packet loss - how much classes as "intolerable"?

Greetings all...

we're having horribly bad performance from our (cable modem) broadband during the afternoons and evenings - it works fine during "non-busy" times, like the early hours of the morning - but from late afternoon throughout the evening it's virtually unusable. Weekends are pretty much a no-no, too.

the connection is meant to provide 10Mb/s download and 1Mb/s upload - and indeed, when the network is lightly loaded that's what we are getting

but around 7PM, say, we crawl at something like 300kb/s download in fits and starts - often it's even slower than that, with the line cutting out altogether for many seconds at a time; and 40% packet loss is quite typical

it's the packet loss which is the real bugbear; pages rarely finish loading; if I try to post something at BBS it gets "stuck" halfway through posting and I never know what's actually turned up at the other end; SSL email doesn't even make it through the SSL handshake so we rarely get as far as getting the message statistics from the server, let alone actually sending or receiving anything.

I don't do anything which requires great speed! Of course, it's nicer to go faster - but that's not the point I'm getting at. It's the unreliability which accrues from the awful packet loss which is the "killer ".

from my own experience, 5% packet loss is starting to cause aggro., and when the packet loss gets up to 10% things are starting to get seriously tedious e.g. email is misfiring as often as not. 30% packet loss and email needs ~5 attempts to get a simple message through - which is about the point at which I give up (actually I resort to dialup if something's urgent).

I'd appreciate some views on just how much packet loss could generally be regarded as entirely unsatisfactory - I'm going to be having a go at our ISP about this matter, and some idea of what people would consider simply unacceptable would give me more confidence - particularly if anyone e.g. works for an ISP and has a "yardstick" for this kind of thing. Or is there some kind of accepted standard laid down somewhere?

TIA and best wishes, HJ.

 

HJ,

Can I assume you're with Virgin Media (the only cable supplier in th UK as far as I'm aware)?

I would definitely give them a call particularly during the poor connections (I'm with their 20M/bit service and rarely see less than 17M/bits). Unfortunately the timing may mean that you'll be connected to a foreign call centre which I've found to be less than helpful at the best of times.

Report your issue after 9am and ask a line manager for a call back, with luck you'll keep to a local call centre and they will assist.

Again the above assumes VM. If you're using ADSL then all bets are off

 

Wildfire, thanks for a very useful reply!

Yes, indeed the ISP is Virgin Media - and after my experiences with the (offshore) call centre during the email fiasco last year I think I'll be doing my best to find a different route. The forum looks a much better bet (can actually raise/progress a ticket, and arrange an engineer via the forum) - but upon looking around there I find a depressingly large number of other folks having very similar issues and, it seems that many people are having trouble / waiting a long time to get those issues fixed.

...which is why your reply was particularly valuable, as (of course) at the VM forum I'm only reading from people who are having trouble, so I'm getting a disproportionate view of the situation. It's good to know that it's not that the whole VM network is overloaded!

I've considered ADSL options as an alternative, but found that our "local" exchange is quite a distance away. Besides, I'm very happy with the fibre-optic way of doing things (e.g. during thunderstorms!); and Mrs J. is fond of the TV part of the package.

I've got as far as doing the "pre-flight checks" (Tx and Rx power levels, and SNR are within limits); from what I can tell it seems that the bottleneck is close to me - they suggest doing a tracert to the BBC to help localise faults, and I'm getting packet loss and timeouts between us and the first IP en route working away from us. Interestingly, I note that even when our download performance is dire, our uploading often still functions at full speed - which might fit with an overloaded UBR, I'd guess... if so, we might be in with a chance of getting it fixed relatively easily.

Having been monitoring it over the last week or so, I think that I have enough data to go on to make a pretty convincing case; and if things don't get too hectic work-wise tomorrow I'll start the ball rolling.

Noted! I'll certainly bear it in mind - *if* I can get a local call centre then that's a different kettle of fish. But if I end up with offshore hopelessness again I'll go mental (anyway, all they ever do is get me to reboot everything zillions of times... which in this case simply isn't going to help)

best wishes, HJ.

 

Don't, ADSL cannot compete with cable particularly if your exchange is some distance away. Stick with VM and with luck they'll resolve your issue soon.

Have you asked any neighbours if they're encountering similar issues?

As an aside what make model modem do you have? The older surfboards they used to issue (quite some time ago now) may struggle with the 10Meg connection (I think they topped out at 11).

 

Today wasn't too bad:
- worst packet loss (only) 29% at 19:04
- slowest downstream 0.32Mb/s at 20:05
...which is quite fast for a Sunday evening!

The nearest "neighbour" who's with VM is unfortunately quite some distance away; I left a message to ask them to ring me back for a natter about it, but haven't heard anything yet. I do intend to stick with VM and try to get them to fix it; as you rightly say, ADSL would be a large step backwards - plus we would need to make holes in walls etc to hook up the older 'phone line once more for ADSL.

Not sure what you mean by "surfboard "! - our modem's a little black thing which identifies itself underneath as a Model No. E08C013.00; is this the type which maxes out at 11Mb/s? If so, we might need a swap if they come round to "upgrading" our service to 20Mb/s (which I gather is what's meant to happen - though that sounds like a bit of a bad joke at present).

We stuck with dialup only for quite some time before going over to broadband; the old cable TV box did have an RJ45 socket on it, but I gather that these were awful devices which struggled coping with 2Mb/s broadband and doing the TV at the same time. By the time we went over to broadband VM had replaced the cable TV box with a different model with no ethernet socket, and the broadband connection was effected via a separate modem which looked similar to the one we have today.

The limiting factor at the moment is our router (Belkin FD5231-4) - a bit old, but not wireless (for radio waves have much better things to do! ...it's bad enough having a house full of computers for any sakes). With the router in the way I top out at ~6.7Mb/s down, 1Mb/s up, while connected directly to the cable modem ~10Mb/s down is quite normal at anti-social times e.g. the early hours of the morning. Trouble being, during "normal" times when "normal" people (e.g. Mrs. J. ) want to use the internet, say 7PM, it's virtually unusable. Understandably, she ain't happy...

==

One rather interesting thing that I found through playing around with this: I've tried various "test my connection" websites: speedtest.net, mybroadbandspeed.co.uk and so on, there are plenty to be found. Some of these give a very unrealistic idea of the performance on a spluttery "now you see it, now you don't" connection. They tend to measure the maximum that the connection is capable of, rather than an average - but an average would be far more relevant to my situation, which is very roughly 20% on, 80% off during the early evening.

Like, it takes about an hour to get to London by car from here. What's the point of giving me an estimate of an hour, if the reality of the situation is that I'm going to be stuck in traffic for 4 hours? If I'm trying to download a large file, say, I want to have a yardstick on how long it's going to take to arrive, not how quickly it could arrive under ideal line/network/congestion conditions.

So I've been getting into comparing the various "test my speed" websites to find out which give a realistic estimate. XP's performance monitor (and a firewall which has the ability to "pause" the connection) are excellent for this, and I've just recently discovered how to log the performance monitor results to a text file... working on this, it's an interesting exercise.

==

Hope you're coping with the weather up there, Wildfire - we've had some wicked gusts today, part of the roof overhang of the local Sainsbury's came crashing down and the big letter S from the sign too. Nobody hurt, thank goodness.

best wishes, HJ.

 

No that modems fine, the surfboards were one of the first models they used when 2Mb/s was the fastest connection offered. But...

If you upgrade your service they will upgrade your modem to a SuperHub (Modem & wireless router combined) FOC. Perhaps worth thinking about?

Weather's been fine here HJ, didn't you know Dundee is officially the sunniest place in Scotland (not that that says much)

 

as long as we can disable the wireless part of it! From the pictures I've Googled it looks as though it has 4 ethernet sockets, so there's a fighting chance...

Do you have one of these SuperHubs, pls? - and is it actually OK? I'm reading things like this and thinking that I might well be better off staying just as we are (as long as we can get the connection quality fixed)

(PS added wind damage pictures to earlier post #5)

very best, HJ

 

aha : SuperHub ?= customised Netgear DG480 (crippled some features of UI)

HJ

(9149kb/s, 0%loss)

 

Re your superhub questions.

Yes, basically a four port Ethernet router/cable modem with wireless capability which can be disabled. I've had one for around a month now (since I upgraded) and had no issues with wired or wireless usage.

You could always piggy back your current router if you'd prefer though at the moment there is no way to disable the routing capabilities of the super hub (a firmware upgrade has been rumoured to allow this).

 

Hi Tony

...which I obtained from 192.168.100.1 as you rightly suggest. Although the VM specifications are quite a bit tighter than your figures!

VM Downstream Power spec:
QAM64 (Knowsley networks) : -7 dBmV to +3 dBmV
QAM64 (Langley/Bromley) : -10 dBmV to 0 dBmV
QAM256 : -3 dBmV to +7 dBmV
...we are on QAM256 and showing 3.7 dBmV

VM Upstream Power spec:
40 dBmV to 50 dBmV
...we are showing 42.7dBmV

VM Downstream SNR spec:
64QAM : 29 dB minimum; 32 dB or above desired
256QAM : 32 dB minimum; 35 dB or above is desired
...we are showing 42.1dB

At low network utilisation times the connection performs excellently; but during late afternoon and through the evening we're often better off using the old dialup

Have you any "yardstick" for packet loss, though?

I'm after some idea of a figure for packet loss, past which the connection could be generally be considered as simply unacceptable.

Subjectively, from my recent experiences, 10% is still handleable but getting highly irritating (pages won't load properly and email checks go wrong frequently; basically one has to do everything several times over to get a result) - but when it gets worse than about 40% it's hardly worth persevering.

best wishes, HJ.

 

well, I found a sort-of answer to my question: 100% packet loss is certainly unacceptable, one just doesn't get any internet at all particularly if the "ready" light stays flashing on the cable modem...

yes, our spluttery hit-or-miss broadband finally cut out altogether - so I've been using the internet as little as possible, via a "pay-through-the-nose" dialup connection. Back on again today though, and I'm waiting for 4PM with interest to see what happens, for that's the time we normally hit trouble on weekdays (presumably when the schoolchildren return home).

I've discovered that several other people in our area are also have the same speed / packet loss problem; and also, there seem to be two issues currently logged for our local "chassis" - so I'm thinking that the outage was maybe engineers trying to sort it all out?

The cable modem's diagnostic screens have told quite an interesting story during the outage. Downstream was locked; but upstream kept on ramping the power level, presumably trying to find the correct operating point, but wouldn't lock. The modem was certainly receiving data, because the appearance of the diagnostic pages changed a couple of times; the page width altered; and (rather amusingly) for a while the favicon for the diagnostic pages altered from the normal VM red "tick" to a big blue letter 'n'... so, it seems that while at the VM forums there are several disgruntled customers trying to find a different ISP, our cable modem actually managed to do that all by itself

(don't worry Wildfire, I'm "hanging on in there" and going to give them a decent chance to sort it; actually it's looking positive, at least there are signs that they are now "on the case ")

best wishes, HJ.

 

typical examples of diurnal variation before outage, after outage

(orange background = via router which limits us to ~6.5Mb/s; not that it makes a lot of difference when the line limits us to less!)

...so, little if any real improvement.

That shouldn't be taken as typical of VM broadband as a whole - as Wildfire says, much of the network is performing fine.

best wishes, HJ