Kitz Forum
Broadband Related => ADSL Issues => Topic started by: mahmoud34abc on March 04, 2023, 02:42:52 PM
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I need help with my noise margin as it's very high and the speed is really crippled. Is there any way to reduce the noise margin without having to buy a new line?
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Welcome to the kitz forum. :)
We really need more information before anyone can assist you with some advice.
I suspect you are not based in the UK. Is that correct?
Who is your service provider?
Which ZTE device (modem/router) are you using?
Although it is displayed as "Noise Margin" by the ZTE device, it is really the Signal to Noise Ratio margin.
Have you asked your service provider if they would be able to reset the target signal to noise ratio margin (SNRm) to 6 dB.
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Yes, I'm in Egypt
The router is ZXHN H108N V2.5, with WE (the service provider) logos and color schemes on the pages and printed on the router
I suppose the higher the SNR ratio, the better the internet should be, right?
I haven't asked them honestly, but I'll try now. Hopefully they can assist as the customer support is usually not really professional.
Thanks! :) :fingers:
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Welcome in :) I am from Egypt too with WE (the fastest ISP in the universe) :comp:
I am actually suffering from the same speed drop issue recently from 17th Feb 2023, though my line is VDSL and I called them to fix the speed drop issue and they did but speed dropped 2 days ago within less than a month.
I would call them to increase the speed or you can simply do a complaint through MY WE app and they will call you back and fix it but expect the same issue again because when they called me back the agent said "sorry it is an error within our system and it will be fixed" but as I mentioned above the speed dropped again, so I am really considering changing ISP because WE is not delivering high speeds when the line is capable of (in other words they are manipulating sync. line speeds on purpose).
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That's exactly what happened to me too! Except they haven't raised the speeds, but the lines are indeed capable of holding enough bandwidth. They might blame it over the router you're using calling it "too old". For me that isn't the case because I bought this router in like 2019, it isn't that old. But I'll try to swap it with another one once I find where it is. Try saying you have weaker speeds instead of directly asking them for a speed increase? Also make sure the fixed voice bill is also paid
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Try saying you have weaker speeds instead of directly asking them for a speed increase? Also make sure the fixed voice bill is also paid
Yes instead of saying increase speed I would say that the speed I am getting is slower than what I am paying for, also the bill is paid :shrug2:
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Welcome to the forum!
As Burakkucat says, your ISP will be able to set your downstream target SNR margin back down to 6 dB or whatever suits your needs. If you find that they don’t understand what you’re talking about, then you obviously need to ask to speak to someone more technical, and, failing that, to change to a much more clued-up ISP. Reducing the SNRM will make the line faster but less reliable - it’s always a speed-reliability tradeoff. But your line might now be perfectly fine at 6 dB SNRM, which is the usual downstream target SNRM value, if the line had a problem in the past and it has now gone away. Some network operators have an automatic system that adjusts target SNRM depending on how many errors they have seen over a certain period of time, raising the target SNRM if there are a lot of errors and then hopefully (!) reducing it back down when things improve, but that can sometimes take ages.
By ‘reliable’ I mean that there will be fewer corrupt packets (messages) received by either modem. Corrupt messages are thrown away. Sometimes these “dropped packets” are resent by the computer that sent them, sometimes they are not, depending on the type of “transport layer” protocol used over the internet. This at best slows things down a lot or at worst lost packets cause some kind of failure of a conversation between computers. Some top quality modems can break messages up into parts and resend these parts over the DSL link to the other modem if these part-messages get corrupted. Modems based on a Broadcom internal chipset are the ones to go for. This modem-to-modem ("layer 2") retransmission software gives superb reliabilty and high speed. The ADSL2 version of this modem-internal software from Broadcom is called "PhyR". In FTTC modems, the same thing is called G.INP.
‘Reliable’ can also mean that the modems sometimes cannot cope with the level of noise and packet corruption and have to drop the connection and reconnect (called a resynch or retrain), which takes about 70 secs and so is a big nuisance. This will more frequently occur with a lower target SNRM whenever there is temporary high level of external interference (noise) or some line fault and this overwhelms the error correction abilities of the modem, which are greater with higher SNRM.
Both types of unreliability can be prevented, as well as by having a higher SNRM, by increasing the "interleaving depth" setting. This is not something you can control exactly, but your ISP will be able to turn interleaving on (best reliabilty), or off (bad) or use a medium interleaving depth setting. Setting interleaving to "on" will make things more reliable, especially in the case where there is a noise spike/burst. Noise bursts that are of really long duration are a big problem, one for which there are no clear answers as far as I’m aware.
I see that indeed your SNRM gargling both up and down are very high. You have interleaving turned on, on a high interleave depth setting, which is good.
@Fellow kitizens, what on earth is interleave depth 320 supposed to be? Looks like a bug in the modem’s stats display routines? Also the delay values look insanely high. What’s going on?