I did this by crimping some RJ11 plugs on around 10-15m of CAT5.
Upon checking the max attainable rate, I discovered it'd gone up by nearly 2000kbps - rising from the low 88,000s to the high 89,000s, despite going from a 1m cable to 10m! I've been logging the data from my ECI modem since I had it, and the max attainable has never moved from the low 88,000s.
It makes me wonder what gains are to be had from using a short, high quality twisted pair cable in lieu of the supplied item.
Edited by mikehiow (Thu 25-Apr-13 00:58:45)