Update on what has happened so far:
Yesterday I contacted my ISP, they have raised the IP profile problem with the Openreach complex faults team, I should get a response from them within 48 hours. They also ran some more tests on the line, I have attached the reports for these. They found no issues except that the download speeds are below the promised minimum of 60mbps. Today using the ASUS web interface I closed the PPPoE session and started a new one 2 minutes later. After that I ran a BT wholesale speed test again and the IP profile is now 62880Kbps, up from 59564Kbps. The modem is currently syncing at 68256kbps with 3db SNR and ReTx Low and has been since about 5am on 26th December, which means the ReTx problem is solved but the IP profile problem is not.
Some more info about the IP profile:
The last three IP profiles have been 54140kbps, 59564kbps and 62880Kbps. 54140kbps was what I got right after I had a DLM reset on the 7th December, it stayed like that up to the 16th, even after 3 DLM resyncs during that time. 59564kbps is what I got on the 16th after I carefully restarted my modem and router. It stayed like that after a modem/router restart on the 18th and one on the 19th, after restarting the PPPoE session, after leaving the router off overnight, and even after the DLM resync on the 26th December. Today the IP profile changed to 62880Kbps after restarting the PPPoE session.
So from this limited info I have it appears I am experiencing a combination of two bugs:
1. When a DLM resync occurs the PPPoE session is not restarting and applying a new IP profile. This can be seen from the fact the IP profile has never changed without restarting the PPPoE session manually.
2. The DLM system/BRAS is using outdated sync and line profile information. More specifically, it appears to be using information from whatever the line configutation was right before the latest DLM intervention. This is harder to see, whenever the IP profile has updated it has never been correct for the current sync speed and ReTx setting, it has been for a previous one:
.The change to 59564Kbps corresponds to a sync speed of 64743Kbps on ReTx High, at the time my line was: 68164Kbps, 3db, ReTx High (after DLM intervention) and before that was 64731Kbps, 4db, ReTx High. Also see that the fresh test results from my ISP show this old line profile.
.The change to 62880Kbps corresponds to a sync speed of 68347Kbps on ReTx High, at the time my line was: 68256Kbps, 3db, ReTx Low (after DLM intervention) and before that was 68187Kbps, 3db, ReTx High. I suspect that if another GEA test was performed it will now show this old line profile.
Of course this is just speculation from patterns that seem to be emerging, but certainly the automated systems aren't working properly and I hope Openreach complex faults team can see a problem and fix it.
