The ISDN D-Channel carries control and signaling information needed to connect or disconnect calls and to negotiate special calling parameters in an ISDN network. The ISDN D-Channel object configures a D-Channel along with a set of D-Channel attributes onto a specific DS-1/Span and DS-0/Channel. To create the D-Channel object, right click on the ISDN D-Channels object and select ISDN D-Channel. See below for more information on configuring the ISDN D-Channel object.
Web GUI Page
Dialogic > IMG 2020 > Signaling > ISDN > New ISDN D Channel (T1 D-Channel object pane displayed below)
Maximum Objects
T1 - Up to 84 D-Channels, one for each T1 DS-1.
E1 – Up to 63 D-Channels, one for each E1 DS-1.
Related Topics and Dependencies
ISDN - Signaling
Configure ISDN
Field Descriptions
Primary Span
This field is a drop down menu that contains all the spans configured. Select from the menu which span the D-Channel will get configured on.
Primary Channel
Select from drop down menu which Channel the D-Channel will get configured on.
Secondary Span (T1 Only)
Select from drop down menu which Channel the D-Channel will get configured on. Supported in T1 only.
Secondary Channel (NFAS Only)
If configuring a secondary D-Channel select which channel the secondary D-Channel will get configured on. (Default is Not Used)
NFAS Supported
Select Yes from drop down if NFAS is being configured. Select No if configuring FAS. If IMG 2020 is configured for the E1 protocol, the NFAS Supported field will be shaded green and it cannot be modified.
Note
NFAS is supported over T1 with the NI-2, 4ESS/5ESS, and DMS 100/250 variants.
It is not supported over E1 with the Euro ISDN variant, or over T1 with the JATE variant.
Base Variant
Select from the drop down menu which Base Variant will be used. Verify that the correct side is being configured. (Either User or Network). The default is National-ISDN 2 Network Side.
Note: Depending on which Base Variant is being configured will dictate the number of B-Channels that can be configured. The table below lists the variants supported and number of B-Channels that can get configured for each. The table below does not include the span that the D-Channel is configured on.
Base variant (network or user) | B-Channels IMG 2020 |
National-ISDN 2 (NI2) | 20 spans (479 channels) |
ATT 4ESS Q.931 PRI | 10 spans (239 channels) |
ATT 5ESS Q.931 PRI | 10 spans (239 channels) |
Northern Telecom DMS-100 Q.931 PRI | 10 spans (239 channels) |
Northern Telecom DMS-250 Q.931 PRI | 10 spans (239 channels) |
JATE | 10 spans (239 channels) |
Net5 Q.931 (10.3.3 ER2) | 10 spans (239 channels) |
B Channel Selection
Select from a drop down menu which method to use to access a B-Channel when a call comes into the IMG 2020. The Default value is Linear Clockwise.
Linear Clockwise (default) - The search for an idle B-Channel begins at the first B-Channel in the D-Channel FAS/NFAS Group and proceeds in order towards the last B-Channel.
Linear Counter Clockwise - The search for an idle B-Channel begins at the last B-Channel in the D-Channel FAS/NFAS Group and proceeds in order towards the first B-Channel.
Circular Clockwise - Starts at the first channel in the channel group and routes down. If a prior channel becomes available this channel is used before selecting the next channel from the end of the list.
Circular Counter Clockwise - Starts at the last channel in the channel group and routes up. If a prior channel becomes available this channel is used before selecting the next channel from the end of the list.
HDLC Bit Polarity
Select from drop down menu whether Bit Polarity is Normal or Inverted.
Bit Polarity Selections |
Normal (default) |
Inverted |
Network Side Layer 2 Override
Select from drop down menu whether the D-Channel being configured is to be configured on the Network or User Side. If the opposite entity connected to the D-Channel on the IMG 2020 is set as the Network side, the D-Channel should be set as the User side. If the opposite entity connected to the D-Channel on the IMG 2020 is set as the User side, the D-Channel should be configured as the Network side.
Location
The value populated in the Location parameter in the Cause IE when a call is released. Location values include:
Property | Value | Description |
User | 0x0 | Default. Message generated by user. |
Local private Network | 0x1 | Message generated by private network serving the local user. |
Local public network | 0x2 | Message generated by public network serving the local user. |
Transit network | 0x3 | Message generated by transit network. |
Remote public network | 0x4 | Message generated by public network serving the remote user. |
Remote private network | 0x5 | Message generated by private network serving the remote user. |
International network | 0x7 | Message generated by international network. |
Network Beyond interworking point | 0x0a | Message generated by network beyond inter-working point. |
Monitoring Fields
Primary D Channel Status
Monitors and displays the status of the Primary D-Channel.
Secondary D Channel Status
Monitors and displays the status of the secondary D-Channel.
Buttons
In Service - Clicking on the In Service button brings the configured D-Channel In Service. If both a Primary and Secondary D-Channel are configured, both the Primary and Secondary D-Channel will be brought back into service. Note that a switchover may have occurred when the Primary and secondary D-Channels were taken Out Of Service.
Out Of Service - Clicking on the Out of Service button takes the D-Channel configured Out Of Service. If both a Primary and Secondary D-Channel are configured, both the Primary and Secondary D-Channel will be taken Out Of Service.
Switch Over - By clicking on the Switch Over button, The Primary D-Channel which was previously in the active state will switch and go into the standby state. The Secondary D-Channel which was previously in the standby state will switch and go into the active state.