You have to be very careful indeed with these tests, use
proper test methodology of resynching with the
existing modem to make sure that any sync rate change is not simply one that you would have got anyway without even changing modem. Could be that SNR has changed over time, or it could be that DLM is punishing you simply for resynching. I would respectfully say that all our tests do not mean anything without rigorous sanity check procedures being followed, as I have myself got it wrong numerous times (two days ago for instance) and obtained bogus results.
I have recently lost ten percent of some sync rates without changing any kit.
Having said that, the B10A was for me faster downstream in some situations compared with my former DLink DSL-320B-Z1 modems, but not faster in other cases, and sometimes, but not always, the upstream was quite a lot slower. However it was far more stable, never ever loses the connection and resynchs on its own. Also it is not a fair comparison as the DLink modems run at a very very low SNRM often down to 1.5dB or even 0.6dB downstream where the target is 3 dB, whereas the B10A runs at say 3.1dB downstream sometimes drops to 2.5dB. If I tweak the B10A to run at the same low SNRM then it would be about 5% faster than the DLink downstream.
I tested a Draytek Vigor 130 on my extremely slow long ADSL line and it was a mite slow compared to my DLink modems but very solid. So again SNRM needs to be taken into account, which I did not do. The DLink just happens to be very aggressive, so in a way it is cheating, and my comparisons have not been really fair.
For me the B10A is also outstanding because it supports Broadcom’s proprietary PhyR L2 retx protocol, which is the equivalent of G.INP. And this works with my particular DSLAM/MSAN even though this is only ADSL2 not FTTC/VDSL2. This makes it massively more stable.
It may be that the Vigor is especially well suited to your particular DSLAM. I do like the Vigors a lot, very straightforward - you just plug them in and they work. And their PPPoEoE to PPPoA protocol conversion for ADSL users is superb a performance boost due to greater protocol efficiency (less bloat, less wasteful unnecessary data sent). More speed for free for two-box, ie modem plus router, users on ADSL. A built in speed advantage over
all other modems. Doesn’t apply to you of course, but I think it says a lot about the design team that they care, cleverly saw an opportunity and just went for it rather than being lazy. Unless there is some problem created by intellectual property rights, it is amazing that no one else has bothered to implement this excellent performance-enhancing technique. I would get a benefit out of it in some circumstances.
There has been some amount of discussion on the issue of whether there are certain benefits to having modems whose chipset is from the same manufacturer as that of the chipset in your DSLAM. I think Kitz said ‘no’ a long time ago. I don’t know where opinions are nowadays. In my own case there is a special synergy because I happen to now have an exchange with Broadcom chips in the DSLAM/MSANs and these support the important PhyR protocol like my Broadcom-based ZyXEL modem. So it is down to a protocol availability issue, availability of features. Not obviously a case of something deeper involving modems at the two ends thinking alike generally.
Sincere apologies for this insane post which grown into a monster. Bottom line; perhaps retest very carefully and give the modems another chance by passing judgement after vigorous testing and a reasonable length of time to assess performance. Also note SNRM values as otherwise speeds are not being fairly compared.
Edited to correct link at top of post - Roseway
