After successfully configuring my Draytek to talk to Jazztel I thought I’d try the Annex M option they offer which improves the uplink bandwidth relative to the downlink speed.
This seems to have worked quite well as can be seen below. Here are the different synchronisation speeds.
Without Annex M:

With Annex M:

That’s quite a difference especially if the upload speeds are important.
I’ve already been told that my video over Skype is better and also noticed less problems with VoIP although the increase from 320 kbs I had with Telefónica is sufficient to avoid many of the dropouts I had experienced earlier.
Here is the Jazztel configuration I’m using:

Hopefully if you are considering using this router this information may be helpful to you.
Hi,
Recently I bought a vigor 2820vn and the info provided in this article has been very useful. I’ve got a little problem with my jazztel connection, even if sync speed is perfect (2.5 Mbps) I can’t get upload speed faster than 1-1.1 Mbps (my old linksys in the same tests achieved 2.2-2.3 Mbps).
I’ve read that some firmware versions are better depending on the country and ISP, could you tell me which one you’re using? I started using the tagged as standard and now I changed to 2121501 (provieded by draytek.es) thinking that it would help, but I haven’t noticed any improvement.
Any suggestion?
Thanks in advance.
Hi Daniel.
I´m not sure that I can suggest anything but bear in mind that the sync speed at the layer 2 level (ADSL) may have nothing to do with the actual bandwidth you can achieve using tcp/ip. That maybe be due to the connectivity of the other end of the connection, or perhaps due to Jazztel´s own bandwidth limitations or filtering. I guess you´d need to do some side by side tests with your old ADSL router to the same destination compared to the Vigor, and also confirm the exact connection configuration of both routers.
Good luck with getting better performance and I´d be interested in hearing if you come to any conclusion on the matter.