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View Full Version : good dl speed but bad jitter

zer0
16-06-2011, 19:23
my download speed has been good recently but why is my jitter so bad? iv been advised anything over 5ms will cause me to warp across places in online games esp quakelive

i have a direct ethernet cable connection

Downstream Modulation : QAM256
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 5.3 dBmV
Downstream SNR : 38.9 dB
Upstream Modulation : QPSK
Upstream Symbol Rate : 5120 Ksym/sec
Upstream transmit Power Level : 33.7 dBmV
Upstream Mini-Slot Size : 4
https://www.cableforum.co.uk/images/local/2011/06/43.png

http://www.pingtest.net/result/42118585.png
packet loss is 0% but i have java turned off most of the time so it hasnt tested in this pic
SnoopZ
16-06-2011, 19:27
I'm no expert but i think your upstream power level is too low which is the reason for your low upload speed, so you need an engineer out.
zer0
16-06-2011, 19:28
I'm no expert but i think your upstream power level is too low which is the reason for your low upload speed, so you need an engineer out.
i havnt been upgraded to 1mbit upload yet (due sept) so im still on 60k upload
SnoopZ
16-06-2011, 19:30
i havnt been upgraded to 1mb upload yet (due sept) so im still on 60k upload

OK but your upstream power level is a little low i think and needs to be adjusted.
Peter_
16-06-2011, 19:35
OK but your upstream power level is way out of spec i think and needs to be adjusted.
It is actually acceptable click the link. http://www.cableforum.co.uk/board/35251144-post1.html
SnoopZ
16-06-2011, 19:42
It is actually acceptable click the link. http://www.cableforum.co.uk/board/35251144-post1.html

Yes that is the post i was trying to find before you posted it, so it is just in spec, i thought it was just out of spec.
Peter_
16-06-2011, 19:45
Yes that is the post i was trying to find before you posted it, so it is just in spec, i thought it was just out of spec.
I saved it as a bookmark as it is not a sticky.
SnoopZ
16-06-2011, 19:47
I saved it as a bookmark as it is not a sticky.

Yes it should be a sticky it took me a while to find it.
qasdfdsaq
17-06-2011, 04:09
It's on the low side of acceptable. It's also QPSK, which is bad. I don't think it's so much jitter as reduced upstream capacity which combined with congestion results in packet loss, hence warping around in games.
Efour
17-06-2011, 08:19
Im in East London / Essex and since about the start of June The service has been noticeably terrible for gaming in peak hours. Unusable between 4pm and midnight every weekday. massive +15% packet loss

Loads of people are on QPSK upstream, i guess it has a much higher tolerance to errors caused by massive upload congestion.

I tried to upgrade to 30mbit to see if the docsis 3 network was as contended. It is very marginally better than the 10/20mbit one. But add a few more customers and its as bad.

In my long experience with Cable and wireless/NTL/VM this happens every time they upgrade our speeds but have woefully insufficient hardware to actually cope with the job.
Sephiroth
17-06-2011, 10:12
qas is spot on with his diagnosis.

If you're on QPSK and getting poor upstream service (which you are because that's what gaming depends on first and foremost), then it's likely that others on your street are also on QPSK. It's worth checking. Because if they're all on QPSK, their demand will be high, the serviceability low and the channel will be maxed.

That doesn't rule out a dodgy modem, of course - but the group effect of QPSK correspondes with the effects you're reporting.
zer0
30-06-2011, 03:15
bummer, heres what iv got at 3am...

Download Failed (1)
Mick Fisher
30-06-2011, 13:10
bummer, heres what iv got at 3am...

http://www.pingtest.net/result/42808270.png

For some reason, my wired desktop always returns 'unable to test packet loss' and always gets 'B' for quality, whereas my laptop on wireless is able to get a packet loss report which is usually zero and subsequently scores 'A' for quality (mostly).

Conclusions ??? anyone...........
Skie
30-06-2011, 13:36
The packetloss test needs Java installed.
zer0
30-06-2011, 17:04
woo best its been for ages

http://www.pingtest.net/result/42836779.png

i have java turned off but with it on i still get B just without the star

would be interested in some more 10mbit results for comparison if anyone wants to post some www.pingtest.net (http://www.pingtest.net)
Mick Fisher
30-06-2011, 17:30
The packetloss test needs Java installed.
:LOL:

I meant any conclusions on the pingtest giving different results for the same connection.

I do have java installed BTW.
zer0
15-07-2011, 14:11
improved slightly now im on 1mbit upload but not as much as i would like

http://www.pingtest.net/result/43627326.png

new power levels
Downstream Modulation : QAM256
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 1.6 dBmV
Downstream SNR : 37.1 dB

Upstream Modulation : QPSK
Upstream Symbol Rate : 5120 Ksym/sec
Upstream transmit Power Level : 36.2 dBmV