PGW 2200 Softswitch are at

http://www.cisco.com/en/US/products/hw/vcallcon/ps2027/tsd_products_support_series_home.html

Supported Standards, MIBs, and RFCs

No new or modified standards, MIBs, or RFCs are supported by this feature.

XECfgParm.dat Configuration Tasks

Configuring the XECfgParm.dat File for This Feature

To use this feature, you must first configure the GWClearChannelAlgorithm parameter of the XECfgParm.dat file.

Specify a clear channel codec or multiple clear channel codecs that you want gateways to use for data calls in the GWClearChannelAlgorithm parameter. The valid values for this parameter are a clear channel codec name, or clear channel codec names, with consecutive names being separated by a semicolon. The default value is NULL.

•If the GWClearChannelAlgorithm is set to NULL, you disable clear channel codec support on the Cisco PGW 2200 Softswitch. Incoming data calls are cleared with the cause that bearer capability is not available.

•If the GWClearChannelAlgorithm contains a codec name, the call continues. The Cisco PGW 2200 Softswitch sends the codec name to the media gateway for data calls. The media gateway switches to this codec.

•If the GWClearChannelAlgorithm contains multiple codec names (separated by semicolons), the Cisco PGW 2200 Softswitch sends all of them to the media gateway for data calls. The media gateway chooses the one it prefers.

Note For details on the GWClearChannelAlgorithm parameter, see Appendix A, "XECfgParm.dat File Parameters", in the Cisco PGW 2200 Softswitch Release 9.8 Software Installation and Configuration Guide.

Configuration Examples

Here is an example of the command you enter to configure the GWClearChannelAlgorithm parameter in the XECfgParm.dat file: 

*.GWClearChannelAlgorithm = X-CCD;CLEARMODE;CCD;G.nX64;G.Clear # clear channel algorithm

Note Any changes of the XECfgParm.dat file require a restart of the Cisco PGW 2200 Softswitch software.

Provisioning Tasks

This section describes provisioning tasks for this feature.

Note Make sure you have finished the configuration before you perform provisioning tasks for this feature. See the "XECfgParm.dat Configuration Tasks" section.

In this feature, the Cisco PGW 2200 Softswitch handles SIP-to-TDM data calls in two steps:

1. The Cisco PGW 2200 Softswitch first concludes whether a SIP-to-TDM call is a data call.

2. If the call is a data call, the Cisco PGW 2200 Softswitch then sets the TMR value for that data call.

In the provisioning of this feature, you must tell the Cisco PGW 2200 Softswitch how to conclude whether a SIP-to-TDM call is a data call. You can choose either of the following two methods. No other provisioning tasks are required for this feature.

•Method 1: Checking the Clear Channel Codec in the SDP of the First Incoming SIP INVITE Message

•Method 2: Checking the Request Line in the First Incoming SIP INVITE Message

Note If you want to use Method 2, make sure that the SIP peer puts the clear channel codec information in the tgrp and the trunk-context parameters of the first outgoing SIP INVITE message. For example, the CUCM puts clear channel codec information in the tgrp and the trunk-context parameters of the first outgoing SIP INVITE message, you can use Method 2 when the Cisco PGW 2200 Softswitch is connected to CUCM. We recommend that you use Method 2 if the SIP peer puts the clear channel codec information in the tgrp and the trunk-context parameters of the first outgoing INVITE message.

For provisioning samples, see the "Provisioning Examples" section.

Method 1: Checking the Clear Channel Codec in the SDP of the First Incoming SIP INVITE Message

The Cisco PGW 2200 Softswitch checks the clear channel codec in the SDP of the first incoming SIP INVITE message to conclude whether the SIP-to-TDM call is a data call.

If one of the codecs in the SDP matches any codec configured in the GWClearChannelAlgorithm parameter of the XECfgParms.dat file, the Cisco PGW 2200 Softswitch concludes that the call is a SIP-to-TDM data call.

Set the CheckClearChannelCodecInSDP property to 1 to enable the clear channel codec check in the SDP of the first incoming SIP INVITE message.

prov-ed:profile:name="sipprf",checkclearchannelcodecinsdp="1"

Method 2: Checking the Request Line in the First Incoming SIP INVITE Message

The Cisco PGW 2200 Softswitch checks the request line of the first incoming SIP INVITE message to conclude whether the SIP-to-TDM call is a data call.

If the following two requirements are met, the Cisco PGW 2200 Softswitch concludes that this call is a SIP-to-TDM data call:

•The tgrp parameter value matches the SipTgrpLabel property value.

•The trunk-context parameter value matches the SipTrunkContext property value.

Perform the following tasks to use this method:

•Observing the First SIP INVITE Message from the SIP Peer

•Enabling the Request Line Check

•Matching the tgrp and the trunk-context Parameter Values

Observing the First SIP INVITE Message from the SIP Peer

Observe the first incoming SIP INVITE message from the SIP peer. Method 2 is applicable when the first SIP INVITE message from the SIP peer contains clear channel codec information in the tgrp and the trunk-context parameters of the request line.

Here is a sample of the first incoming SIP INVITE message. Notice that the tgrp parameter value and the trunk-context parameter value are in bold. Write down the two parameter values. You are going to use them later. 

INVITE sip:3333;phone-context=abcd.com;tgrp=ccdata; 
trunk-context=abcd.com@1.98.98.119:5060; transport=tcp;user=phone SIP/2.0

Date: Fri, 25 Jul 2008 18:57:16 GMT

Call-Info: <sip:1.98.98.115:5060>;method="NOTIFY;Event=telephone-event;Duration=500"

Allow: INVITE, OPTIONS, INFO, BYE, CANCEL, ACK, PRACK, UPDATE, REFER, SUBSCRIBE, NOTIFY

From: <sip:4444@1.98.98.115>;tag=ef18c435-bc4f-454b-b8e8-d747acdaf9c7-19431898

Allow-Events: presence, kpml

P-Asserted-Identity: <sip:4444@1.98.98.115>

Supported: 100rel,timer,resource-priority,replaces

Min-SE:  1800

Remote-Party-ID: <sip:4444@1.98.98.115>;party=calling;screen=yes;privacy=off

User-Agent: Cisco-CUCM7.0

To: <sip:3333@1.98.98.119>

Contact: <sip:4444@1.98.98.115:5060;transport=tcp>

Expires: 180

Call-ID: 7e6d5380-88a1220c-1-73626201@1.98.98.115^M

Via: SIP/2.0/TCP 1.98.98.115:5060;branch=z9hG4bK046fface8

CSeq: 101 INVITE

Session-Expires:  1800

Max-Forwards: 70

Content-Length: 122

v=0

o=Cisco 633 8080 IN IP4 10.0.246.220

s=SIP Call

c=IN IP4 10.0.246.220

t=0 0 

m=audio 5000 RTP/AVP 125 100 

a=rtpmap:125 G.nX64/8000 

a=rtpmap:100 X-NSE/8000 

a=fmtp:100 200-202 

a=X-sqn:0 

a=X-cap: 1 audio RTP/AVP 100 

a=X-cpar: a=rtpmap:100 X-NSE/8000 

a=X-cpar: a=fmtp:100 200-202 

a=X-cap: 2 image udptl t38

Enabling the Request Line Check

Set the CheckSipTgrpParam property to 1 to enable the request line check of the first incoming SIP INVITE message. 

prov-ed:profile:name="sipprf",checksiptgrpparam="1"

Matching the tgrp and the trunk-context Parameter Values

Set the SipTgrpLabel and the SipTrunkContext properties to the parameter values you wrote down previously in the "Observing the First SIP INVITE Message from the SIP Peer" section.

Set the SipTgrpLabel property to the tgrp parameter value. Set the SipTrunkContext property to the trunk-context parameter value. 

prov-ed:profile:name="sipprf",siptgrplabel="ccdata"

prov-ed:profile:name="sipprf",siptrunkcontext="abcd.com"

Provisioning Examples

This section provides a provisioning example for this feature. Additional provisioning examples for the Cisco PGW 2200 Softswitch can be found in the Cisco PGW 2200 Softswitch Release 9.8 Provisioning Guide. 


Method 1—Clear Channel Codec Check in the SDP of the First Incoming SIP INVITE Message

________________________________________

; Add a SIP Profile

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

prov-add:profile:name="sipprf",type="sipprofile",trustlevel="1"


________________________________________

; Enable the Clear Channel Codec Check in the SDP

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

prov-ed:profile:name="sipprf",checkclearchannelcodecinsdp="1"

or


Method 2—Request Line Check in the First Incoming SIP INVITE Message

________________________________________

; Add a SIP Profile

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

prov-add:profile:name="sipprf",type="sipprofile",trustlevel="1"


________________________________________

; Enable the Request Line Check in the First Incoming SIP INVITE Message

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

prov-ed:profile:name="sipprf",checksiptgrpparam="1"


________________________________________

; Match the tgrp and the trunk-context Parameter Values

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

prov-ed:profile:name="sipprf",siptgrplabel="ccdata"

prov-ed:profile:name="sipprf",siptrunkcontext="abcd.com"

Software Changes for This Feature

The following sections contain software changes for this feature:

•Properties

•Result Types

Properties

This section describes new and modified properties introduced for this feature. For more information on other properties for Cisco PGW 2200 Softswitch, see the Cisco PGW 2200 Softswitch Release 9.8 Provisioning Guide.

New Properties

Table 1 describes the new properties for this feature.

Table 1 New Properties 

Property
Description

CheckClearChannelCodecInSDP

Use this property to control whether the Cisco PGW 2200 Softswitch checks the clear channel codec in the SDP of the first incoming SIP INVITE message to conclude that a call is a data call. This property is provisioned in SIP profiles.

Valid values: boolean.

0 = no clear channel codec check in the SDP.

1 = performs the clear channel codec check in the SDP.

Default value: 0.

Dynamically reconfigurable: yes.

CheckSipTgrpParam

Use this property to control whether the Cisco PGW 2200 Softswitch checks the tgrp parameter in the request line of the first incoming SIP INVITE message to conclude that a call is a data call. This property is provisioned in SIP profiles.

Valid values: boolean.

0 = does not check the tgrp parameter in the request line.

1 = checks the tgrp parameter in the request line.

Default value: 0.

Dynamically reconfigurable: yes.

SipTgrpLabel

Use this property to specify the clear channel routing class in SIP signaling. When you set the CheckSipTgrpParam property to 1, the value of the tgrp parameter in the first incoming SIP INVITE message must match this property value. This property is provisioned in SIP profiles.

Valid values: string (1 to 64 bytes string) or NULL (does not check the tgrp parameter).

Default value: ccdata.

Dynamically reconfigurable: yes.

SipTrunkContext

Use this property to specify a namespace on the trunk group. When you set the CheckSipTgrpParam property to 1, the value of the trunk-context parameter in the first incoming SIP INVITE message must match this property value. This property is provisioned in SIP profiles.

Valid values: string (1 to 64 bytes) or NULL (does not check the trunk-context parameter).

Default value: NULL.

Dynamically reconfigurable: yes.


Modified Properties

Table 2 describes the modified properties for this feature.

Table 2 Modified Properties 

Property
Description

DefaultTmr

Use this property to set the TMR value on a SIP sigpath. This SIP sigpath property is extended to trunk groups.

Valid values:

•SPEECH—Set TMR to SPEECH.

•UNRES_64K—Set TMR to UNRES_64K.

•AUDIO_3K—Set TMR to AUDIO_3K.

Default: SPEECH.

Dynamically Reconfigurable: yes.


Result Types

This section describes the new result type for this feature. For information on other result types, see the Cisco PGW 2200 Softswitch Release 9.8 Dial Plan Guide. Table 3 describes the new result type for this feature.

Table 3 New Result Type Definitions 

Result Number
Result Type
Dataword1
Dataword2
Dataword3
Dataword4
Analysis Points
Result Type Valid For
Intermediate
End Point
A-digit analysis
B-digit analysis
Cause
Pre-analysis

87

DEFAULT_TMR

Specifies the default TMR value

0 (not used)

0 (not used)

0 (not used)

 X

 

 X

 X

   

DEFAULT_TMR

A new result type DEFAULT_TMR is added for this feature. It allows the Cisco PGW 2200 Softswitch to set or overwrite the TMR value.

Dataword1 specifies the TMR value for this call:

•1—Set the TMR value to SPEECH.

•2—Set the TMR value to UNRES_64K.

•3—Set the TMR value to AUDIO_3K.

In the following example, you overwrite the TMR value for all of the calls whose calling numbers start with 400. The TMR values for these calls are set to unrestricted 64k (UNRES_64K). 

numan-add:resultset:custgrpid="1111",name="sip-tmr"

numan-add:resulttable:custgrpid="1111",resulttype="DEFAULT_TMR",dw1="2",setname="sip-tmr",
name="tmrdata"

numan-add:adigtree:custgrpid="1111",callside="originating",setname="sip-tmr",digitstring="
400"

Troubleshooting the Feature

The section describes two troubleshooting situations for this feature:

•A SIP-to-TDM data call cannot be established. (The data call fails, or turns into a voice call.)

 
Action
Description

Step 1 

Check the SDP of the first incoming SIP INVITE message.

Make sure the SDP of the first incoming SIP INVITE message contains clear channel codec information. If the SDP does not contain such information, check configurations of the SIP peer.

Step 2 

Check the outgoing Media Gateway Control Protocol (MGCP) message during the call setup.

Make sure local connection options (LCO) parameters of the outgoing create connection (CRCX) message contain clear channel codec information. If LCO parameters contain correct clear channel codec information, proceed to Step 4. Otherwise, proceed to Step 3.

Step 3 

Check the GWClearChannelAlgorithm parameter in the XECfgParm.dat file.

Make sure you have configured the GWClearChannelAlgorithm parameter to tell the Cisco PGW 2200 Softswitch clear channel codecs that you want media gateways to use for data calls.

See the "XECfgParm.dat Configuration Tasks" section.

Step 4 

Make sure you have enabled one of the two data call check methods.

Make sure you have configured either of the two methods for letting the Cisco PGW 2200 Softswitch conclude that a call is a data call:

•Check the clear channel codec in the SDP of the first incoming SIP INVITE message.

•Check the request line in the first incoming SIP INVITE message.

Note If you use the second method, make sure the tgrp parameter value matches the SipTgrpLabel property value, and the trunk-context parameter value matches the SipTrunkContext property value.

See the "Provisioning Tasks" section.

•The TDM side rejects a SIP-to-TDM data call.

 
Action
Description

Step 1 

Check the outgoing MGCP message during the call setup.

Make sure the TMR value in the outgoing MGCP message is acceptable on the TDM side. If the TMR value is not acceptable on the TDM side, proceed to Step 2.

Step 2 

Check the DEFAULT_TMR result type provisioned in the dial plan.

If the DEFAULT_TMR result type is provisioned, make sure the TMR value in Dataword1 of the result type is acceptable on the TDM side. If the TMR value is not acceptable, proceed to Step 3.

Step 3 

Check the default TMR value provisioned in the SIP profile of the incoming SIP trunk group.

Make sure the default TMR value is acceptable on the TDM side.

Obtaining Documentation and Submitting a Service Request

For information on obtaining documentation, submitting a service request, and gathering additional information, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:

http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html

Subscribe to the What's New in Cisco Product Documentation as a Really Simple Syndication (RSS) feed and set content to be delivered directly to your desktop using a reader application. The RSS feeds are a free service and Cisco currently supports RSS Version 2.0.

Glossary

Table 4 Acronym Expansions 

Acronym
Expansion

CRCX

create connection (message)

CUCM

Cisco Unified Communications Manager (formerly known as Cisco Unified CallManager)

DS-0

digital signal 0

LCO

local connection options

MGCP

Media Gateway Control Protocol

PGW

PSTN Gateway

SIP

Session Initiation Protocol

TMR

transmission medium requirement


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