Table Of Contents

Implementing SBC Interworking DTMF

Contents

Prerequisites for Implementing Interworking DTMF

Information About Interworking DTMF

How to Implement Interworking DTMF

Configuring DTMF for an H.323 Adjacency

Configuring DTMF for a SIP Adjacency

Configuration Example for Implementing Interworking DTMF

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Related Command Summary

Implementing SBC Interworking DTMF

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SBC enables interworking between in-channel RTP signaling using the audio/telephone-event MIME type (RFC 2833) to and from out-of-band signaling using the SIP INFO or H.245 UserInputIndication.method.

SBC automatically selects the best signaling technique based on the capabilities of the endpoints in a call. Dual-tone multifrequency (DTMF) Interworking is employed only if the caller and callee support non-overlapping DTMF event mechanisms (for example if the caller supports sending DTMF using the SIP INFO method only and the callee supports receiving DTMF only using in-channel RTP signaling).

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Note For a complete description of commands used in this chapter, refer to the Cisco IOS XR Session Border Controller Command Reference. To locate documentation for other commands that appear in this chapter, use the command reference master index, or search online.

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Feature History for Implementing SBC Transcoding

Release	Modification
Release 3.3.0	This feature was introduced on the Cisco XR 12000 Series Router.
Release 3.4.0	No modification.
Release 3.5.0	No modification.
Release 3.6.0	No modification.

Contents

•Prerequisites for Implementing Interworking DTMF

•Information About Interworking DTMF

•How to Implement Interworking DTMF

•Configuration Example for Implementing Interworking DTMF

•Additional References

•Related Command Summary

Prerequisites for Implementing Interworking DTMF

The following prerequisites are required to implement interworking DTMF:

•You must be in a user group associated with a task group that includes the proper task IDs for SBC commands being used. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

•You must install and activate the package installation envelope (PIE) for the SBC software.

For detailed information about PIE installation, refer to the Upgrading and Managing Cisco IOS XR Software module in the Cisco IOS XR Getting Started Guide.

•Before implementing interworking DTMF, the SBC must already be created. See the procedures described in the "SBC Configuration Prerequisites" module.

•Release 3.5.0 of SBC does not interwork RTP tones sent as part of the media-stream.

Information About Interworking DTMF

All adjacencies support passing DTMF as H.245 UserInputIndication (alphanumeric), or in-band. By default, H.323 negotiates support for RFC 2833 RTP Named Telephone Events (rtp-nte) with the signaling peer. Issuing the dtmf-relay command without the rtp-nte option disables rtp-nte support.

When a call is routed between two adjacencies, one of which is configured to support rtp-nte and one of which is not, then DTMF interworking is enabled. In DTMF interworking, H.245 UserInputIndications are converted to RFC 2833 packets and vice versa. When DTMF interworking is enabled for a call, the rtp-nte adjacency must be configured with the dynamic RTP payload type that the remote endpoint uses for RFC 2833.

The simplest configuration is to use the same RTP payload type value for all H.323 adjacencies. If H.323 adjacencies are configured with different values, the following requirements apply to all rtp-nte adjacencies:

•All endpoints on that adjacency that support RFC 2833 must use the same receive RTP dynamic payload type.

•This dynamic payload type must be configured on the adjacency in advance of call setup.

How to Implement Interworking DTMF

Redundancy configurations are described in the following sections:

•Configuring DTMF for an H.323 Adjacency

•Configuring DTMF for a SIP Adjacency

Configuring DTMF for an H.323 Adjacency

This task configures interworking DTMF for an H.323 adjacency. See the "Implementing SBC Adjacencies" module for more information on configuring adjacencies.

SUMMARY STEPS

1. configure

2. sbc service-name

3. sbe

4. adjacency h323 adjacency-name

DETAILED STEPS

	Command or Action	Purpose
Step 1	configure Example: RP/0/0/CPU0:router# configure	Enables global configuration mode.
Step 2	sbc service-name Example: RP/0/0/CPU0:router(config)# sbc mysbc	Enters the mode of an SBC service. Use the service-name argument to define the name of the service.
Step 3	sbe Example: RP/0/0/CPU0:router(config-sbc)# sbe	Enters the mode of an SBE entity within an SBC service.
Step 4	adjacency h323 adjacency-name Example: RP/0/0/CPU0:router(config-sbc-sbe)# adjacency h323 myh323adjacency	Enters the mode of an SBE H.323 adjacency. Use the adjacency-name argument to define the name of the service.

Configuring DTMF for a SIP Adjacency

No special configuration is needed to configure DTMF for a SIP adjacency. DTMF configuration is done transparently. See the "Implementing SBC Adjacencies" module for more information on configuring adjacencies.

Configuration Example for Implementing Interworking DTMF

This section provides an example of how to configure interworking DTMF. The example shows the complete configuration for an H.323 adjacency which includes interworking DTMF.

configure

sbc mysbc

sbe

adjacency h323 myh323adjacency

signaling-address ipv4 10.1.0.2

signaling-port 123

vrf vpn3

signaling-peer gk 10.10.10.10

signaling-peer-port 123

remote-address ipv4 1.2.3.0/24

dbe-location-id 1

alias foo

authentication endpoint

authentication-key FG56KJ

account isp42

media-bypass

dtmf-relay

rtp payload-type nte 111

description test adjacency

commit

attach

commit

show

sbc mysbc

sbe

adjacency h323 myh323adjacency

alias foo

vrf vpn3

authentication-key FG56KJ

signaling-address ipv4 10.1.0.2

signaling-port 123

remote-address ipv4 1.2.3.0/24

authentication endpoint

signaling-peer-port 123

dtmf-relay

description test h323adjacency

dbe-location-id 1

account isp42

media-bypass

rtp payload-type nte 111

!

!

!

Additional References

The following sections provide references related to implementing SBC interworking DTMF.

Related Documents

Related Topic	Document Title
Cisco IOS XR master command reference	Cisco IOS XR Master Commands List
Cisco IOS XR SBC interface configuration commands	Cisco IOS XR Session Border Controller Command Reference
Initial system bootup and configuration information for a router using the Cisco IOS XR Software	Cisco IOS XR Getting Started Guide
Cisco IOS XR command modes	Cisco IOS XR Command Mode Reference
Cisco MGX 8880 documentation	http://www.cisco.com/en/US/products/hw/gatecont/ps3869/index.html

Standards

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

MIBs

MIBs	MIBs Link
—	To locate and download MIBs using Cisco IOS XR software, use the Cisco MIB Locator found at the following URL and choose a platform under the Cisco Access Products menu: http://cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml

RFCs

RFCs	Title
RFC 2833	RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals

Technical Assistance

Description	Link
The Cisco Technical Support 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

Related Command Summary

This section provides an alphabetical list of the commands related to Interworking DTMF configuration on the Cisco XR 12000 Series Router. For more information about the commands, see the Cisco IOS XR Session Border Controller Command Reference.

Command	Purpose
adjacency h323 adjacency-name	Enters the mode of an SBE H.323 adjacency.
dtmf-relay [rtp-nte]	Configures DTMF relay for an H.323 adjacency.
rtp payload-type nte number	Configures the dynamic RTP payload type for RFC 2833 Named Telephone Event (rtp-nte) packets when doing DTMF interworking on an H.323 adjacency.