You are here: CSP Developer’s Guide: Common Channel Signaling > 8 ISDN > ISDN D Channel Configuration

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

Frame

0xFE

1, 2

Length

0x000E

3, 4

Message Type

0x00C4

5

Reserved

0x00

6

Sequence Number

0x00

7

Logical Node ID

0x01

8

AIB
Address Method

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
T203 = 15 s (D Backup) or 30 s
N200 = 3

N201 = 260
ACK Pending timer = 0.5 s
k = 7
L2 Options = 0

Lucent 4ESS (0x01)

Lucent 5ESS (0x02)

 

PPL Timers

L3 Call Control Component (0x08)

T303 = 4 s
T305 = 4 s
T308 = 4 s
T310 = 25 s
T313 = 4 s

 

PPL Config Bytes

L3 Call Control Component (0x08)

#1 = True
#2 = False
#3 = False
#4 = 0x03

#5 = False
#6 = False
#7 = 1 (Number of setup resends)
#10 = False

PPL Config Bytes

L3 Global Call Reference Component (0x09)

#1 = False
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = False

 

Other

 

Restart Procedure initiated

DMS100/250
(0x03/0x04)

ISDN Terminal Configure

LAPD Entities

T200 = 1 s
T203 = 30 s or 15 s
(D Backup)
N200 = 3 s

N201 = 260
ACK Pending timer = 0.5 s
k = 7
L2 Options = 0

DMS100/250
(0x03/0x04)

PPL Timers

L3 Call Control Component (0x08)

T303 = 4 s
T305 = 4 s
T308 = 4 s
T310 = 10 s

T313 = 4 s

PPL Config Bytes

L3 Call Control Component (0x08)

#1 = True
#2 = False
#3 = False
#4 = 0x03

#5 = False
#6 = False
#7 = 1
#10 = False

PPL Config Bytes

L3 Global Call Reference Component (0x09)

#1 = False
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = False

Other

 

Restart initiated

AUSTEL
(0x05)

AUSTEL

Netside
(0x15)

 

ISDN Terminal Configure

LAPD Entities

T200 = 1 s
T203 = 10 s
N200 = 3 s
N201 = 260

ACK Pending timer = 0.35 s
k = 7
L2 Options = 0x02 (stop sending SABME after N200)

 

AUSTEL
(0x05)

AUSTEL

Netside
(0x15)

PPL Timers

L3 Call Control Component (0x08)

T304 = 15 s
T305 = 30 s
T308 = 4 s
T313 = 4 s

 

PPL Config Bytes

L3 Call Control Component (0x08)

#1 = True
#2 = False
#3 = False
#4 = 0x03

#5 = False
#6 = False
#10 =False

 

PPL Config Bytes

L3 Global Call Reference Component (0x09)

#1 = False
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = False

PPL Config Bytes

L3 D Channel Control Component (0x0A)

#1 = True

 

B Channel Options

 

Network Specific = 0x01 (no NSF)
Calling Number Type = 0x01 (unknown)
Called Number Type = 0x01 (unknown)

PCM Encoding Format

 

a-law

Other

 

Restart procedure is not supported.
The ISDN card automatically responds to a valid SETUP message with both a CALL PROCEEDING and an ALERTING message.

JATE
(0x06)

ISDN Terminal Configure

LAPD Entities

T200 = 1 s
T203 = 30 s
N200 = 3 s
N201 = 260

ACK Pending timer = 0.5 s
k = 7
L2 Options = 0

JATE
(0x06)

PPL Timers

L3 Call Control Component (0x08)

T303 = 4 s
T305 = 4 s
T308 = 4 s
T310 = 30 s
T313 = 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
#2 = False
#3 = False
#4 = 0x03

#5 = False
#6 = False
#7 = 1
#10 =False

PPL Config Bytes

L3 Global Call Reference Component (0x09)

#1 = False
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = False

PPL Config Bytes

L3 D Channel Control Component (0x0A)

#1 = False

 

B Channel Options

 

Network Specific = 0x01 (no NSF)
Calling Number Type = 0x01 (unknown)
Called Number Type = 0x01 (unknown)
Calling Number Plan = 0x01 (unknown)
Called Number Plan = 0x01 (unknown)

PCM Encoding Format

 

a-law

 

Other

 

Restart procedure is supported
For an outgoing call, a 55-second timer is started after the ALERTING message is received. If the timer expires before a CONNECT message is received, the call is cleared (a DISCONNECT message is sent).

EURO
(0x07)

 

ISDN Terminal Configure

LAPD Entities

T200 = 1 s
T203 = 10 s
N200 = 3 s
N201 = 260

ACK Pending timer = 300 ms
k = 7
L2 Options = 0

EURO
(0x07)

PPL Timers

L3 Call Control Component (0x08)

T301 = 180 s
T302 = 15 s
T303 = 4 s
T304 = 15 s
T305 = 30 s

T308 = 4 s
T310 = 25 s
T313 = 4 s
T322 = 4 s

PPL Config Bytes

L3 Call Control Component (0x08)

#1 = True
#2 = False
#3 = False
#4 = 0x03
#5 = False

#6 = False
#7 = 1
#8 = False
#9 = False
#10 = False
#11 = False

#22 =3

PPL Config Bytes

L3 Global Call Reference Component (0x09)

#1 = False
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = False

PPL Config Bytes

L3 D Channel Control Component (0x0A)

#1 = False

 

B Channel Options

 

Network Specific = 0x01 (no NSF)
Calling Number Type = 0x01 (unknown)
Called Number Type = 0x01 (unknown)

PCM Encoding Format

 

a-law

 

Other

 

Restart procedure is not supported

NI2 User (0x09)

 

See NI2 Netside (0x19)

EURO

NETSIDE
(0x17)

ISDN Terminal Configure

LAPD Entities

T200 = 1 s
T203 = 10 s
N200 = 3 s
N201 = 260 s

ACK Pending timer = 300 ms
k = 7
L2 Options = 0

EURO

NETSIDE
(0x17)

PPL Timers

L3 Call Control Component (0x08)

T302 = 15 s
T303 = 4 s
T304 = 20 s

T305 = 30 s
T308 = 4 s
T310 = 25 s

PPL Config Bytes

L3 Call Control Component (0x08)

#1 = True
#2 = False
#3 = False
#4 = 0x03
#5 = False

#6 = False
#7 = 1
#8 = False
#10 = False
#11 = False

PPL Config Bytes

L3 Global Call Reference Component (0x09)

#1 = False
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = 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)
N200 = 3

N201 = 260

ACK Pending timer = 0.5 s
k = 7

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
T305 = 4 s
T308 = 4 s

T310 = 25 s
T313 = 4 s

T322 = 4 s

 

PPL Config Bytes

L3 Call Control Component (0x08)

#1 = True
#2 = False
#3 = False
#4 = 0x03

#5 = False
#6 = False
#10 =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
#2 = 2
#3 = False
#4 = False
#5 = False

#6 = False
#7 = False
#8 = False
#9 = False
#10 = 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
Address Method

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
Address Type

0x0D (Channel)

11

Data Length

0x03

12, 13

Data[0,1] Logical Span ID

0x0000

14

Data[2] Channel

0x17

15

Address Element 2
Address Type

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)