You are here: CSP Developer’s Guide: Common Channel Signaling > 8 ISDN > ISDN D Channel Configuration
Overview
This section describes the second step in the basic ISDN configuration sequence.
• Assigning D channels
• Configuring D Channel options
• Adding facilities (for NFAS)
Assigning D Channels
The D Channel Assign message allocates a D channel at the timeslot you specify. In order for this assignment to succeed, the network interface card on which the D channel is to reside must be in service. The physical span MUST be assigned. You must specify the slot number of the ISDN card, as well as the ISDN type (primary and secondary).
Important! The D Channel Assign message sets all B channel configuration parameters back to their defaults.
The CSP software selects the actual D channel resource. If the host attempts to assign a D channel to a card that already has 32 D channels assigned, the host receives a Response Status of "ISDN D Channel Exceeds Max" (0xA4). You must indicate another card for
D channel processing.
All subsequent references to the D channel timeslot use the Logical Span ID and channel specified in the message. The facility number of 0 (zero) is defaulted to the span with the D channel assignment. When assigning the secondary type, the host selects the facility number.
Requirements for Assigning a D Channel
The following are requirements for assigning D channels:
• Span must be assigned.
• Network interface card(s) must be present and operational.
• ISDN card must be operational and have available D channel(s).
• Span and channel must not be assigned to an ISDN D or B channel location. For most applications, the D channel resides on the 24th channel of the T1 span, and timeslot 16 over E1.
Example
The following is an example of the D Channel Assign message. The example assumes that the Logical Span ID 0 is assigned and that the ISDN card is in slot 4.
Trace H->X FE 00 0E 00 C4 00 00 01 00 01 15 04 04 00 00 17 00
Byte |
Field Description |
Value and indication |
---|---|---|
0 |
0xFE |
|
1, 2 |
Length |
0x000E |
3, 4 |
Message Type |
0x00C4 |
5 |
Reserved |
0x00 |
6 |
Sequence Number |
0x00 |
7 |
Logical Node ID |
0x01 |
8 |
AIB |
0x00 (Single Entity) |
9 |
Number of Address Elements |
0x01 |
10 |
Address Type |
0x15 (Primary D Channel) |
11 |
Data Length |
0x04 |
12 |
Data[0] Slot # |
0x04 |
13, 14 |
Data[1] Logical Span ID |
0x0000 |
15 |
Data[3] Channel |
0x17 (Channel 23) |
16 |
Secondary D Channel Facility Number |
0x00 |
17 |
Checksum |
0xCS (not shown in trace) |
Configuring D channels
The ISDN Interface Configure message configures attributes required for ISDN connections to the public network. To configure the connection endpoint variant, determine the type of switch from which the D channel will originate. This requires consultation with the provider. The default switch type is the Lucent 4ESS.
Normally, you do not need to configure Layer 2 and Layer 3 timers and counters. However, if it is necessary to change these, refer to ITU-T Q.921 and Q.931 for details on what they do and represent.
The table below lists the ISDN interface entities and their defaults. Use the ISDN Interface Configure message to change the default configuration.
Option |
Default |
---|---|
Connection Type |
Lucent 4ESS |
D Channel Physical Medium |
64 kbps |
HDLC Bit Polarity |
Normal |
Network Side Layer 2 |
User Side |
B Channel Selection Mode |
Linear Clockwise |
Location |
User |
Layer 4 Channel Release Request on ISDN DISCONNECT |
Disabled |
Protocol Discriminator Value for Maintenance Messages |
3 |
B Channel Encoding for Transmission |
Channel Number |
Requirements for Configuring D Channel Options
The following are requirements for configuring D channel options:
• The D channel must be assigned.
• The D channel parameters will only be initiated when the transition from out-of-service to in-service occurs.
Reconfiguring D Channels
Follow the steps below to reconfigure a D channel:
1. Take the B Channels out of service with the Service State Configure (0x000A) message.
2. Take the D Channels out of service with the Service State Configure (0x000A) message.
3. De-assign the D Channel with the D Channel De-assign (0x00C5) message.
4. Reconfigure the D channel with the D Channel Assign (0x00C4) message.
5. Reconfigure general options to an ISDN interface with the ISDN Interface Configuration (0x0060) message.
6. Reconfigure B channel information with the B Channel Configure (0x00C8) message
7. Bring span(s), B Channels and D channel(s) back into service with the Service State Configure (0x000A) message.
L3 Default Settings per Connection Type
The table below lists the default L3 configuration values for all connection types currently supported.
Connection Type |
Default Settings |
|||
---|---|---|---|---|
Lucent 4ESS (0x01) Lucent 5ESS (0x02)
|
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s |
N201 = 260 |
Lucent 4ESS (0x01) Lucent 5ESS (0x02)
|
PPL Timers |
L3 Call Control Component (0x08) |
T303 = 4 s |
|
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#5 = False |
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
|
Other |
|
Restart Procedure initiated |
|
DMS100/250 |
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s |
N201 = 260 |
DMS100/250 |
PPL Timers |
L3 Call Control Component (0x08) |
T303 = 4 s |
T313 = 4 s |
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#5 = False |
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
Other |
|
Restart initiated |
||
AUSTEL AUSTEL Netside
|
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s |
ACK Pending timer = 0.35 s
|
AUSTEL AUSTEL Netside |
PPL Timers |
L3 Call Control Component (0x08) |
T304 = 15 s |
|
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#5 = False
|
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
PPL Config Bytes |
L3 D Channel Control Component (0x0A) |
#1 = True |
|
|
B Channel Options |
|
Network Specific = 0x01 (no NSF) |
||
PCM Encoding Format |
|
a-law |
||
Other |
|
Restart procedure is not supported. |
||
JATE |
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s |
ACK Pending timer = 0.5 s |
JATE |
PPL Timers |
L3 Call Control Component (0x08) |
T303 = 4 s |
|
PPL Timers |
L3 Global Call Reference Component (0x09) |
Timer 16: T316 = 120 s |
|
|
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#5 = False |
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
PPL Config Bytes |
L3 D Channel Control Component (0x0A) |
#1 = False |
|
|
B Channel Options |
|
Network Specific = 0x01 (no NSF) |
||
PCM Encoding Format |
|
a-law |
|
|
Other |
|
Restart procedure is supported |
||
EURO
|
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s |
ACK Pending timer = 300 ms |
EURO |
PPL Timers |
L3 Call Control Component (0x08) |
T301 = 180 s |
T308 = 4 s |
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#6 = False #22 =3 |
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
PPL Config Bytes |
L3 D Channel Control Component (0x0A) |
#1 = False |
|
|
B Channel Options |
|
Network Specific = 0x01 (no NSF) |
||
PCM Encoding Format |
|
a-law |
|
|
Other |
|
Restart procedure is not supported |
||
NI2 User (0x09)
|
See NI2 Netside (0x19) |
|||
EURO NETSIDE |
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s |
ACK Pending timer = 300 ms |
EURO NETSIDE |
PPL Timers |
L3 Call Control Component (0x08) |
T302 = 15 s |
T305 = 30 s |
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#6 = False |
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
PPL Config Bytes |
L3 D Channel Control Component (0x0A) |
#1 = False #2 = True Enable T309 logic |
|
|
PPL Timers
|
L3 D Channel Control Component (0x0A) |
T309 = 90 s |
|
|
PCM Encoding Format |
|
a-law |
|
|
Other |
|
Restart procedure is not supported. |
||
NI2 User (0x09) NI2 Netside (0x19)
|
ISDN Terminal Configure |
LAPD Entities |
T200 = 1 s T203 = 15 sec or 30 sec (D backup) N201 = 260 |
ACK Pending timer = 0.5 s L2 Options = 0x08 (Enable Frame Reject Response (FRMR) sending.)
|
NI2 User (0x09) NI2 Netside (0x19)
|
PPL Timers |
L3 Call Control Component (0x08) |
T301 = 5 m T303 = 4 s T304 = 15 s |
T310 = 25 s T322 = 4 s
|
PPL Config Bytes |
L3 Call Control Component (0x08) |
#1 = True |
#5 = False #7 = 0x01 #8= 0x2C #22=0x03 |
|
PPL Timer |
L3 Global Call Reference Component (0x09) |
T316 = 2 m |
|
|
PPL Config Bytes |
L3 Global Call Reference Component (0x09) |
#1 = False |
#6 = False |
|
PPL Config Bytes |
L3 D Channel Control Component (0x0A) |
#1 = False #2 = True |
|
|
PPL Timers |
L3 D Channel Control Component (0x0A) |
T321 = 40 s (user) T321 = 50 s (netside) T309 = 90 s |
|
Example Message
The following is an example of the ISDN Interface Configure message.
Trace H->X FE 00 0F 00 60 00 00 01 00 01 0D 03 00 00 17 01 00 01
Byte |
Field Description |
Value and Indication |
---|---|---|
0 |
Frame |
0xFE |
1, 2 |
Length |
0x000F |
3, 4 |
Message Type |
0x0060 |
5 |
Reserved |
0x00 |
6 |
Sequence Number |
0x00 |
7 |
Logical Node ID |
0x01 |
8 |
AIB |
0x00 (Single Entity) |
9 |
Number of Address Elements |
0x01 |
10 |
Address Element Type |
0x0D (Channel) |
11 |
Data Length |
0x03 |
12, 13 |
Data[0,1] Logical Span ID |
0x0000 (Span 0) |
14 |
Data[2] Channel |
0x17 (Channel 23) |
15 |
Entity |
0x01 (Connection Type) |
16, 17 |
Data[0,1] Value |
0x0001 (Lucent 4ESS) |
18 |
Checksum |
0xCS (not shown in trace) |
Adding Facilities
The D Channel Facility List Configure message adds or deletes facilities controlled by a D channel. For FAS arrangements, facility 0 is assumed for the span with the D channel. By sending the D Channel Facility List Configure message, NFAS is automatically assumed.
Important! NFAS is only supported over T1, not E1.
Specify the span and channel for D and assign the facility number
(1-19 for NI2 and 1-9 for other channel types) and the span ID for the facility being assigned. Each Primary D channel assumes it is located on facility 0. You can add up to 19 facilities with the D Channel Facility List Configure message.
The facility number is the span offset for the controlling D channel. For example, for NFAS the span on which the D channel is located is facility number 0. The next span controlled by that D channel is facility # 1, the next is facility # 2, and so on.
Requirements for Adding Facilities
The following are requirements for adding facilities to a D channel:
• D channel must be assigned (use the D Channel Assign message).
• Facility Number must be from 1-19 (0 is the D channel facility number).
• Facility must be assigned (use the Assign Logical Span ID message).
• Span and channel must not currently be assigned to an ISDN D or B channel location. For most applications, the D channel resides on the 24th channel of the T1 span.
Example
The following example shows the D Channel Facility List Configure message adding Logical Span ID #2, and assigning it to facility #1 for D channel 00,17.
Trace H->X FE [00 12] [00 C6] 00 04 01 00 02 0D 03 00 00 17 0C 02 00 02 01 01]
Byte |
Field Description |
Value and Indication |
---|---|---|
0 |
Frame |
0xFE |
1, 2 |
Length |
0x0012 |
3, 4 |
Message Type |
0x00C6 |
5 |
Reserved |
0x00 |
6 |
Sequence Number |
0x04 |
7 |
Logical Node ID |
0x01 |
8 |
AIB Address Method |
0x00 (Single Entity) |
9 |
Number of Address Elements |
0x02 |
10 |
Address Element 1 |
0x0D (Channel) |
11 |
Data Length |
0x03 |
12, 13 |
Data[0,1] Logical Span ID |
0x0000 |
14 |
Data[2] Channel |
0x17 |
15 |
Address Element 2 |
0x0C (Span) |
16 |
Data Length |
0x02 |
17, 18 |
Data[0,1] Logical Span ID |
0x0002 |
19 |
Action |
0x01 |
20 |
Facility Number |
0x01 |
21 |
Checksum |
0xCS (not shown in trace) |