
6-4 Netopia ISDN Modem User’s Guide
Using Multilink PPP
The Netopia ISDN Modem supports Multilink PPP, which can link the two ISDN B channels and allow a maximum digital connection of 128 Kbps. Multilink PPP is enabled by default.
If want to use Multilink PPP, make sure:
■Multilink PPP is turned on in the Netopia ISDN Modem.
■The serial port of your PC or Macintosh computer supports a data transmission rate of at least 115.2 Kbps and you’ve set the port speed in your communications software to the maximum available data rate.
■Both the telephone company service and the Internet Service Provider (ISP) or LAN
■Both you and the destination you are calling are using software that supports PPP, such as
The following registers control Multilink PPP and are set by your configuration software:
■S register 80 enables or disables Multilink PPP operation
■S registers 82 and 83 control Multilink configuration
■S register 70 controls Dynamic Bandwidth Allocation (DBA) in Multilink mode
By default, the Netopia ISDN Modem dials the same number for both Multilink PPP channels. If the destination requires a different telephone number to establish a second Multilink PPP channel, then you must include this second telephone number in the dial string. The ampersand character (&) is used to dial two telephone numbers: for example, ATD19085557891 & 19085555555
Note: If you are using a Macintosh computer and a Model 411 Netopia ISDN Modem, start up the ISDN Setup application and enter the second telephone number (DN) in the Second DN field in the Advanced window. (For more information, see the “Second DN” section on page