kppp

Hi all: I am using an ISA 56K modem (not win as far as I know), and have managed to get it working by various configurations including setserial. I am using Uklinux and it connects at 115K but using kppp stats I see that it consistently leaps and troughs quite badly and keeps stalling. The average speed is about 600b/sec. Using a different modem on another machine I get a good through rate with the same uklinux phone numbers so I assume it is some setting in the modem itself or one on the linux box that is awry? It seems to go quite quickly and gradually die and then continuously stall. Any tips for configuration or trouble-shooting? Paul