Update on CenturyLink DSL Connection Problems

In CenturyLink DSL connection problems I described a problem where my modem would hangup with no pppd exit status whenever my connection was saturated. I suspected a problem at the DSLAM and called CenturyLink support. They agreed to put me on a blacklist of subscribers for whom line-monitoring software causes issues. This had to get approved by a tier 3 technician. While it prevented the problem from happening every time, I still saw connection drops when downloading large files at a high speed. I needed my own solution and it was a bit of a depressing one. My ADSL service is quoted as 12Mbps downlink and dsl_status reports 15.870 Mb/s down / 892 Kb/s up. However, I’ve found through much trial and error that my line is only capable of sustaining 10Mbps. I employed OpenWRT’s qos-scripts to limit my WAN downstream link to 10000kbps. Since then I haven’t seen a connection drop by a simple ‘modem hangup’ with no exit status. I have seen ‘leave showtime’ in the kernel log a few times, which is a similarly terse way of announcing a disconnection, but haven’t tied it to any cause. I have also had LCP timeouts, which is to be begrudgingly expected. I can now download my server backups and other large files without having to constantly monitor my connection, although my effective connection speed is disappointing.