Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: Weggy on September 05, 2018, 08:37:19 PM

Title: Interleaving - Is it on?
Post by: Weggy on September 05, 2018, 08:37:19 PM
Hi,

I'm with BT and I have the EchoLife HG612. I understand that "Interleaving" could effect my latency in a negative way (I want low latency). Is there a way I can check this?

In addition, could anyone outline what I might need to check for having poor latency (over 300ms) when my line is suffering from bufferbloat / fully loaded.

Many Thanks!

Later Addition...
I've just read the following line on the BT web site "Interleaving can't be switched off for fibre-based broadband lines (such as Ultrafast Fibre or Superfast Fibre). But you can ask for it to be switched off on ADSL (copper) broadband lines - although we don't recommend this." http://bt.custhelp.com/app/answers/detail/a_id/8547/~/what-is-interleaving%3F-what-are-its-pros-and-cons%3F-can-i-ask-for-it-to-be

I assume this is true? If so given my "Superfast Fibre 2 Unlimited" package, I have no option here?
Title: Re: Interleaving - Is it on?
Post by: burakkucat on September 05, 2018, 09:05:50 PM
Welcome to the Kitz forum.  :)

Later Addition...
I've just read the following line on the BT web site "Interleaving can't be switched off for fibre-based broadband lines (such as Ultrafast Fibre or Superfast Fibre).

 . . .

I assume this is true? If so given my "Superfast Fibre 2 Unlimited" package, I have no option here?

Yes, that is correct. There is a DLM process which constantly monitors the service and will adjust various circuit parameters to ensure stability & best throughput speed.
Title: Re: Interleaving - Is it on?
Post by: j0hn on September 06, 2018, 07:02:31 AM
Quote
Is there a way I can check this?

Have you unlocked the HG612 to gain access its stats?
Title: Re: Interleaving - Is it on?
Post by: Weggy on September 06, 2018, 08:36:10 AM
Have you unlocked the HG612 to gain access its stats?

Yes I have but I don't know where I need to be looking :)
Title: Re: Interleaving - Is it on?
Post by: Weggy on September 06, 2018, 08:38:54 AM
Welcome to the Kitz forum.  :)

Yes, that is correct. There is a DLM process which constantly monitors the service and will adjust various circuit parameters to ensure stability & best throughput speed.

Yea this is the thing. My snr margin is 19 and I'm wondering if this adjustment while improving my speed has negatively effected my latency. I have a major issue playing games when someones using the line in a spike manner for example netflix. My bufferbloat rating is A on dslreports so I dont see what else I can do.

Here's a long thread outlining me trying to fix the issue from my router with no luck: https://www.snbforums.com/threads/qos-and-ping-in-dota-2-please-help-me.48548/page-5
Title: Re: Interleaving - Is it on?
Post by: jelv on September 06, 2018, 09:24:05 AM
If you had a perfect line with latency of 1ms that would not cure the problem of latency spikes when someone else is using all the line capacity!

You need to be looking at limiting the ability of others to saturate the line.
Title: Re: Interleaving - Is it on?
Post by: johnson on September 06, 2018, 09:56:09 AM
From the thread you say you have an Asus RT-AC5300, have you tried the merlin firmware (https://asuswrt.lostrealm.ca/)? It appears to support fq_codel (https://github.com/RMerl/asuswrt-merlin/wiki/QoS-Queue-Disciplines) and so could fix your lag during usage spikes. I have no experience of asus routers or merlin, but SQM in openwrt fixes the exact issue you are experiencing, so if merlins implementation of it is functional it should do the same.

If you have tried this (sorry I didnt read the whole 5 page thread you linked), try reducing the ingress and egress values you give the SQM settings in merlin. I have known the bufferbloat tests on dslreports to show A+ when there was still significant spikes in latency when using full bandwidth of the connection. Try a heavily multistream download (torrent a linux iso) and monitor your ping to a stable server yourself.
Title: Re: Interleaving - Is it on?
Post by: j0hn on September 06, 2018, 05:25:27 PM
To answer your original question (tell if the line is interleaved) you'll need to telnet in to the HG612 and issue the command xdslcmd info --stats and post the results here.

Alternatively you could install DSLStats (http://dslstats.me.uk) and configure that for the HG612 and post the results of the 1st Telnet tab.
Title: Re: Interleaving - Is it on?
Post by: Weggy on September 06, 2018, 06:16:55 PM
To answer your original question (tell if the line is interleaved) you'll need to telnet in to the HG612 and issue the command xdslcmd info --stats and post the results here.

Alternatively you could install DSLStats (http://dslstats.me.uk) and configure that for the HG612 and post the results of the 1st Telnet tab.

Code: [Select]
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status:   0
Max:    Upstream rate = 11506 Kbps, Downstream rate = 49884 Kbps
Bearer: 0, Upstream rate = 11394 Kbps, Downstream rate = 51638 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:       L0
Mode:                   VDSL2 Annex B
VDSL2 Profile:          Profile 17a
TPS-TC:                 PTM Mode(0x0)
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        2.9             6.6
Attn(dB):        19.7            0.0
Pwr(dBm):        12.7            7.4
                        VDSL2 framing
                        Bearer 0
MSGc:           -6              26
B:              227             237
M:              1               1
T:              0               51
R:              12              16
S:              0.1404          0.6641
L:              13672           3060
D:              4               1
I:              240             127
N:              240             254
Q:              4               0
V:              0               0
RxQueue:                126             0
TxQueue:                21              0
G.INP Framing:          18              0
G.INP lookback:         21              0
RRC bits:               0               24
                        Bearer 1
MSGc:           122             -6
B:              0               0
M:              2               0
T:              2               0
R:              16              0
S:              8.0000          0.0000
L:              32              0
D:              1               0
I:              32              0
N:              32              0
Q:              0               0
V:              0               0
RxQueue:                0               0
TxQueue:                0               0
G.INP Framing:          0               0
G.INP lookback:         0               0
RRC bits:               0               0
                        Counters
                        Bearer 0
OHF:            0               1925398
OHFErr:         0               34
RS:             2366465380              4144516
RSCorr:         1165316         157
RSUnCorr:       0               0
                        Bearer 1
OHF:            5192715         0
OHFErr:         0               0
RS:             41541229                0
RSCorr:         37              0
RSUnCorr:       0               0

                        Retransmit Counters
rtx_tx:         46408700                0
rtx_c:          2067            0
rtx_uc:         0               0

                        G.INP Counters
LEFTRS:         0               0
minEFTR:        51640           0
errFreeBits:    65678068                0

                        Bearer 0
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    3987697595              0
Data Cells:     86344740                0
Drop Cells:     0
Bit Errors:     0               0

                        Bearer 1
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    0               0
Data Cells:     0               0
Drop Cells:     0
Bit Errors:     0               0

ES:             0               33
SES:            0               0
UAS:            26              26
AS:             83409

                        Bearer 0
INP:            58.00           0.00
INPRein:        1.00            0.00
delay:          0               0
PER:            0.00            8.49
OR:             0.01            30.11
AgR:            51751.44        11424.35

                        Bearer 1
INP:            2.00            0.00
INPRein:        2.00            0.00
delay:          0               0
PER:            16.06           0.01
OR:             63.75           0.01
AgR:            63.75   0.01

Bitswap:        52929/52929             1661/1661

Total time = 23 hours 10 min 35 sec
FEC:            1165316         157
CRC:            0               34
ES:             0               33
SES:            0               0
UAS:            26              26
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 15 minutes time = 10 min 35 sec
FEC:            8439            1
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 15 minutes time = 15 min 0 sec
FEC:            11083           8
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Latest 1 day time = 23 hours 10 min 35 sec
FEC:            1165316         157
CRC:            0               34
ES:             0               33
SES:            0               0
UAS:            26              26
LOS:            0               0
LOF:            0               0
LOM:            0               0
Previous 1 day time = 0 sec
FEC:            0               0
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Since Link time = 23 hours 10 min 7 sec
FEC:            1165316         157
CRC:            0               34
ES:             0               33
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Title: Re: Interleaving - Is it on?
Post by: underzone on September 06, 2018, 06:24:47 PM
The answer is no, you are not interleaved. You have g.inp activated and a 3dB profile.
Title: Re: Interleaving - Is it on?
Post by: Weggy on September 06, 2018, 06:33:37 PM
The answer is no, you are not interleaved. You have g.inp activated and a 3dB profile.

My next dumb question. What does this mean HAHA Is 3dB good or bad?
Title: Re: Interleaving - Is it on?
Post by: re0 on September 06, 2018, 07:13:47 PM
My next dumb question. What does this mean HAHA Is 3dB good or bad?
G.INP is just a form of retransmission that differs from "traditional methods" (RS encoding/FEC) and has a lower overhead associated as it does not constantly transmit redundant data (only on request when there has been a noise burst that has errored data).

3 dB is indeed good if you like more speed. ;) This implies that the noise margin between [background] interference and your connection has been reduced to allocate more bits. As long as your connection is stable then this should remain.
Title: Re: Interleaving - Is it on?
Post by: Weggy on September 06, 2018, 07:25:30 PM
G.INP is just a form of retransmission that differs from "traditional methods" (RS encoding/FEC) and has a lower overhead associated as it does not constantly transmit redundant data (only on request when there has been a noise burst that has errored data).

3 dB is indeed good if you like more speed. ;) This implies that the noise margin between [background] interference and your connection has been reduced to allocate more bits. As long as your connection is stable then this should remain.

I like speed, but I much much much prefer low latency. Is it good for that?
Title: Re: Interleaving - Is it on?
Post by: jelv on September 06, 2018, 07:37:34 PM
I like speed, but I much much much prefer low latency. Is it good for that?

Depends. If pushing the line results in more errors it could be worse than increased latency.
Title: Re: Interleaving - Is it on?
Post by: johnson on September 06, 2018, 10:18:05 PM
I like speed, but I much much much prefer low latency. Is it good for that?

To be clear, none of the line details we are talking about here will have a noticeable effect on gaming. The spikes to 100s of ms you get when others are using your connection will though, and is what you should try and fix if gaming performance matters to you.
Title: Re: Interleaving - Is it on?
Post by: re0 on September 06, 2018, 10:55:14 PM
Any line that is "fully loaded" will be subject to bufferbloat. If you implemented Quality of Service (QoS) on the network then you could reduce bufferbloat by giving an overhead (therefore you are no longer utilising the line fully). If QoS implementation is not possible then, assuming there are multiple users, you will need to ask every other user to play nicely and manually limit download and upload speeds on their devices.

If the line is not "fully loaded" (and any applicable network hardware is not utilised fully) but is still suffering from high latencies with the inclusion of deteriorated networks speeds then it is probably congestion on the ISPs network. It is fairly unlikely to be your line unless it was a fault, and the DLM would have taken corrective measures at this point to stabilise the line.
Title: Re: Interleaving - Is it on?
Post by: j0hn on September 07, 2018, 12:41:45 AM
You have no add latency like added by interleaving.
You have retransmission (aka G.INP) which adds no latency and any corrupt data is retransmitted by the DSLAM (for downstream, your modem does the upstream).

See here: https://kitz.co.uk/adsl/retransmission.htm

Depending on your location in the country and the ISP routing involved your "ping" to uk sites should be in the region of 10-20ms.
Those nearer London or on brilliant ISP routing can have 5ms pings.

In Central Scotland the lowest ping I've seen on a domestic FTTC line is 15.1ms.
Scottish highlands can be 20ms+.
The further North you go the higher the ping (generally) as most ISP's go through London.

Low interleaving adds 8ms on FTTC.

What is your lowest ping to the wider internet?
Title: Re: Interleaving - Is it on?
Post by: Weggy on September 09, 2018, 01:47:59 PM
Any line that is "fully loaded" will be subject to bufferbloat. If you implemented Quality of Service (QoS) on the network then you could reduce bufferbloat by giving an overhead (therefore you are no longer utilising the line fully). If QoS implementation is not possible then, assuming there are multiple users, you will need to ask every other user to play nicely and manually limit download and upload speeds on their devices.

If the line is not "fully loaded" (and any applicable network hardware is not utilised fully) but is still suffering from high latencies with the inclusion of deteriorated networks speeds then it is probably congestion on the ISPs network. It is fairly unlikely to be your line unless it was a fault, and the DLM would have taken corrective measures at this point to stabilise the line.

You say this but this isnt really what the problem is. If my line is constantly fully loaded, I dont have a problem. Its only when my line receives high load spikes (streaming) that I get an issue.