Very slow connection: Is it ADSL or my wireless network?



I have an Optus supplied SAGEMCOM 3864 modem (1 year old) ADSL+ and the stated speed on the modem live data screen is 14.633Mps down 0.812Mps up (remarkably constant - never changes!).


I have noticed that at certain times of the day, both down/up activities are very slow (even though at the time the modem data screens show the same speed as above): sometimes nothing happens.  So I installed Speedsmart and did a check on down/up speeds (from 7am onwards).  Most times there is no streaming, just use of ipad or  computer for webpages/emails.


Often the speeds are close to the Optus ratings (always lower though), but too often, nowhere near ie download 0.5Mps- 6Mps. Latency can be 20ms (good) to 800ms (not so good).  Upload sometimes hangs completely.


So far I am unable to tell if these slow speed sesions are at a particular time of day: 9 to 11am though seems to suffer a lot.


The question: is it the internet link to Optus or the wireless network at home that is causing the problem?  Or anything else?


It is intermittent and yet beginning to seem to me to be a regular occurrence (ie mornings and evenings)  which suggests an external influence (ie outside the house).  (Next test is to hard wire computer to the modem to see if that makes a difference).


Is there anything else I can do to a) correct or b) narrow down the cause?  (Would regular rebooting help?)


This might be irrelevant.  NBN has been recabling in the road outside on and off for the past 2 months.


Thanks for any thoughts



Re: Very slow connection: Is it ADSL or my wireless network?


Hi @Pozzie,


NBN working in the area can definitely cause issue to existing connections (although usually just constant drops, not periodic)


FWIW 14Mbps / 1 Mbps is about as good as you would expect on ADSL2+


When is the NBN coming to your home (and what technology)? Try the NBN Address Checker


IMO its unlikely to be wifi that is the issue although its possible a neighbour is using the same wifi band as you and this is interfering at some stages. Is there a setting in the modem wifi to change the band used?


First thing to check though is run a wired speed test. Get something directly connected and see if it gives the same speeds as the wifi does (Optus is responsible for speeds to door)


Peter Gillespie

Re: Very slow connection: Is it ADSL or my wireless network?


Hi and thanks PeterG,


I have carried out a cabled test to the modem and the speed results are the same as I found through home wifi (I miscalled that wireless).  I have take quite a few more speed tests and there is a pattern of slow in morning and evening. And sometimes the speed is zero.  


The Sagemcom modem is fixed at 2.4 Band, a pity as the choice of a 5 band may have helped.  I have a bridge in place: Sagemcom as the incoming modem and an TP-Link Archer (2 band unit) as a bridge to the more remote areas. I might try and swop over.  I am aware that Optus has provided very few operating instructions for the 3864 modem.  Is there any way I can tweak it to make things better?   


NBN has just been made available to this area in the FTTC (to the kerb).  I have looked through quite a few posts and see a  speed problem is often reported.  There is so much hype about who's to blame, a lot of which frankly doesn't help much.  As far as I can tell the most common culprit for slowness is "congestion"  ie too many people using the service at once.  But there are specific ISP issues mentioned as well.



The copper network is still owned and managed by Telstra in part or in whole (total handover by July 2020 to NBN?). Optus (as others) just leases its use.  So if there are congestion problems, the issue is the capacity of the copper network for the too many connections through too many service providers.  To me that's an overall system design problem.


If there are cable termination or electronic switching problems (corroded, loose, faulty), I am assuming their repair also falls to the infrastructure owner (ie Telstra/NBN - though practically it'll be a local telecon subcontractor).


But slowness may be caused by the exclusive equipment of the ISP (ie specifically Optus) which feeds into/from the copper (tower, transmitters, whatever, modem).


I know Optus is responsible for the overall service, but because the system has a wholesale/retail split, it is easy to get out of responsibility if the exact problems are masked in obscurity.


Question: is there any way to check where the specfic speed bottleneck is (ideally to locate one or more of: inside Optus; which line from Optus to an exchange; in the exchange, which line to the house)?


NBN is coming.  I have read that slow issues in ADSL will also occur with NBN, because there is still a copper network that either system must use (from node to house presumably).


Is this correct?  And is it possible to identify  where that network is (if mine is FTTC, is that only the few metres from the box outside to the house, or can the "curb" be in the next suburb?)?


The most recent speed test (4pm): download 0.2Mps, 20mins later latency 20ms 9Mps, 1 min after that latency 362ms download 0.75Mps.  It'd be good to know why such huge changes.





Re: Very slow connection: Is it ADSL or my wireless network?


Lot of thoughts there. 


One of the main reasons the NBn is being rolled out is because of increase population usage. Basically in just a few years so much more is being downloaded all around you. Netflix, etc. Data usage amounts and numbers of homes all asking for more has jumped. Couple with this is the fact very little is now being down to maintain the (already failing) copper network in many areas. I can only say that the NBN can't arrive soon enough for you. 


1) FTTC is generally thought to be the second best NBN option possible (behind FTTP). The Kerb (or Curb) is indeed outside your home and each fibre run will connect to four homes on your street. It should be very fast and reliable.


2) My main tip for diagnosing your hiome equipment is disconnect and turn off all of it except your main modem and PC (connected to each other via wired). Also turn off wifi on this modem while testing. See what speeds you can get then. If you want to try a different modem then switch it around and test it in isolation (again only via cable and with all wifi capability off)


3) Optus do now provide a 5Ghz modem and if you've been a customer for a while then they can send one out on request (for free or a small cost) if you ask. That said, if your cable speeds are limited to 3Mbps then your wifi speeds will not be able to exceed that anyway.


4) Yes there is a lot of hype and blame and complainers (sometimes with good reasons.) FWIW IMO it has largely been the Telcos who have not handle the transition to NBN well and who have tried to take advantage of the confusion in the mean time (e.g. selling mostly useless unlimited 12Mbps plans and skimping on bandwidth purchased from NBNCo).  That said, al lot of that has cleared up now and things are much better (sometimes being last in line is a good thing).


5) Yes FTTC uses the last 25m of existing copper but that will have no effect on your speeds. Current ADSL2+ can located the node (fibre) over five km away. Being withing 25m or so means you can easily do 200Mbps and with a bit of tweaking NBNCo will be releasing 1000Mbps plans on FTTC soon enough. Be very happy you are on FTTC Smiley Happy (as an added bonus there's zero extra installation required in your property)


6) What speed site are you using? Is optus sending out a technician to check the line at your property?




Peter Gillespie

Re: Very slow connection: Is it ADSL or my wireless network?


Hi Peter G


thanks again. It's a pleasure to read reasoned thoughts on issues.  I used Speedsmart on one machine and Ookla on another. Results are comparable.


I have not been in contact with Optus about this issue.  That would be the next step. I just dread ringing or chat: my past experiences have been frustrating.  Maybe I'll be brave and try chat.



Re: Very slow connection: Is it ADSL or my wireless network?


Yes, Optus phone can be a bit of a long wait sometimes.


I would suggest chat for a fairly quick first stop. You'll probably get different suggestions options with a couple of atempts.


They'll step you through the usual reset process etc. Probably send out a replacement modem if that doesn't work.


After the modem you'd be wanting to request they send someone out to test the line locally. Given you have historically got 14 Mbps and even now get say 9 Mbps they should be asking why 3 Mbps now.


There are speed profiles you can be on though, so perhaps ask if you can be put on the more aggressive speed option (this might increase drop outs but also might help speed - they shold be able to do that on the spot)


Note customer service favourite response is they are aware of issues and work is being down to fix them (although no timeline is available). This is basically code for the NBN is coming.


Good Luck


Peter Gillespie

Re: Very slow connection: Is it ADSL or my wireless network?


Hi  an update.


Regular speed monitoring showed that speeds increased over the day from Saturday last, and this week is much better reception than last week, with many fewer low speeds throughout the day and night.  I did nothing to change the internal house system or setup.


All I can assume is that there was a network glitch out there which has now been fixed (might be Optus, might be Telstra/NBN).  Optus has asked me to record that the issue has been solved as a result of a Yes Crowd response.  It wasn't. However, the advice from PeterG was very useful in understanding the situation.




Re: Very slow connection: Is it ADSL or my wireless network?


Glad some of it was useful. Smiley Happy


Seems like there's still room for variation, but fingers crossed the new speeds stick.


Peter Gillespie

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