Is it possible to change a Vigor 2820 router with Annex A firmware to an Annex B router just by changing the firmware on it? I would like to use the Vigor 2820 Annex A router with a Dialog line in Poland (DialNET). I'm currently using an Annex B router to connect to the internet, but I'm unable to find an Annex B version of Vigor 2820.

I'd also like to confirm that Vigor 2820 will work on an ADSL2+ line with 100 Mbit/s download and 20 Mbit/s upload.

It used to be the case that the chipset is different, but I'm not so sure on the latest routers.

Perhaps someone from DrayTek could confirm this? I read on the internet that the hardware filters are slightly different in Annex A and Annex B modems. But then again I read some stories of users successfully converting their routers simply by flashing different firmware (although I haven't been able to find any information about converting DrayTek routers).

That's one amazing ADSL2+ line if it's for real , ADSL2+ as a standard tops out at 24Mbps with perhaps 2-3MBps upload in perfect conditions - you may be referring to VDSL2+? That standard possibly can do that speed if what I've heard about BT infinity connections is true.
The 2820 is ADSL2+ or ethernet only, and the WAN throughput in my experience tops out at about 65MBps up/down.
If you want to use a VDSL2+ connection with the 2820, you'd need to use a separate modem with the router's WAN2 port, which is how BT's infinity service is currently done.

The hardware between the Annex A and Annex B models is definitely different, they even use different port connectors from what I've seen - RJ45 instead of RJ11.

Whether you can do this just by re-flashing, I don't know - I think so*. (G992.1) Annex A is for ADSL over PSTN lines - the pilot frequency is quite different (from memory, 270KHz Vs 400KHz??) to that used in Annex B which is for ADSL over ISDN lines. The frequencies/channels ('bins') that are used in Annex A are, in Annex-B, used for 2B+D ISDN.

Meanwhile, as mentioned by Voodle, Annex B uses an RJ45 connector, which is standard in the ISDN world, where it's called S-bus / S0. ISDN is a FOUR-wire system (post NTE). So unlikely to work on a 2-wire system.

* The DRAYTEK.PL site has annex A & B F/W versions, in both Polish and English for 3.3.4 and English only, I think, for 3.3.5. So, do you feel lucky??

- S

so, i do not understand.
is it possible to switch annex a to b (or vise versa ) in 2820 version just by flashing new firmware or not?
is anybody do it ?
is any confirmation?