Table Of Contents
G.722-64 and iLBC Codec Support on Cisco Unified Border Elements, DSP Farms, and Voice Gateways
How to Configure G.722-64 and iLBC Codecs for Voice Gateways
Conferencing and Transcoding Session Capacities
How to Configure G.722-64 and iLBC Codecs for Cisco Unified Border Elements
Feature Information for G.722-64 and iLBC Codec Support on Cisco UBEs, DSP Farms, and Voice Gateways
G.722-64 and iLBC Codec Support on Cisco Unified Border Elements, DSP Farms, and Voice Gateways
First Published: December 17, 2007Last Updated: December 27, 2007The G.722-64 and iLBC codecs are supported for Cisco Unified Border Elements (Cisco UBEs), DSP farms, and voice gateways. Conferencing and universal transcoding are supported on both codecs.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for G.722-64 and iLBC Codec Support on Cisco UBEs, DSP Farms, and Voice Gateways" section.
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
•How to Configure G.722-64 and iLBC Codecs for Voice Gateways
•How to Configure G.722-64 and iLBC Codecs for Cisco Unified Border Elements
•Feature Information for G.722-64 and iLBC Codec Support on Cisco UBEs, DSP Farms, and Voice Gateways
How to Configure G.722-64 and iLBC Codecs for Voice Gateways
The G.722-64 and iLBC codecs can be used to enable conferencing and transcoding on Cisco IOS voice gateways in a Cisco Unified Communications Manager network. Digital signal processor (DSP) farms provide conferencing and transcoding services using DSP resources on high-density digital voice/fax network modules.
To configure conferencing and transcoding for voice gateway routers, see the "Configuring Enhanced Conferencing and Transcoding for Voice Gateway Routers" chapter of the Cisco CallManager and Cisco IOS Interoperability Guide.
For more information on configuring iLBC codecs for H.323 and SIP, see the "Dial Peer Overview" chapter and "Dial Peer Features and Configuration" chapter in Dial Peer Configuration on Voice Gateway Routers
The following changes apply to this chapter:
Codecs
End-user devices must be equipped with one of the following codecs:
Codec Packetization Periods for Transcoding (ms)G.711 a-law, G.711 u-law, G.722-64
10, 20, or 30
G.729, G.729A, G.729B, G.729AB
10, 20, 30, 40, 50, or 60
iLBC
20 or 30
Conferencing and Transcoding Session Capacities
Each DSP is individually configurable to support either conferencing or transcoding and standard voice termination. The total number of conferencing, transcoding, and voice termination sessions is limited by the capacity of the entire system, which includes the DSPs, hardware platform, physical voice interface, and Cisco Unified Communications Manager.
Table 1 and Table 2 list the maximum number of conference calls and transcoding sessions that DSPs can handle, in theory. Actual capacity may be less based on the total system design.
How to Configure G.722-64 and iLBC Codecs for Cisco Unified Border Elements
The G.722-64 and iLBC codecs can be used to set up transcoding on Cisco Unified Border Elements (Cisco UBEs). To configure these codecs on a Cisco UBE, see the "Fundamental Cisco Multiservice IP-to-IP Gateway Configuration" chapter of the Cisco Multiservice IP-to-IP Gateway document.
Additional References
The following sections provide references related to G.722-64 and iLBC Codec Support on Cisco UBEs, DSP farms, and voice gateways.
Related Documents
Related Topic Document TitleConferencing and transcoding for voice gateways
Cisco Communications Manager and Cisco IOS Interoperability Guide
Transcoding for Cisco Unified Communications Manager Express
Cisco Unified Communications Manager Express System Administrator Guide
Transcoding for Cisco Unified Border Elements
Dial-peer configuration
Standards
MIBs
RFCs
RFC TitleRFC3951
Internet Low Bit Rate Codec (iLBC)
RFC3952
Real-time Transport Protocol (RTP) Payload Format for internet Low Bit Rate Codec (iLBC) Speech
Technical Assistance
Command Reference
This section documents new and modified commands:
codec (dial-peer)
To specify the voice coder rate of speech for a dial peer, use the codec command in dial-peer configuration mode. To reset the default value, use the no form of this command.
Cisco 1750 and Cisco 1751 Modular Access Routers, Cisco AS5300 and AS5800 Universal Access Servers, and Cisco MC3810 Multiservice Concentrators
codec codec [bytes payload_size]
no codec codec [bytes payload_size]
Cisco 2600 and 3600 Series Routers and Cisco 7200 and 7500 Series Routers
codec {codec [bytes payload_size] | transparent}
no codec {codec [bytes payload_size] | transparent}
Syntax Description
codec
Codec options available for the various platforms are described in Table 3, below.
bytes
(Optional) Specifies the number of bytes in the voice payload of each frame.
payload-size
(Optional) Number of bytes in the voice payload of each frame. See Table 4 for valid entries and default values.
transparent
Enables codec capabilities to be passed transparently between endpoints in a Cisco Unified Border Element.
Note The transparent keyword is only available on the Cisco 2600 and 3600 Series Router and Cisco 7200 and 7500 Series Router platforms.
Defaults
g729r8, 30-byte payload for VoFR and VoATM
g729r8, 20-byte payload for VoIP
See Table 4 for valid entries and default values.Command Modes
dial-peer configuration
Command History
Usage Guidelines
Use this command to define a specific voice coder rate of speech and payload size for a VoIP or VoFR dial peer. This command is also used for VoATM.
A specific codec type can be configured on the dial peer as long as it is supported by the setting used with the codec complexity voice-card configuration command. The codec complexity command is voice-card specific and platform specific. The codec complexity voice-card configuration command is set to either high or medium.
If the codec complexity command is set to high, the following keywords are available: g711alaw, g711ulaw, g722-64, g723ar53, g723ar63, g723r53, g723r63, g726r16, g726r24, g726r32, g728, g729r8, and g729br8.
If the codec complexity command is set to medium, the following keywords are available: g711alaw, g711ulaw, g726r16, g726r24, g726r32, g729r8, and g729br8.
The codec dial-peer configuration command is particularly useful when you must change to a small-bandwidth codec. Large-bandwidth codecs, such as G.711, do not fit in a small-bandwidth link. However, the g711alaw and g711ulaw codecs provide higher quality voice transmission than other codecs. The g729r8 codec provides near-toll quality with considerable bandwidth savings.
If codec values for the dial peers of a connection do not match, the call fails.
You can change the payload of each VoIP frame by using the bytes keyword; you can change the payload of each VoFR frame by using the bytes keyword with the payload-size argument. However, increasing the payload size can add processing delay for each voice packet.
Table 4 describes the voice payload options and default values for the codecs and packet voice protocols.
For toll quality, use the g711alaw or g711ulaw keyword. These values provide high-quality voice transmission but use a significant amount of bandwidth. For nearly toll quality (and a significant savings in bandwidth), use the g729r8 keyword.
Note The clear-channel keyword is not supported on Cisco AS5300.
Note The G.723 and G.728 codecs are not supported on the 1700 platform for Cisco Hoot and Holler applications.
Note The transparent keyword affects only H.323 to H.323 connections.
Note The G.722-64 codec is only supported for H.323 and SIP.
Examples
The following example shows how to configure a voice coder rate that provides toll quality voice with a payload of 120 bytes per voice frame on a router that is acting as a terminating node. The sample configuration begins in global configuration mode and is for VoFR dial peer 200.
dial-peer voice 200 vofrcodec g711ulaw bytes 240The following example configures a voice coder rate for VoIP dial peer 10 that provides toll quality but uses a relatively high amount of bandwidth:
dial-peer voice 10 voipcodec g711alawThe following example configures the transparent codec used by the Cisco Unified Border Element:
dial-peer voice 1 voipincoming called-number .Tdestination-pattern .Tsession target rascodec transparentRelated Commands
codec (DSP Farm profile)
To specify the codecs supported by a digital signal processor (DSP) farm profile, use the codec command in DSP farm profile configuration mode. To remove the codec, use the no form of this command.
codec {codec-type | pass-through}
no codec {codec-type | pass-through}
Syntax Description
Command Default
Transcoding
•g711alaw
•g711ulaw
•g729abr8
•g729ar8
Conferencing
•g711alaw
•g711ulaw
•g729abr8
•g729ar8
•g729br8
•g729r8
MTP
•g711ulaw
Command Modes
DSP farm profile configuration
Command History
Release Modification12.3(8)T
This command was introduced.
12.4(4)T
The pass-through keyword was added.
12.4(15)XY
The g722-64 keyword was added.
Usage Guidelines
Only one codec is supported for each Media Termination Point (MTP) profile. To support multiple codecs, you must define a separate MTP profile for each codec.
Hardware MTPs support only G.711 a-law and G.711 u-law. If you configure a profile as a hardware MTP, and you want to change the codec to other than G.711, you must first remove the hardware MTP by using the no maximum sessions hardware command.
The pass-through keyword is supported for transcoding and MTP profiles only; it is not supported for conferencing profiles. To support the RSVP agent on a SCCP device, you must use the codec pass-through command. In pass-through mode, the SCCP device processes the media stream using a pure software MTP regardless of the nature of the stream. This enables video and data streams to be processed in addition to audio. When pass-through mode is set in a transcoding profile, no transcoding is done for the session; the transcoding device performs a pure software MTP function. Pass-through mode can be used for Secure RTP sessions.
Examples
The following example shows the call density and codec complexity being set to GSMEFR:
Router(config)# dspfarm profile 123 transcodeRouter(config-dspfarm-profile)# codec gsmefr
Related Commands
codec preference
To specify a list of preferred codecs to use on a dial peer, use the codec preference command in voice-class configuration mode. To disable this functionality, use the no form of this command.
codec preference value codec-type [mode frame_size][bytes payload-size] [packetization-period 20] [encap rfc3267] [frame-format {bandwidth-efficient | octet-aligned [crc | no-crc]}] [modes modes-value]
no codec preference value codec-type
Syntax Description
Command Default
If the gsmamr-nb keyword is entered, the default values are as follows:
Packetization period is 20 ms.
Encap is rfc3267.
Frame format is octet-aligned.
CRC is no-crc.
Modes value is 0-7.Command Modes
Voice-class configuration
Command History
Usage Guidelines
The routers at opposite ends of the WAN may have to negotiate the codec selection for the network dial peers. The codec preference command specifies the order of preference for selecting a negotiated codec for the connection. Table 5 describes the voice payload options and default values for the codecs and packet voice protocols.
Note The transparent keyword not supported when the call start command is configured.
Examples
The following example sets the codec preference to the GSMAMR-NB codec and specifies parameters:
Router(config-voice-class)# codec preference 1 gsmamr-nb packetization-period 20 encap rfc3267 frame-format octet-aligned crcThe following example creates codec preference list 99 and applies it to dial peer 1919:
voice class codec 99codec preference 1 g711alawcodec preference 2 g711ulaw bytes 80codec preference 3 g723ar53codec preference 4 g723ar63 bytes 144codec preference 5 g723r53codec preference 6 g723r63 bytes 120codec preference 7 g726r16codec preference 8 g726r24codec preference 9 g726r32 bytes 80codec preference 10 g729br8codec preference 11 g729r8 bytes 50codec preference 12 gsmefrenddial-peer voice 1919 voipvoice-class codec 99The following example configures the transparent codec used by the Cisco Unified Border Element:
voice class codec 99codec preference 1 transparentcodec preference 1 transparent
Note You can only assign a preference value of 1 to the transparent codec. Additional codecs assigned to other preference values are ignored if the transparent codec is used.
The following example shows how to configure the iLBC codec used by the Cisco Unified Border Element:
voice class codec 99codec preference 1 ilbc 30 200Related Commands
Feature Information for G.722-64 and iLBC Codec Support on Cisco UBEs, DSP Farms, and Voice Gateways
Table 6 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. 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.
Note Table 6 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.
© 2007 Cisco Systems, Inc. All rights reserved.