ISDN D-Channel

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 and a set of attributes such which Span/Interface and Channel the D-Channel will reside. 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.

 

ClientView Pane

IMG EMS > Logical IMG > IMG Name > Signaling > ISDN > ISDN D Channels > ISDN D Channel

SC_ISDN_DChannel_Pane.png

 

Maximum Objects

T1 - Up to 28 D-Channels.
E1 – Up to 32 D-Channels.

 

Related Topics and Dependencies

Configuring ISDN

ISDN D-Channels

 

Field Descriptions

Primary Interface - Offset

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.

 

NFAS Supported (T1 Only)

Select Yes from drop down if NFAS is being configured. Select No if configuring FAS. If 2020 IMG is configured for the E1 protocol, the NFAS Supported field will be shaded green and it cannot be modified.

 

Secondary Interface - Offset (NFAS only)

If configuring a secondary D-Channel select which channel the secondary D-Channel will get configured on. (Default is Not Used)

 

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)

 

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 2020 IMG

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 an IMG. The Default is 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 1st 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.

 

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 2020 IMG 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 2020 IMG 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.

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

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

 

Object Table Tab

This table shows all of the D Channels configured.