I have fritz card usb v.2.0. I can connect to isdn interner service provider (ISP) via this card on windows2000 with two channel (128 Kb/s)

And I expert it on Suse 7.1 linux .I have set up it correctly .But I can connect to isdn ISP only one channel (64 Kb/s) .I want to connect with two channel (128 Kb/s). I wonder should I have any other command script. Please help me.