Introduction and Planning Guide

Planning for ISDN

The ISDN interface provides a scalable solution for customers who require high-capacity dial backup between remote sites or cost-effective consolidation of dozens of leased line connections. ISDN interfaces are also used for implementing the DIALs remote access function.

Planning for ISDN in the IBM 2212

The IBM 2212 Models 4xx have four adapter slots, which can be populated with any combination of the ISDN adapters listed in Table 7-1.

The IBM 2212 Models 1xx have one adapter slot, which can contain one of the ISDN adapters in the table.

For maximum flexibility, line service on each port can be individually provisioned.

Table 7-1. Number of B-Channels per ISDN Adapter

Number of B-Channels Supported	Adapter	Feature Code
23	1-port ISDN PRI T1/J1	3106
30	1-port ISDN PRI E1	3107
46	2-port ISDN PRI T1/J1	3108
60	2-port ISDN PRI E1	3109
4	2-port ISDN BRI-U*	3104
4	2-port ISDN BRI-S/T*	3105

Note:

For the ISDN BRI adapters, X.25 on the D-channel is also supported.

Planning for ISDN with your Service Provider

Contact your telephone company to plan for T1/J1, E1, and line service. The sections that follow list information to provide and gather.

Information to Provide to your Telephone Company

When leasing lines from your public telephone service provider, provide the following information for ISDN connections:

Service on the line

Either Primary Rate Interface (PRI) ISDN or Basic Rate (BRI) ISDN

Telephone numbers per line

The number of telephone numbers to associate with each line.

Hunt groups

A hunt group associates one phone number with several channels on a line. When a user dials in, connection occurs over any channel that is free. Note that a single hunt group can be set up over multiple T1 or E1 lines; furthermore, it is not necessary for all hunt group lines to connect into the same IBM 2212. As an alternative to a hunt group, each of the 23 T1 or 30 E1 bearer channels in a line can be called using separate phone numbers.

Number of lines

You will need one line for each port (to determine how many ports are needed, see Table 7-1).

Service agreement

An E1 or T1 line provides continuous signaling. Some service providers detect when signaling is broken and terminate service to the line. Specify in your service agreement the conditions under which it is appropriate to terminate line support.

Information to Gather from Your Telephone Company

You will need to gather the following information from your telephone company:

For ISDN BRI Connections:

Note:

The ISDN BRI U interface is for use only in North America. The ISDN BRI S/T interface is for worldwide usage. S/T can be used in North America with external NT1.

Switch variant

The kind of switch your telco will be using to connect to the 2212 ISDN BRI line. The IBM 2212 supports:

AT&T 5ESS (United States)

Northern Telecom DMS 100 (United States)

USNI1 (United States National ISDN1)

USNI2 (United States National ISDN2)

NET 3 (European ETSI)

INS 64 (Japan)

VN3 (France Telecom)

AUS TS 013 (Australia)

I.430

Telephone numbers

SPID, TEI (auto or fixed), and directory numbers.

For ISDN PRI Connections:

Switch variant

The kind of switch your telco will be using to connect to the 2212 ISDN PRI line. The IBM 2212 supports:

AT&T 5ESS (United States)

AT&T 4ESS

Northern Telecom (DMS PRI)

Australia (AUSTEL) TS-014

INS-Net 1500 (Japan, NTT)

National ISDN 2

NET 5 (Euro-ISDN, ETSI)

I.431 (for T1 PRI, not E1 PRI)

Telephone numbers

Assigned by the telco to your channels.

Line type

In Europe, South America, and certain other countries, use an E1 line. In Canada, the U.S., and Mexico, use a T1 line. Japan requires a T1 or J1 line.

Line build out (LBO)

Line build out is the voltage level on the connector that terminates your line at the 2212. LBO accounts for the distance between the 2212 and the telco, the quality of the line, and the intermediate amplification as specified in dB.

Line coding

For T1, Bipolar 8 Zero Substitution (B8ZS). For E1, High Density Bipolar 3 (HDB3). Alternate Mark Inversion (AMI) for both.

Time slot inversion

Enabled or disabled Zero Byte Time Slot Inversion (ZBTSI).

Data link

Super frame (D4) and extended super frame (ESF) are supported. For ESF, your service subscription will specify ANSI-T1.403, ANSI-IDLE, or AT&T IDLE.

CRC4

Enabled or disabled E1 CRC4 packet checking mechanism.

Publications

More information about ISDN in the IBM 2212 is available in these publications:

• The 2212 Access Utility Installation and Initial Configuration Guide explains how to install the IBM 2212 and its adapters.

• The Access Integration Services Software User's Guide provides details about configuring the IBM 2212 for use with ISDN PRI T1/E1/J1, ISDN BRI S/T, and ISDN BRI-U adapters.