UPC Chello light and Linux problems and solutions

I am not sure if it is the Laptop (HP/Compaq nx6125), the distribion (Ubuntu Linux 6.06), or if those damn cable modems are too stupid, but the combination of the mentioned laptop and distribution with the extremely speed-reduced cable TV based internet access product Chello light does not work stable.

It seems that the extreme speed reduction (from 10 mbit brutto not to 3072/512 or 6144/768 kbit typical product speed but to ISDN typically 128/64 kbit) and the (quite effective) IP stack of Linux seem to overstrain the cable modem. The situation gets even worse if an iptables firewall is active.

The joke and solution is: With a DSL router (NetGear in this case) inbetween (not for forbidden multiplexing, only for security and reliability) the connection works like clockwork! 
Weird.


From: IBCL BLog.
Originally posted: 2006-08-06