Vocoder Entry

Description:

Each VoIP Bearer port can have up to seven individual Codecs configured under it. Once created under the IP Bearer Profiles object, the IMG’s IP signaling stacks will negotiate their use in the order in which they appear in the GUI. The order which the vocoders are negotiated can be modified by selecting one of the vocoder entries and using the Up/Down arrows in the ClientView menu toolbar. The Codec Entry Pane specifies a payload type such as G.729A etc. Maximum, Minimum, and Preferred payload types can be changed through the drop down menu.

 

Note: To enable certain vocoders verify the host flag line in the dhcpd.conf file has the correct value set. See Setting Host Flag topic. Additionally, a valid license for AMR and EVRC must be installed.

 

Accessing this Pane

Dialogic IMG EMS > IP Bearer Profiles > IP Bearer Profile > Supported Vocoders

 

Maximum Objects

Up to seven Codec entries per IP Bearer Profile.

 

Related Topics

VoIP Overview

Configuring IP Bearer Profiles

Setting Host Flags

Codec/Payload Selection

SIP Codec Negotiation Priority selection

 

 

Click on the Technical Notes link for more information on the Vocoder Entry pane.

 

ClientView Pane:

sc_vocoder_entry_1053.png

 

Field Descriptions:

Entry ID:

This field is automatically populated with the next available ID and specifies the ID of the Codec. To change the ID, click in the Entry ID field and select a different ID from the drop down menu. Up to seven entries can be added to each Bearer Profile object and the ID's range in value from 0-6.

Note: The Entry ID field does not control the priority with which the codecs are selected. The priority is determined by where in the WebUI tree the codec is positioned. The Codec at the top of the list gets highest priority and the priority gets lower as you go down the list. The priority can be changed by clicking on the Codec and pressing the Up/Down arrows in the menu bar to move the Codec either up or down the list.

 

Payload Type:

Select from drop down menu from a list of all the payload types supported by the IMG. Below is a list of the supported Codecs and their payload sizes.

Payload Type

Preferred Payload Size

Minimum Payload Size

Maximum Payload Size

AMR (SIP ONLY)

20 ms

20 ms

20 ms

EVRC (SIP ONLY)

20 ms

20 ms

20 ms

G.711 alaw

20 ms

10 ms

30 ms

G.711 ulaw

20 ms

10 ms

30 ms

G.723 5.3 kbps

30 ms

30 ms

90 ms

G.723 6.3 kbps

30 ms

30 ms

90 ms

G.729A, G.729A/B

20 ms

10 ms

60 ms

G.729E, G.729E/G

20 ms

10 ms

30 ms

iLBC 20 ms

20 ms

20 ms

20 ms

iLBC 30 ms

30 ms

30 ms

30 ms

GSM-FR Static Payload Type

20 ms

20 ms

60 ms

GSM-FR Dynamic Payload Type

20 ms

20 ms

60 ms

G.726-32/G.721 Static Payload Type

20 ms

10 ms

60 ms

G.726-32/G.721 Dynamic Payload Type

20 ms

10 ms

60 ms

Clear Channel Codec

20 ms

10 ms

30 ms

 

 

Preferred Payload Size (ms):

The Preferred Payload Size field specifies the desired payload size for the selected Payload Type. The preferred payload size can be changed by using the drop down menu in that field. See Codec/Payload Selection and SIP Codec Negotiation Priority selection in the Related Topics section above for more information on Codec/Payload Size Negotiation

 

Minimum Payload Size (ms):

The Minimum Payload Size field specifies the minimum payload size for the selected Payload Type. The minimum payload size can be changed by using the drop down menu in that field. See Codec/Payload Selection and SIP Codec Negotiation Priority selection in the Related Topics section above for more information on Codec/Payload Size Negotiation

 

Maximum Payload Size (ms):

The Maximum Payload Size field specifies the maximum payload size for the selected Payload Type. The maximum payload size can be changed by using the drop down menu in that field. See Codec/Payload Selection and SIP Codec Negotiation Priority selection in the Related Topics section above for more information on Codec/Payload Size Negotiation

 

Default Payload Type:

If the payload type is static then it must be used. If the payload type is dynamic then it is selectable in ClientView. Below are the Codecs that currently support a dynamic payload type.

CODEC

Payload Type

AMR

96-127 (Default=97)

EVRC

96-127 (Default=98)

iLBC 20 ms

96-127 (Default=96)

iLBC 30 ms

96-127 (Default=96)

G.729E, G.729E/G

96-127 (Default=108)

G726-32/G.721 Dynamic Payload Type

96-127 (Default=98)

GSM-FR Dynamic Payload Type

96-127 (Default=96)

Clear Channel Codec

96-127 (Default=125)

 

 

Annex B Support: (G.729A and G.729E only)

Annex B Support selection in this menu only applies to how the SIP SDP will use the “annexb=” string during codec negotiation.  This is a SIP-specific parameter.  By the RFC standards 3555/4856, “annexb=” can be used for G.729A and G.729E vocoders to negotiate silence suppression usage (see the following table for all negotiation scenarios), but at the RTP media level “Annex B” defines the silence suppression algorithm for G.729A (hence G.729A/B) while “Annex G” defines the silence suppression algorithm for G.729E (hence G.729E/G).

In this drop down menu, the user can decide how the SIP/SDP “annexb=” string will be utilized. The selections are Annex B=No, Annex B=Yes. This option is currently supported only in G.729A and G.729E, when SIP is the IP signaling protocol. When configuring the G.729A or G.729E codec in ClientView the Annex B field is defaulted to Yes. See Below for more information.

 

Annex B Ingress: (10.5.3 SP4)

When configuring G.729A or G.729E codec the manner in which the Annex B Parameter is handled has been redesigned to allow for many different Annex B negotiation behaviors. Starting in software version 10.5.3 SP4 a field labeled Annex B Ingress was added to allow for the selection of several possible behaviors. When G.729A or G.729E is selected, the Annex B and Annex B Ingress field will be opened. Use the table below to select how SDP negotiation will behave.

 

Note: Annex B Ingress is for incoming call with G.729 or G.729E only.

 

sc_f5502_annexb_support.png

 

Table below displays all possible combinations of Annex B support.

Case #

IMG Configuration

Annex-B in Inbound call IMG Response
Annex-B Support Annex-B Ingress
1 Yes Disabled (Default) Yes Respond with Yes
2 Yes Disabled (Default) No Respond with no a-line
3 Yes Disabled (Default) No a-line Respond with no a-line
4 No Disabled (Default) Yes Reject Call with 488
5 No Disabled (Default) No Respond with No
6 No Disabled (Default) No a-line Respond with No
7 Yes Reject Call, if different Yes Respond with Yes
8 Yes Reject Call, if different No Reject Call with 488
9 Yes Reject Call, if different No a-line Respond with no a-line
10 No Reject Call, if different Yes Respond with 488
11 No Reject Call, if different No Respond with No
12 No Reject Call, if different No a-line Reject Call with 488
13 Yes Echo Received Yes Respond with Yes
14 Yes Echo Received No Respond with No
15 Yes Echo Received No a-line Respond with no a-line
16 No Echo Received Yes Respond with Yes
17 No Echo Received No Respond with No
18 No Echo Received No a-line Respond with no a-line
19 Yes Send Configured Yes Respond with Yes
20 Yes Send Configured No Respond with Yes
21 Yes Send Configured No a-line Respond with Yes
22 No Send Configured Yes Respond with No
23 No Send Configured No Respond with No
24 No Send Configured No a-line Respond with No