TMnet Streamyx

razhar

razhar

razhar

DS Line Attenuation

25

bermakna jarak dari CO ialah 1.8102824040550325850832729905865km...dekat je...

razhar

What is Attenuation?

Line attenuation is in relation to the "loop loss" on your line. The lower this figure the better, and the better chance you have of getting the faster speeds. Attenuation is a term used to describe the reduction of the adsl signal strength that occurs on the copper pair over distance and is measured in dB decibels. The further you are away from the exchange the higher your attenuation figure will be as the signal loss increases.

Attenuation is logarithmic and each 3dB of attenuation halves the strength of the signal power received, therefore a line with 30dB of attenuation only receives 1/1,000th of the power, whilst a 60dB line would only receive 1/1,000,000th. True line attenuation is measured at the DSLAM at the exchange and this figure should remain fairly static. Our routers can give us an indication of how much the signal is attenuated as an average against all the frequencies that it uses. Because the router measures against the frequencies available, some users may notice a very slight increase in attenuation if say moving from a fixed rate 512 kb connection up to 2Mb. Higher frequencies such as those used to transmit faster speeds are more likely to be attenuated (higher frequencies = higher attenuation). ADSL 2+ has an increased frequency spectrum, therefore an increased attenuation of around 3-4dB is not unusual. As a very rough guide a speed increase of 4Mb is said to increase the attenuation by 1dB. It is also important to note that different routers may load the frequency bins in slightly different ways, and on top of that some routers report the average across the frequencies actually in use, whilst some may report the average across the frequencies available - which is why sometimes using a different router may report a slightly different attenuation figures.

razhar

What is Target SNR?

If you are on a rate adaptive "up to 8Mb" connection (such as MaxDSL or LLU) then Target SNR plays an important role during the synchronisation process between your router and the DSLAM at the exchange. Target SNR affects the speed at which we sync at and sets the initial SNR Margin "buffer zone". You should be able to get a rough idea of your Target SNR by looking at your linestats immediately after a resync.

During the sync process the DSLAM and router negotiate a sync speed based on the various conditions of your line, allowing "spare SNR" for normal fluctuations. With the rate adaptive products, profiles that can be typically set are 6dB, 9dB, 12dB or 15dB -with 6dB being the default. Longer lines are more susceptible to noise and therefore often require a larger margin than shorter lines. Its important to note that on very good lines which would be able to sync in excess of 8Mb and which are currently syncing at 8128 or 7616 will show the SNR Margin as being higher due to the line not having reached its full potential. Such lines may well have the output power reduced in order to minimise crosstalk for other connections, therefore the SNRM figure is not an indication of the target SNR in these particular cases. Fixed rate lines don't have a target SNR as such. The line is set to connect at the fixed speed without any negotiation of line rate, therefore they will either connect at the fixed speed or wont connect at all if the SNR is too low.

razhar

sila  kici2 semua g sini arrr..http://212.23.23.177/calc.asp

ni yg wa punya ..=An estimate of what your line is capable of is 5640kbps (kilo bits per second).

razhar

Low SNR Margin & SNR Problems
Why does this happen?
The most common problem on longer lines is that your SNR is too low to maintain a steady connection.

Traditional Fixed 512/1Mb/2Mb
For each upgrade between the speeds you can expect to lose on average 6dB. Therefore if you upgraded from 512kbps to 2Mbps then your SNR Margin is likely to have dropped in the region of 12dB.
Once your SNR Margin starts to drop below 10dB on a traditional fixed rate line then you can experience problems.

DSL Max + LLU
DSL Max works slightly differently and is more tolerant at working at lower SNR Margins. In many cases it may depend on your modem/router, but generally below 6dB is when problems may start to occur. There are some routers that seem to cope better with low SNR Margins than others. For example there are many cases of the Netgear DG834(G) hanging on right down to 0db and below.

Can I do anything about low SNR?
Depending upon the severity there are different things you can try:-

• Routers are known to provide a more stable connection than usb modems and the purchase of an adsl router has done the trick for many.
  Be aware that some routers do perform better than others on Low SNR Lines, and although there is no guarantee, it is something very well worth trying.
  The Speedtouch 585 + 576, Netgear DG834, Westell 6100, D-Link DSL-G604T are some routers that have specifically been known to maintain a more stable connection on a low SNR line.
  

Noise Spikes
A lot of low SNR problems may be related to noise spikes where "noise" comes from an outside source or electrical interference. You may be able to monitor your SNR Margin and identify a pattern which correlates to your low SNR. Common causes may be microwaves, central heating pumps, street lighting, xmas lights, treadmills, the list is practically endless.

Some users have reported success in tracking down the source of the noise using a portable AM radio. The radio should be tuned in between stations somewhere in the region of 612 Khz until you hear static noise.

[ Last edited by  razhar at 20-1-2009 08:39 PM ]

razhar

Modem Status

Modem Status Connection Status Connected Us Rate (Kbps) 384 Ds Rate (Kbps) 1024 US Margin 23 DS Margin 24 Trained Modulation ADSL_G.dmt LOS Errors 0 DS Line Attenuation 25 US Line Attenuation 13 Peak Cell Rate 905 cells per sec CRC Rx Fast 8 CRC Tx Fast 2 CRC Rx Interleaved 0 CRC Tx Interleaved 0 Path Mode Fast Path DSL Statistics Near End F4 Loop Back Count 0 Near End F5 Loop Back Count 0

razhar

Line Rate, Connection Speed, Bandwidth, Synchronisation Speed.

The speed at which your router has synchronised to the DSLAM at the exchange at. This is commonly called your sync speed.

It should not be confused with your actual throughput (real time) speed since it has an allowance to cover IP, ATM and other various overheads.

The maximum throughput speed on a line syncing at 8128 under ideal conditions would be just slightly over 7Mbps. Other factors such as exchange contention, ISP restrictions or your IP profile will affect your actual throughput speed.

~ SNR Margin, Noise Margin, SN Margin, Local SNR Margin.

The downstream (or local) SNR Margin is normally the most important figure, as this can have an effect on your achievable downstream speed.

SNRM can continually fluctuate depending on various conditions. The higher the SNR figure the better. Because SNR plays such an important role on your adsl connection there's a more in depth explanation on my interpreting your line stats page.

~ Line attenuation, Loop Loss, atten.

Attenuation is the degradation of signal over distance and an indication of the length of your line.
The lower this figure the better.

Generally speaking there isn't much you can do about attenuation, because of its direct correlation to your distance from the exchange.

Because attenuation is an important aspect of your line and the part it plays in adsl there is a more in depth explanation on the interpreting your line stats page.

~ Output power

The amount of power transmitted from the exchange and your modem. Output power will likely increase depending on the length of your line (loop loss).

In this context dBm represents the power ratio of decibels relative to milliwatts, and each 3dB increase is an approx doubling of the power output. The tool on the right converts dBm into milliwatts.

razhar

~ Attainable Rate, Max Rate
The sync rate you could attain if any line card or DSLAM restrictions were removed.
If you see a figure like Max(Kbps): 10048 1048 then this is likely the restriction of the DSLAM on ADSL1. With adsl2+ its possible to get higher speeds.
~ Line Uptime
Most routers will show various up times, each of which are different.
Line uptime is usually the time your router has remained connected to the DSLAM.
Broadband or Internet Connection is usually the time you have remained connected to your ISP (PPP session). Some routers will also show how long the router has been powered up for.


~ Channel Mode or Latency Type
Either FAST or INTERLEAVED. Fast is normal mode, Interleaving can be applied to the line to help increase stability.

[ Last edited by  razhar at 20-1-2009 10:05 PM ]

kazaraf

okeh. aku nk tanye aku nye lak ni.. kalo cmni bagus x???

Modem Status
	Connection Status Connected Us Rate (Kbps) 512 Ds Rate (Kbps) 1024 US Margin 19 DS Margin 31 Trained Modulation GLITE LOS Errors 0 DS Line Attenuation 8 US Line Attenuation 4 Peak Cell Rate 1207 cells per sec CRC Rx Fast 0 CRC Tx Fast 0 CRC Rx Interleaved 0 CRC Tx Interleaved 1 Path Mode Interleaved

razhar

'~ Line attenuation, Loop Loss, atten.

Attenuation is the degradation of signal over distance and an indication of the length of your line.
The lower this figure the better. '

so bagus le.....kao pakai kabel baru kot....

spacey_men

pharez, aku nk tanya sket..

aku nk pindah umah... so nak angkut streamyx aku skali, tapi kat rumah baru aku ingat nak daftar no fon baru, dan maintain je akaun streamyx aku. Line fon yg ada la ni aku tinggal kat rumah mak aku.

Before aku p tm tanya benda2 ni, aku tanya kat forum dulu, jawapan lebih cepat dan tepat..

Ada masalah ke kalau aku nak buat mcm tu? Sbbnya kan akaun streamyx tu diregister atas satu nombor.. kalau nombor tu bertukar, boleh ekk?

kazaraf

boleh... aku da 2x wat cmni sbb pndah rmh. step2 die

- kt TM tu g btau nk tuka alamat tepon n strmmyx - tu jek - xde bayaran kt kaunter - kira no baru kita xtau n x leh pilih
- 3-4 hr pastu. tcnician TM dtg rumh baru...  psg tepon.. baru die bg no baru kita - baya 30 kt die
- 1-3 hari pastu, baru line DSL strmyx UP... (better call TM lpas psg tepon bia cpat sket keje dorg)
- bil bulan akan dtg, ko akan kene caj rm50 pmsgn tepon. itu sahaja.

bzzts

ko nak tanya ke ko nak bgtau ni... nampak soalan ko dah berjawab dgn sendirinya...

razhar

nak tido je....

JAY-Z

tau pun SNR tu aper..tapi kebanyakan banyak yg tak meet benchmark..aper pun..pandai2 la...jangan selalu nak reset port ,nanti rosak port tu   tu yang jay tau laa..apa2 pun jay nyer speed dah 1700kbps

hhbks

fuhh....banyaknya info...

kazaraf

Originally posted by JAY-Z at 21-1-2009 02:36 AM
tau pun SNR tu aper..tapi kebanyakan banyak yg tak meet benchmark..aper pun..pandai2 la...jangan selalu nak reset port ,nanti rosak port tu   tu yang jay tau laa..apa2 pun jay nyer speed dah ...

bole ko share scara ksimpulan ape y ko buat utk capai 1700kbps tuh..
aku nye line bulan 12 leh capai 1500kbps (aku x wat pape pon). tp bulan Jan ni paling tinggi pn 850kbps jek..
SNR aku tgk mcm da bagus..

gepren

Originally posted by pharez at 19-1-2009 04:38 PM
fadzzy, kena check SNR ration ngan line attenuation tgk...kadang upgrade, line jadi tak stabil...

gepren apa masalah tu?

Ada cite kat page 40!