ISDN terminal adapter recommendations

There are several different terminal adapters that you can use.

The suggested external ISDN terminal adapter, or ISDN modem, is the 3Com/U.S. Robotics Courier I ISDN V.Everything. It supports V.34 analog modem connections, V.90 (X2), V.92, and Multilink PPP over ISDN in both origination and answer modes on iSeries™ server. It also automatically supports Challenge Handshake Authentication Protocol (CHAP) over the ISDN PPP connection. The following ISDN terminal adapters are also available: Zyxel Omni.net Plus TA, Zyxel Omni.net LCD plus TA, and ADtran ISU 2x64 Dual Port.

Connections that originate from the iSeries server. CHAP challenges that originate from the receiving side are answered by the Courier I terminal adapter, while negotiating Password Authentication Protocol (PAP) authentication with the iSeries server. PAP responses do not appear on the ISDN connection.
Connections that the iSeries server answers. The Courier I requires CHAP authentication by the calling side if the iSeries server answer configuration causes the iSeries server to open authentication with a CHAP challenge. If the iSeries server opens authentication with PAP, the Courier I terminal adapter authenticates with PAP.

If you are using a pre-1999 Courier I modem, verify that the Courier I modem is connected to your iSeries server by a V.35 cable to get the best performance from your ISDN connection. An RS-232 to V.35 modem cable is supplied with the Courier I modem; however, older versions of this cable have the wrong gender V.35 connector. Contact 3Com/US Robotics Customer Support for a replacement.

Note: According to 3Com/US Robotics, the V.35 version of this terminal adapter is no longer , though some may still be from third party suppliers. The RS-232 version is still suggested at somewhat reduced performance on iSeries, since RS-232 connections are limited to 115.2 Kb.

You can also obtain a V.35 to RS-232 adapter from Black Box Corporation. The part number is FA-058.

Be sure to set the V.35 line speed on iSeries server for 230.4 Kbps.