14-Voice Command

Table of Contents

Chapter 1 VoIP Configuration Commands. 1-1

1.1 VoIP Configuration Commands. 1-1

1.1.1 address. 1-1

1.1.2 area. 1-2

1.1.3 area-id (voice entity view) 1-3

1.1.4 busytone-t-th. 1-3

1.1.5 caller-permit 1-4

1.1.6 cid display. 1-6

1.1.7 cid enable. 1-7

1.1.8 cid send. 1-7

1.1.9 cid type. 1-8

1.1.10 cng-on. 1-9

1.1.11 compression. 1-10

1.1.12 cptone. 1-16

1.1.13 debugging voice cm.. 1-19

1.1.14 debugging voice data-flow. 1-20

1.1.15 debugging voice dpl 1-20

1.1.16 debugging voice h225. 1-21

1.1.17 debugging voice h245. 1-21

1.1.18 debugging voice ipp. 1-22

1.1.19 debugging voice rcv 1-23

1.1.20 debugging voice vas. 1-23

1.1.21 debugging voice vmib. 1-24

1.1.22 debugging voice vpp. 1-25

1.1.23 default entity compression. 1-26

1.1.24 default entity normal-connect slow-h245. 1-27

1.1.25 default entity payload-size. 1-27

1.1.26 default entity service data enable. 1-28

1.1.27 default entity service data payload-size. 1-29

1.1.28 default entity vad-on. 1-30

1.1.29 delay. 1-30

1.1.30 delay-reversal 1-31

1.1.31 description (voice entity view) 1-32

1.1.32 description (voice subscriber line view) 1-32

1.1.33 dial-prefix. 1-33

1.1.34 dial-program.. 1-35

1.1.35 display voice call-history-record. 1-35

1.1.36 display voice call-info. 1-37

1.1.37 display voice default 1-38

1.1.38 display voice entity. 1-40

1.1.39 display voice ipp. 1-41

1.1.40 display voice number-substitute. 1-43

1.1.41 display voice rcv ccb. 1-43

1.1.42 display voice rcv statistic. 1-46

1.1.43 display voice subscriber-line. 1-48

1.1.44 display voice voip data-statistic. 1-50

1.1.45 display voice vpp. 1-52

1.1.46 dot-match. 1-55

1.1.47 dtmf sensitivity-level 1-56

1.1.48 dscp media. 1-57

1.1.49 dtmf threshold. 1-57

1.1.50 echo-canceller 1-62

1.1.51 em-phy-parm.. 1-63

1.1.52 em-signal 1-64

1.1.53 entity. 1-65

1.1.54 fast-connect 1-66

1.1.55 first-rule. 1-67

1.1.56 fxo-monitoring. 1-68

1.1.57 hookoff-time. 1-68

1.1.58 impedance. 1-69

1.1.59 line. 1-70

1.1.60 match-template. 1-71

1.1.61 max-call (voice dial program view) 1-73

1.1.62 max-call (voice entity view) 1-74

1.1.63 normal-connect slow-h245. 1-75

1.1.64 number-match. 1-76

1.1.65 number-substitute. 1-77

1.1.66 open-trunk. 1-77

1.1.67 outband. 1-78

1.1.68 overlap timer 1-80

1.1.69 overlap voip h323. 1-80

1.1.70 payload-size. 1-81

1.1.71 plc-mode. 1-83

1.1.72 priority. 1-83

1.1.73 private-line. 1-84

1.1.74 progress-tone. 1-85

1.1.75 receive gain. 1-86

1.1.76 reset voice call-history-record all 1-87

1.1.77 reset voice ipp. 1-87

1.1.78 reset voice rcv 1-88

1.1.79 reset voice vpp. 1-88

1.1.80 reset voice voip data-statistic. 1-89

1.1.81 rtp payload-type nte. 1-89

1.1.82 rule. 1-90

1.1.83 select-rule rule-order 1-93

1.1.84 select-rule search-stop. 1-95

1.1.85 select-rule type-first 1-96

1.1.86 select-stop. 1-97

1.1.87 send-busytone. 1-97

1.1.88 send-number (voice entity view) 1-98

1.1.89 send-number (voice subscriber line view) 1-99

1.1.90 send-ring. 1-100

1.1.91 service data enable. 1-101

1.1.92 shutdown (voice entity view) 1-101

1.1.93 shutdown (voice subscriber line view) 1-102

1.1.94 silence-th-span. 1-103

1.1.95 special-service. 1-103

1.1.96 subscriber-line. 1-104

1.1.97 substitute (voice subscriber line view, VoIP entity view, VoFR entity view) 1-105

1.1.98 substitute (voice dial program view, POTS entity view) 1-106

1.1.99 terminator 1-107

1.1.100 timer dial-interval 1-108

1.1.101 timer first-dial 1-109

1.1.102 timer ring-back. 1-109

1.1.103 timer wait-digit 1-110

1.1.104 trace interval 1-111

1.1.105 transmit gain. 1-111

1.1.106 tunnel-on. 1-112

1.1.107 type. 1-113

1.1.108 vad-on. 1-114

1.1.109 vi-card busy-tone-detect 1-115

1.1.110 vi-card cptone-custom.. 1-116

1.1.111 vi-card reboot 1-118

1.1.112 voice-setup. 1-118

1.1.113 voip calledtunnel 1-119

1.1.114 voip call-start 1-120

1.1.115 voip h323-descriptor 1-121

1.1.116 voip timer 1-121

1.1.117 vqa data-statistic. 1-122

1.1.118 vqa dscp. 1-123

1.1.119 vqa dsp-monitor 1-124

1.1.120 vqa jitter-buffer mode. 1-125

1.1.121 vqa performance. 1-126

Chapter 2 BSV Configuration Commands. 2-1

2.1.1 permanent-active. 2-1

2.1.2 power-source. 2-1

Chapter 3 VoFR Configuration Commands. 3-1

3.1 VoFR Configuration Commands. 3-1

3.1.1 address. 3-1

3.1.2 call-mode. 3-2

3.1.3 cid select-mode. 3-3

3.1.4 debugging voice vofr 3-3

3.1.5 display fr vofr-info. 3-4

3.1.6 display voice vofr call 3-5

3.1.7 display voice vofr statistic. 3-8

3.1.8 motorola base-svc. 3-9

3.1.9 motorola encapsulation. 3-10

3.1.10 motorola max-voice. 3-10

3.1.11 motorola remote-id. 3-11

3.1.12 outband vofr 3-12

3.1.13 priority. 3-12

3.1.14 send-called-number 3-13

3.1.15 seq-number 3-14

3.1.16 timestamp. 3-15

3.1.17 trunk-id. 3-15

3.1.18 vad-on. 3-16

3.1.19 vofr 3-17

3.1.20 vofr frf11-timer 3-18

3.1.21 vofr jitter-buffer 3-19

3.1.22 voice bandwidth. 3-19

Chapter 4 E1/T1 Voice Configuration Commands. 4-1

4.1 E1/T1 Voice Configuration Commands. 4-1

4.1.1 ani 4-1

4.1.2 ani-offset 4-2

4.1.3 answer 4-2

4.1.4 cas. 4-3

4.1.5 clear-forward-ack. 4-4

4.1.6 debugging voice r2. 4-5

4.1.7 debugging voice rcv r2. 4-6

4.1.8 debugging voice vpp r2. 4-6

4.1.9 default 4-7

4.1.10 delay. 4-8

4.1.11 display voice em call-statistics. 4-10

4.1.12 display voice em ccb. 4-12

4.1.13 display voice r2 call-statistics. 4-14

4.1.14 display voice rcv statistic r2. 4-16

4.1.15 display voice subscriber-line. 4-17

4.1.16 display voice voip. 4-19

4.1.17 dl-bits. 4-21

4.1.18 dtmf 4-22

4.1.19 effect-time. 4-23

4.1.20 final-callednum.. 4-23

4.1.21 force-metering. 4-24

4.1.22 group-b. 4-25

4.1.23 line. 4-25

4.1.24 loopback. 4-26

4.1.25 mfc (R2 CAS) 4-27

4.1.26 mode. 4-28

4.1.27 open-trunk. 4-29

4.1.28 pcm.. 4-30

4.1.29 pri-set 4-31

4.1.30 re-answer 4-33

4.1.31 register-number 4-33

4.1.32 register-value. 4-34

4.1.33 renew. 4-37

4.1.34 reset voice em.. 4-39

4.1.35 reset voice r2. 4-39

4.1.36 reverse. 4-40

4.1.37 seizure-ack. 4-40

4.1.38 select-mode. 4-41

4.1.39 send-dialtone. 4-42

4.1.40 sendring. 4-43

4.1.41 signal-value. 4-44

4.1.42 special-character 4-45

4.1.43 subscriber-line. 4-45

4.1.44 timer (digital E&M) 4-46

4.1.45 timer dtmf (R2) 4-47

4.1.46 timer register-pulse (R2) 4-48

4.1.47 timer register-complete (R2) 4-49

4.1.48 timer ring (R2) 4-49

4.1.49 timer dl (R2) 4-50

4.1.50 timeslot-set (CE1/PRI) 4-51

4.1.51 timeslot-set (CT1) 4-53

4.1.52 trunk-direction. 4-55

4.1.53 ts. 4-56

Chapter 5 Fax Configuration Commands. 5-1

5.1 Fax Configuration Commands. 5-1

5.1.1 cngced-detection. 5-1

5.1.2 debugging voice fax. 5-2

5.1.3 default entity fax. 5-3

5.1.4 default entity modem compatible-param.. 5-5

5.1.5 default entity modem protocol 5-6

5.1.6 display voice fax. 5-7

5.1.7 fax baudrate. 5-9

5.1.8 fax ecm.. 5-10

5.1.9 fax level 5-11

5.1.10 fax nsf-on. 5-12

5.1.11 fax protocol 5-13

5.1.12 fax support-mode. 5-14

5.1.13 fax train-mode. 5-15

5.1.14 modem compatible-param.. 5-16

5.1.15 modem protocol 5-17

5.1.16 reset voice fax statistics. 5-18

5.1.17 reset voice fax trans-statistics. 5-18

5.1.18 voip h323-conf tcs-t38. 5-19

Chapter 6 Voice RADIUS Configuration Commands. 6-1

6.1 Voice RADIUS Configuration Commands. 6-1

6.1.1 aaa-client 6-1

6.1.2 authentication. 6-1

6.1.3 authentication-did. 6-2

6.1.4 callednumber receive-method. 6-3

6.1.5 card-digit 6-4

6.1.6 cdr 6-4

6.1.7 delay receive-dial 6-6

6.1.8 debugging voice vcc. 6-6

6.1.9 display aaa unsent-h323-call-record. 6-8

6.1.10 display voice aaa-client configuration. 6-9

6.1.11 display voice call-history-record. 6-10

6.1.12 display voice vcc. 6-13

6.1.13 gw-access-number 6-16

6.1.14 password-digit 6-17

6.1.15 process-config. 6-18

6.1.16 redialtimes. 6-19

6.1.17 reset voice vcc. 6-21

6.1.18 select-language. 6-21

Chapter 7 GK Client Configuration Commands. 7-1

7.1 GK Client Configuration commands. 7-1

7.1.1 area-id (in Voice GK Client View) 7-1

7.1.2 debugging voice ras. 7-2

7.1.3 display voice gateway. 7-2

7.1.4 gk-client 7-3

7.1.5 gk-2nd-id. 7-4

7.1.6 gk-id. 7-5

7.1.7 gk-security call 7-5

7.1.8 gk-security register-pwd. 7-6

7.1.9 gw-address. 7-7

7.1.10 gw-id. 7-8

7.1.11 ras-on. 7-8

Chapter 8 SIP Client Commands. 8-1

8.1 SIP Client Commands. 8-1

8.1.1 address sip. 8-1

8.1.2 debugging voice sip. 8-2

8.1.3 display voice sip call-statistics. 8-3

8.1.4 display voice sip register status. 8-4

8.1.5 local-host 8-5

8.1.6 proxy. 8-5

8.1.7 register-enable. 8-6

8.1.8 registrar 8-7

8.1.9 reset voice sip. 8-8

8.1.10 sip. 8-8

8.1.11 sip-call forwarding. 8-9

8.1.12 sip-comp. 8-9

8.1.13 sip-comp agent 8-10

8.1.14 sip-domain. 8-11

8.1.15 source-ip. 8-12

8.1.16 user 8-12

 


Chapter 1  VoIP Configuration Commands

1.1  VoIP Configuration Commands

1.1.1  address

Syntax

address { ip ip-address | ras }

undo address { ip | ras }

View

Voice entity view

Parameter

ip ip-address: Indicate a VoIP dial entity session destination, i.e. the called IP address.

ras: Router uses RAS recommendation to interact information with GK Server to map the called phone number to the IP address of peer voice gateway. It is used only in the networking configuration that uses GK (gatekeeper) to provide voice IP services.

Description

Use the address command to configure the voice routing policy to the peer voice gateway.

Use the undo address command to cancel the voice routing policy that has been configured.

By default, no routing policy is configured.

This command is used to configure the network address for the VolP voice entity. The system supports the following two VolP routing policies at present.

l           Static routing policy: Find the IP address of destination voice gateway in static mode according to address ip ip-address command.

l           Dynamic routing policy: The router and GK Server interact with RAS information after the address ras command is configured. GK will dynamically send back the peer voice gateway address that matches the called number to the router.

Related command: address sip, match-template.

Example

# Configure the destination IP address corresponding to the called 12345 as 10.1.1.2.

[H3C-voice-dial-entity1] match-template 12345

[H3C-voice-dial-entity1] address ip 10.1.1.2

1.1.2  area

Syntax

area { north-america | custom | europe }

undo area

View

Voice subscriber-line view

Parameter

north-america: Busy tone type of the switch connected to this subscriber line is of North America standard.

custom: Busy tone type of the switch connected to this subscriber line is defined by the users.

europe: Busy tone type of the switch connected to this subscriber line is of Europe standard.

Description

Use the area command to configure the type of busy tone detection for FXO voice subscriber line.

Use the undo area command to restore the default value.

By default, europe busy tone type standard is set.

This command is used only for 2-wire loop trunk subscriber line FXO, and it can only perform configuration to the first voice subscriber line on the voice card. If successful, the configuration will be effective for all the voice subscriber lines of the voice card.

When this subscriber line is connected to a common user line of a program-controlled switch, if the user on the switch side hooks on first, only by detecting the busy tone can the router know the user on-hooking operation. Since different switches execute different prompt tone schemes, there exist different frequency spectrum characteristics. This command is used to set the frequency spectrum characteristic used by the router to detect the existence of the busy tone.

Example

# Use north-america standard to detect the existence of the busy tone on voice subscriber-line 0/0/1.

[H3C-voice-line0/0/1] area north-america

1.1.3  area-id (voice entity view)

Syntax

area-id string

undo area-id

View

Voice entity view

Parameter

string: Area ID, an integer in the range of 0 to 9. The “#” can be used.

Description

Use the area-id command to configure the area ID of voice GW.

Use the undo area-id command to cancel the specified area ID.

By default, no area ID of voice GW is configured.

The voice area ID is set in VoIP voice entity view and will be automatically added to the beginning of called numbers when establishing calls.

Related command: match-template, entity.

Example

# Configure the VoIP voice entity 101 with the area ID 6#.

[H3C-voice-dial-entity101] area-id 6#

1.1.4  busytone-t-th

Syntax

busytone-t-th time-threshold

undo busytone-t-th

View

FXO voice subscriber line view

Parameter

time-threshold: Threshold of busy tone detection. It ranges from 2 to 12, with a bigger value meaning longer detection time. The threshold defaults to 2, that is, the device hangs up upon two contiguous detections of busy tone.

Description

Use the busytone-t-th command to configure the threshold of busy tone detection.

Use the undo busytone-t-th command to restore the default.

The actual busy tone data does not always match the configured parameter. If the difference is large, detection inaccuracy may occur, resulting in on-hook failure or improper on-hook. You can however, tune the threshold of busy tone detection to achieve detection accuracy. For example, you can eliminate improper on-hooks caused by busy tone data inaccuracy by increasing the time for busy tone detection.

Note that before you configure a threshold of busy tone detection, you must test it fully making sure that on-hook operation can be done properly.

Example

# Set the threshold of busy tone detection to 3.

[H3C-voice-line0/0/1] busytone-t-th 3

1.1.5  caller-permit

Syntax

caller-permit calling-string

undo caller-permit { calling-string | all }

View

Voice entity view

Parameter

all: All callers.

calling-string: Calling numbers that are permitted to call in, in the format of { [ + ] string [ $ ]| $ }. The largest length of the string is 31. The symbols are described in the following:

l           +: Appears at the beginning of a calling number to indicate that the number is E.164-compliant.

l           $: As the last character to indicate the end of the number. That means the entire calling number must match all the characters before “$” in the string. If there is only “$” in the string, the calling number can be empty.

l           string: A string composed of any characters of “0123456789ABCD#*.!+%[]()-”. The meanings of the characters are described in the following table:

Table 1-1 Meanings of the characters in string

Character

Meaning

0-9

Numbers from 0 to 9. Each means a digit.

ABCD

Each character means a digit.

# and *

Each means a valid digit.

.

A wildcard. It can match any digit of a valid number. For example, 555. . . . matches any string that begins with 555 and with four additional characters.

!

The character or characters right in front of it does not appear or appears once. For example, 56!1234 can match 51234 and 561234.

+

The character or characters right in front of it appears once or several times. But its appearance at the beginning of the whole number means the number is E.164-compliant.

-

Hyphen. It connects two values (the smaller one before it and the bigger one after it) to indicate a range. For example, “1-9” means numbers from 1 to 9 (inclusive).

%

The character or characters right in front of it does not appear, or appears once or several times.

[ ]

Selects one character from the group. For example, [1-36A] can match only one character among 1, 2, 3, 6, and A.

( )

A group of characters. For example, (123A) means a string “123A”. It is usually used with “!”, “%”, and “+”. For example, “408(12)+” can match 40812 or 408121212. But it cannot match 408. That is, “12” can appear continuously and it must at least appear once.

 

&  Note:

l      The character or characters in front of "!”, “%”, and “+” are not to be matched accurately. They are handled similar to the wildcard “.”. Moreover, these symbols cannot be used alone. There must be a valid digit or digits in front of them.

l      If you want to use “[ ]” and “( )” at the same time, you must use them in the format “( [ ] )”. Other formats, such as “[ [ ] ]” and “[ ( ) ]” are illegal.

l      “-“ can only be used inside “[ ]”, and it only connects the same type of characters, such as “0-9”. The formats like “0-A” are illegal.

 

Description

Use the caller-permit command to configure the calling numbers that are permitted to call in.

Use the undo caller-permit command to delete the calling numbers that are permitted to call in.

By default, no calling number is configured. That means there is no limitation on calling numbers.

You can configure 32 calling numbers for a voice entity at most. If you only use “$”, empty calling numbers are permitted to call in.

Related command: match-template.

Example

# Configure voice entity 2 to permit 660268 or empty calling numbers to call in.

[H3C-voice-dial-entity2] caller-permit 660268$

[H3C-voice-dial-entity2] caller-permit $

# Configure voice entity 2 to permit the calling numbers beginning with 20 to call in.

[H3C-voice-dial-entity2] caller-permit 20

1.1.6  cid display

Syntax

cid display

undo cid display

View

Voice subscriber line view

Parameter

None

Description

Use the cid display command to enable caller identification display.

Use the undo cid display command to disable caller identification display.

By default, caller identification display is enabled.

This command is applicable to FXS subscriber lines.

When functioning as the called, the FXS module can send caller identification information to its called phone between the first and second rings. When disabled to send caller identification information, the FXS interface sends the character “P” received from the IP side instead. Thus, the called phone is unable to display caller identification information.

Example

# Enable caller identification display on voice subscriber line 1/0/0.

[H3C-voice-line1/0/0] cid display

1.1.7  cid enable

Syntax

cid enable

undo cid enable

View

Voice subscriber line view

Parameter

None

Description

Use the cid enable command to enable CID on the FXO interface.

Use the undo cid enable command to disable CID on the FXO interface.

By default, CID is enabled on the FXO interface.

This command applies to FXO voice subscriber lines only.

With CID enabled, the FXO interface can receive the modulated caller identification data from an analog line between the first ring and second rings and then send the data demodulated with FSK to the IP side.

With CID disabled, the local FXO interface does the following when the calling party sends a calling number:

l           If a number is configured in the match template for the POTS entity associated with the local FXO interface, the interface substitutes this number for the calling number and sends it to the called side.

l           If wildcard dots (.) are used in the number configured in the match template for the POTS entity associated with the local FXO interface, the interface substitutes zeros for the calling number’s digits in the place of dots, for example, 1000 for 1… and then sends the substitution number to the called side.

Example

# Enable CID on FXO voice subscriber line 1/0/0.

[H3C-voice-line1/0/0] cid enable

1.1.8  cid send

Syntax

cid send

undo cid send

View

Voice subscriber line view

Parameter

None

Description

Use the cid send command to enable the FXO or FXS module to send calling numbers to the IP side.

Use the undo cid send command to disable the FXO or FXS module to send calling numbers to the IP side.

By default, calling numbers are sent to the IP side.

This command applies to FXS and FXO subscriber lines only.

After you configure the undo cid send command, the FXO interface does not send any number to the called side, regardless of whether the calling party has sent a calling number and regardless of whether a number is configured in the match template for the voice entity associated with the FXO interface.

Example

# Enable the FXO voice subscriber line 3/0/0 to send calling numbers to the IP side.

[H3C-voice-line3/0/0] cid send

# Disable the FXS voice subscriber line 1/0/0 to send calling numbers to the IP side.

[H3C-voice-line1/0/0] undo cid send

1.1.9  cid type

Syntax

cid type { complex | simple }

View

Voice subscriber line view

Parameter

complex: Caller identification information is transmitted in multiple-data message format (MDMF).

simple: Caller identification information is transmitted in single-data message format (SDMF).

Description

Use the cid type command to configure the format of transmitted information about the calling party.

Two formats are available: multiple data message format (MDMF) and single data message format (SDMF). When the remote end supports one format only, you must use the same setting at the local end.

This command applies to both FXO and FXS subscriber lines.

Example

# Set the format of the transmitted caller identification information to SDMF on voice subscriber line 1/0/0.

[H3C-voice-line1/0/0] cid type simple

1.1.10  cng-on

Syntax

cng-on

undo cng-on

View

Voice subscriber line view

Parameter

None

Description

Use the cng-on command to enable comfort noise function.

Use the undo cng-on command to disable the comfort noise function,.

By default, comfort noise setting is enabled.

This command is applicable to FXO, FXS, E&M subscriber lines and digital E1 voice subscriber line. When the silence detecting function on a corresponding voice entity is enabled, some background noise can be generated by using the command to fill the toneless intervals during a conversation. If no comfort noise is generated, the toneless intervals during a conversation will cause the interlocutors uncomfortable.

Related command: subscriber-line and vad-on.

Example

# Disable comfort noise function on subscriber line 1/0/0.

[H3C-voice-line1/0/0] undo cng-on

1.1.11  compression

Syntax

compression { 1st-level | 2nd-level | 3rd-level | 4th-level } { g711alaw | g711ulaw | g723r53 | g723r63 | g729a | g729ab | g729r8 | g729br8 | g726r16 | g726r24 | g726r32 | g726r40 | clear-channel }

undo compression { 1st-level | 2nd-level | 3rd-level | 4th-level }

View

Voice entity view

Parameter

1st-level: Indicates the first selected voice compression method.

2nd-level: Indicates the second selected voice compression method.

3rd-level: Indicates the third selected voice compression method.

4th-level: Indicates the fourth selected voice compression method.

g711alaw: Specifies G.711 A-law codec (defining the pulse code modulation technology), requiring the bandwidth of 64 kbps, usually adopted by Europe.

g711ulaw: Specifies G.711μ-law codec, requiring the bandwidth of 64 kbps, usually adopted in the North America and Japan.

g723r53: Specifies G.723.1 Annex A codec, requiring the bandwidth of 5.3 kbps.

g723r63: Specifies G.723.1 Annex A codec, requiring the bandwidth of 6.3 kbps.

g729a: Specifies G.729 Annex A codec (a simplified version of G.729 codec), requiring the bandwidth of 8 kbps.

g729r8: Specifies G.729 (the voice coding technology using conjugate algebraic-code-excited linear-prediction) codec, requiring the bandwidth of 8 kbps.

g729ab: Adds G.729 Annex B codec on the basis of G.729a.

g729br8: Specifies G.729 Annex B codec, requiring the bandwidth of 8 kbps. This codec supports voice activity detection (VAD), discontinuous transmission (DTX), and comfort noise (CNG).

g726r16: Specifies G.726 Annex A codec. It uses the adaptive differential pulse code modulation (ADPCM) technology, requiring the bandwidth of 16 kbps.

g726r24: Specifies G.726 Annex A codec. It uses ADPCM, requiring the bandwidth of 24 kbps.

g726r32: Specifies G.726 Annex A codec. It uses ADPCM, requiring the bandwidth of 32 kbps.

g726r40: Specifies G.726 Annex A codec. It uses ADPCM, requiring the bandwidth of 40 kbps.

clear-channel: Specifies the G.Clear codec, which is used for transparent data transmission with a bandwidth of 64 Kbps (nodata compression).

Description

Use the compression command to configure the voice codec according to priority level.

Use the undo compression command to restore the default value.

By default, g729r8 codec is set.

g711alaw and g711ulaw coding provide high-quality voice transmission, while requiring greater bandwidth.

g726r16, g726r24, g726r32, and g726r40 are widely adopted now for voice coding. They use the ADPCM technology and provide multiple bandwidth options.

g723r53 and g723r63 coding provide silence suppression technology and comfort noise, the relatively higher speed output is based on multi-pulse multi-quantitative level technology and provides relatively higher voice quality to certain extent, and the relatively lower speed output is based on the Algebraic-Code-Excited Linear-Prediction technology and provides greater flexibility for application.

The voice quality provided by the g729r8 and g729a codec is similar to the ADPCM of 32 kbps, having the quality of a toll, and also featuring low bandwidth, lesser event delay and medium processing complexity, hence it has a wide field of application.<