FAO: CRT -- ECI Modem Latency Problem with G.INP

[#1]

Quote from: Melancholie

8ms each way

I'm afraid I don't understand that. Aren't ICMP ping times R(ound)T(rip)T(ime)s?
It looks as if incompatible firmware may very well cause an interleaved profile to be applied in error, however, yes.
As goldenfibre says, G.INP isn't causing an increase in latency for everyone. Sometimes just the opposite, in fact.
Switching the modem off for an hour or so yesterday didn't persuade it to update itself with any new firmware as far as I can tell (no change in latency anyway).
Hence the need to ask the Customer Relations Team about it.
I could always buy a Huawei modem (and then even get myself some line stats into the bargain,) but frankly I can do without the hassle.

[#2]

My ping with G.INP enabled:
Microsoft Windows [Version 6.1.7601]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.
C:\Windows\System32>tracert www.bbc.co.uk
Tracing route to www.bbc.net.uk [212.58.244.71]
over a maximum of 30 hops:
  1    <1 ms    <1 ms    <1 ms  home.gateway.home.gateway [192.168.1.254]
  2    10 ms    10 ms    10 ms  lo0.10.central10.pcl-bng01.plus.net [195.166.130
.138]
  3    17 ms    11 ms    11 ms  irb.10.PCL-CR01.plus.net [84.93.249.81]
  4    11 ms    11 ms    11 ms  ae1.ptw-cr01.plus.net [195.166.129.0]
  5    11 ms    11 ms    11 ms  kingston-gw.thdo.bbc.co.uk [212.58.239.6]
  6    *        *        *    Request timed out.
  7    *        *        *    Request timed out.
  8    11 ms    11 ms    11 ms  ae0.er01.telhc.bbc.co.uk [132.185.254.109]
  9    12 ms    12 ms    12 ms  132.185.255.149
10    11 ms    11 ms    11 ms  www.bbc.co.uk [212.58.244.71]
Trace complete.
C:\Windows\System32>

[#3]

Interleave is applied on upstream and downstream, it doesn't have to be applied on both. The modem stats indicate how much delay has been applied to each path.
Round trip time is a combination of a there and a back - the there and the back can have different delays due to interleave.

[#4]

Sorry, Melancholie, I'd prefer to diplomatically ignore the above, but it is bunkum and that needs to be pointed out lest others repeat it. So this is just a quick post to do that.

[#5]

Quote from: InterZoom

It looks as if incompatible firmware may very well cause an interleaved profile to be applied in error, however, yes.

It's neither of those.
An incompatible firmware would mean the modem does not connect to the DSLAM.
We know from the GEA Circuit Tests, interleaving is also not being applied because they are coming up as error protection off (unless the tests are not correctly reporting the DLM status). I've seen a couple of examples of the same latency increase as yours, but the systems show the line is on fast path ds and us.

[#6]

Quote from: InterZoom

Sorry, Melancholie, I'd prefer to diplomatically ignore the above, but it is bunkum and that needs to be pointed out lest others repeat it. So this is just a quick post to do that.

Oh, which part?
That interleave can be applied independently to upstream and downstream paths or that RTT is a combination of upstream and downstream latency?
I'd prefer it if you simply correct me if I'm wrong rather than claiming what I wrote is 'bunkum' without explanation.

[#7]

@AndyH
Just to be clear, I'm not claiming any special knowledge of the detailed mechanism of this issue at all: "may very well" is purely speculative.
I'm merely asking the Customer Relations Team whether they can do anything about it, or whether I simply need to wait for a new firmware version to be pushed out by BT (and for confirmation that that is going to happen).
@Melancholie
You sounded as if you were stating facts. Sorry I didn't have time for more.
Interleaving can be applied separately to the upstream and downstream, however the interleave delay is not the same thing as the increase in latency due to interleaving.
The RTT of an ICMP ping is the time it takes to receive an echo reply packet from the target in response to the echo request packet sent to it. It includes all of the latency along the outward and return network paths -- which may be different and have different delays on them quite apart from that introduced by the particular "final mile" technology.
It isn't possible to separate the RTT into "there and back" components because there won't normally be a timestamp on the reply packet.
Possibly I misinterpreted what you were saying and this is actually what you meant. If so, my apologies.

[#8]

I'm aware of what a ping is and how it works.
I'm confused by a statement there and disagree with it as I am quite sure it's wrong but will leave it be as not relevant.

[#9]

I took the short route early on and got one from the usual outlet, I see you are also on a Huawei Cab with ECI Modem then.
Good luck with your quest, Mr Zoom



Best Regards....

[#10]

Yeah, short is good. And effective self-help better than fruitless back-n-forth any day. These things can drag on, as you know...
Posting the info about what I'm seeing perhaps helps to add something to the collective picture, though, so worth doing.
I'm still kind of hoping a firmware update will mean I never have to see my modem stats! I really like the 40/20 product, to be honest, because I never have to concern myself with the sync speed, which is way above the fixed profile cap on such a short line, and the latency was only a couple of ms higher than FTTP. Leaves me free to focus on putting the rest of the world to rights!!!   
Anyway, it's very nice to hear from you, Mr. Binary. Careful you don't get drawn into the mathematics of interleave delay. Linger 8ms too long and you're done for! 

[#11]

Another long thread, this time at thinkbroadband commenting on G.INP and ECI modems:
http://forums.thinkbroadband.com/fibre/4398643-ginp-or-interleaving.html?fpart=all

Has anyone seen any comment posted on any forum to say that their ECI modem is working fine, connected to a Huawei cabinet which has been upgraded to support G.INP ?

[#12]

Im on ECI modem to Huawei cabinet and currently im down 10meg on usual speed. PlusNet support tried lying and fobbing me off Saturday, but I know a line stable over 2 years at 73 meg doesn't lose 10 meg in a week when this G.INP rubbish is being pushed out.

[#13]

I had the same issue eci modem on huawei cabinet download dropped from 75 to 65 on Thursday last week, seen all these posts and also saw no sign of fix from BT. I brought a huawei modem flashed to sp08 firmware and speed came straight back, so if you need a quick fix head over to eBay and pick up a modem.
Sheepdog

[#14]

I feel the Zoom feels the need to bite the splinter out over a period of time rather than just pull it out... Any news yet ?
I'm curious as my ECI may need attention at some point!

[#15]

@Sheepdog which ebay seller did you get your huawei modem from? did notice they have some BT modems on amazon but doesn't state if they are ECI or huawei.