Line Attenuation vs Line Speed?

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BronxNZ

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#26129 12-Sep-2008 15:31

Hi guys, just a general query regarding why my speed tests results seem to be slow based on my Line Attenuation. See below for the relevant info:

ISP Details:
ISP: Vodafone
Plan: Ultimate (Max/Max)

Router Details:
Linksys WAG200G (with latest firmware)
DSL Status: Connected
DSL Modulation Mode: MultiMode
DSL Path Mode: Interleaved
Downstream Rate: 7616 kbps
Upstream Rate: 704 kbps
Downstream Margin: 19 db
Upstream Margin: 12 db
Downstream Line Attenuation: 4 db
Upstream Line Attenuation: 1 db
Downstream Transmit Power: 11 db
Upstream Transmit Power: 9 db

Speedtest Results (Sun 4:30pm):
Download Speed: 3033 kbps (379.1 KB/sec transfer rate)
Upload Speed: 596 kbps (74.5 KB/sec transfer rate)
Latency: 48 ms

I've tested the speeds at varying times of the night and day and have not managed to get above 3250 kbps Down. Also of note the test above was done on an ethernet connection rather than wireless with no telephone extension cords used.

One last thing that may be affecting my speeds is my house is relatively new (4 years) and was connected with fibre-optic (I think). Also used to have a monitored alarm with AlarmNZ but got their technician to re-wire for broadband.

I'm connected through the Massey Exchange (I believe) but I'm right on the outskirts of this, Scenic Drive between Kitewaho Road and Te Henga Road. Looking at the cabinet info on the thread " think i got cabinetised..." I'm outside of a cabinetised area so should in theory be able to connect up to Vodafone Red Network but then is it going to increase my speeds any?

Any suggestion appreciated, thanks.

eXDee

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#164041 12-Sep-2008 17:12

You're syncing at near full speed ADSL1 so any issues with speed you're having are likely to be on vodafone's end. The line they give you about things like congestion etc affecting your speed is true, speed depends on many things such as how much bandwidth they purchase, which Orcon doesn't seem to be able to get right. Different ISP's can give different speeds to different servers, after switching to Telstraclear from vodafone my latency decreased and my average speed increased for example

If you want a real maximum test of speed the best way to do it is off a fast server, eg Microsoft who uses Akamai, and download a file using a download manager set to open multiple connections and split the file up. I only get around 6000kb/s on a speedtest but 10000kb/s using a download manager.

Spyware

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#164043 12-Sep-2008 17:24

Go to http://www.speedguide.net/ and run the TCPIP Analyzer. Compare with below results.

« SpeedGuide.net TCP Analyzer Results »
Tested on: 09.12.2008 01:18
IP address: 125.236.xxx.xxx

TCP options string: 020405b40103030301010402
MSS: 1460
MTU: 1500
TCP Window: 513920 (multiple of MSS)
RWIN Scaling: 3
Unscaled RWIN : 64240
Recommended RWINs: 64240, 128480, 256960, 513920
BDP limit (200ms): 20557kbps (2570KBytes/s)
BDP limit (500ms): 8223kbps (1028KBytes/s)
MTU Discovery: ON
TTL: 45
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

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BronxNZ

23 posts

Geek

#164101 12-Sep-2008 20:37

Thanks for the replys. My results from SpeedGuide are below with the main differences highlighted:

############ Original Results ############

« SpeedGuide.net TCP Analyzer Results »
Tested on: 09.12.2008 03:57
IP address: 118.93.xx.xx

TCP options string: 020405b401010402
MSS: 1460
MTU: 1500
TCP Window: 17520 (multiple of MSS)
RWIN Scaling: 0
Unscaled RWIN : 17520
Recommended RWINs: 64240, 128480, 256960, 513920
BDP limit (200ms): 701kbps (88KBytes/s)
BDP limit (500ms): 280kbps (35KBytes/s)
MTU Discovery: ON
TTL: 115
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

Looking at it and reading some more info maybe the RWIN value was reducing my down speed so I optimised the settings and ran the test again.

############ Optimised Results ############

TCP options string: 020405b40103030201010402
MSS: 1460
MTU: 1500
TCP Window: 256960 (multiple of MSS)
RWIN Scaling: 2
Unscaled RWIN : 64240
Recommended RWINs: 64240, 128480, 256960, 513920
BDP limit (200ms): 10278kbps (1285KBytes/s)
BDP limit (500ms): 4111kbps (514KBytes/s)
MTU Discovery: ON
TTL: 51
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

Still no change to Download speed however, although I am checking in peak times at the moment, Will check again during off-peak.

Speedtest Results (Fri 8:30pm):
Download Speed: 2875 kbps (359.4 KB/sec transfer rate)
Upload Speed: 567 kbps (70.9 KB/sec transfer rate)
Latency: 50 ms

coffeebaron

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#164172 13-Sep-2008 10:46

Hi Gareth,

You will be connected to a roadside cabinet, most likely the one at the beginning of Waitakere Rd. You will not be able to get on Vodafone's Red network for quite some time; i.e. after sub-loop unbundling.
The mostly likely issue affecting your maximum speed is the feed to that cabinet; many of these earlier cabinets are feed by a 2 or 4 Mbps link; therefore you result maxing out as it does.

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BronxNZ

23 posts

Geek

#164410 14-Sep-2008 23:08

Hi Fraser,

Thanks for the input, its always good to get someone elses knowledge on the subject.

There is a cabinet just prior to Te Henga Road, about 20 meters from my house that is not included in the cabinetised areas indicated on the thread "I think i got cabinetised..." I was wondering if this is what I'm connected to due to the low attenuation rates I'm seeing on my router.

Even with the sub-loop unbundling would this help me out as doesn't this just enable the other telcos to install their equipment into the cabinets and therefore the feed connecting the cabinet is still going to limit my downloads?

Cheers.

cyril7

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#164435 15-Sep-2008 07:37

The older cabinets as you would appear to be connected to, have Conklin DSLAMs in them that only support a single or dual E1 uplink, hence a maximum rate of 4Mb/s for the uplink from the cabinet. If not on the list for the current cabnetisation plan then its possible it will be sometime before it gets upgraded either by Telecom for its use or the still to be determined sub loop unbundling.

Cyril