Dear all,

I have a quick question regarding my DrayTek 2820Vn (very latest firmware) and wonder if someone could help?

My ADSL currently is sync'd at 832000 up and 6432000 down (although this can vary from 6000000 to 7000000 when I log on). However, the speed I actually obtain during any speed or download test is more like 5000000 (~5mbps).

This is fine (but annoying!) and I fully understand that I lose around 1Mbps in comparison to the sync speed in Online Status.

My question is, how does this affect Bandwidth Management and QoS options in the Router? How does the Router know that I sync at 6Mbps but only can achieve 5Mbps realistically?

If it cant, is there a way to get the router to 'understand' this fact so that I can set BM and QoS efficiently?

Thanks in advance.

Brad

The 'missing' bandwidth is taken up by overhead traffic. The sync speed is the maximum possible throughput, and does not take into account the overhead, or any packets that must be re-transmitted due to errors.

Just set your QOS and Bandwidth Management to allocate percentages of your bandwidth, then it will all scale up and down with your connection speed.

Sync speed and actual download speed are not the same. Many ISP's use traffic shaping - especially those that seem to offer remarkable value for money - which will throttle your actual download speeds at peak times.

also note by default QOS is set to use upto 80% of availble bandwidth, this could be losing you some speed if you have QOS switched on.
Telnet to your router and try:

adsl rxpct ?

adsl txpct ?

Setting these higher (ie closer to 100%) will maximise your download speed.
It may of course also stop QOS being as effective, no such thing as a free lunch right!