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Author Topic: How big is your G.INP DTU ?  (Read 988 times)

Weaver

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How big is your G.INP DTU ?
« on: September 26, 2020, 08:55:07 PM »

Questions for those of you who have G.INP. I donít know anything about the subject, just trying to understand- I am in the middle of reading the standards doc. I have PhyR rather than true G.INP and my modems do not list the G.INP standard parameters unfortunately, so I donít have enough information to allow me to derive the DTU size. Perhaps someone who has a full stats listing will help.

See also https://forum.kitz.co.uk/index.php/topic,21823.msg376621.html#msg376621
I would be interested to see how much people differ.
« Last Edit: September 26, 2020, 09:11:51 PM by Weaver »
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Weaver

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Re: How big is your G.INP DTU ?
« Reply #1 on: September 27, 2020, 03:25:11 PM »

I tried a search through old forum posts, which wasnít easy, but I found this stats listing: https://forum.kitz.co.uk/index.php/topic,19056.msg339032.html#msg339032

That gives Q = 8 and N = 248 so DTUsize = Q * N = 8 * 248 = 1984 bytes. Is that correct?

Why the variation? I can understand why it needs to vary to follow the different RS-coded block sizes (ie block that includes R bytes appended) That is roughly double the 960 bytes calculated in the first post linked to (from my previous post).

I would have thought that a large DTU size is a bad thing? Dial-up modems IIRC only use a small DTU size in order to guard against the possibility of a packet never getting through because it gets corrupted and then so does its retransmitted copy, and the next, etc etc. Also a small DTU can be transmitted quickly and that part of the original packet has a lower probability of being corrupted; in fact the only bad thing is the header overhead on the DTU.
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Weaver

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Re: How big is your G.INP DTU ?
« Reply #2 on: September 30, 2020, 05:10:39 AM »

Would anyone be willing to post their stats in this thread?
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siofjofj

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Re: How big is your G.INP DTU ?
« Reply #3 on: September 30, 2020, 07:12:38 AM »

Hi Weaver,

I will, since I'm in the relatively rare situation of having actual G.INP on ADSL2+ so you might find this useful. However, it will have to wait until the weekend as my ISP wants to keep monitoring their supplied router (no stats output) this week after Openreach fixed a fault .
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Weaver

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Re: How big is your G.INP DTU ?
« Reply #4 on: September 30, 2020, 10:42:37 AM »

Excellent. Who's your ISP and what is your modem?
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siofjofj

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Re: How big is your G.INP DTU ?
« Reply #5 on: September 30, 2020, 11:41:14 AM »

Excellent. Who's your ISP and what is your modem?
My ISP is NowTV and I am connected to Sky's MSAN (Broadcom chipset) in the LCCAF exchange. I'm currently using the supplied ER115 modem/router, but will be switching back to my TP-Link Archer VR600v1 (BCM63168 chipset) this weekend. I have unlocked the VR600, so can get the same stats you get from your Zyxel VMG1312-B10As.
« Last Edit: September 30, 2020, 11:43:39 AM by siofjofj »
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siofjofj

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Re: How big is your G.INP DTU ?
« Reply #6 on: October 03, 2020, 10:11:37 AM »

Here are my stats from my NowTV / Sky ADSL connection with G.INP on the downstream (despite many DLM interventions during my fault I have never seen upstream G.INP). The MSAN in the exchange reports ChipSet Vendor Id: BDCM:0xa474

Code: [Select]
xdslctl info --stats
xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    8000
Last initialization procedure status:   0
Max:    Upstream rate = 1200 Kbps, Downstream rate = 22173 Kbps
Bearer: 0, Upstream rate = 1117 Kbps, Downstream rate = 21495 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:       L0
Mode:                   ADSL2+ Annex A
TPS-TC:                 ATM Mode(0x0)
Trellis:                U:ON /D:ON
Line Status:            No Defect
Training Status:        Showtime
                Down            Up
SNR (dB):        3.1             9.3
Attn(dB):        20.0            12.3
Pwr(dBm):        18.6            12.1

                        ADSL2 framing
                        Bearer 0
MSGc:           -6              28
B:              245             62
M:              1               1
T:              0               1
R:              6               10
S:              0.0000          1.9211
L:              5110            304
D:              1               16
Q:              2               0
V:              0               0
RxQueue:                38              0
TxQueue:                19              0
G.INP Framing:          18              0
G.INP lookback:         19              0
RRC bits:               0               0
                        Bearer 1
MSGc:           28              -6
B:              0               0
M:              16              0
T:              1               0
R:              16              0
S:              32.0000         0.0000
L:              8               0
D:              1               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
SF:             0               998804
SFErr:          0               0
RS:             505569608               735627
RSCorr:         439             123
RSUnCorr:       0               0
                        Bearer 1
SF:             2933199         0
SFErr:          0               0
RS:             6233045         0
RSCorr:         28              0
RSUnCorr:       0               0

                        Retransmit Counters
rtx_tx:         143655881               0
rtx_c:          574             0
rtx_uc:         0               0

                        G.INP Counters
LEFTRS:         0               0
minEFTR:        21489           0
errFreeBits:    16302497                0

                        Bearer 0
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    2527792104              131366693
Data Cells:     37881010                2220661
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               0
SES:            0               0
UAS:            379             379
AS:             49864

                        Bearer 0
INP:            29.00           2.00
INPRein:        0.00            0.00
delay:          0               8
PER:            0.00            16.32
OR:             0.01            16.65
AgR:            19875.69        1045.34

                        Bearer 1
INP:            8.00            0.00
INPRein:        8.00            0.00
delay:          8               0
PER:            17.00           0.01
OR:             16.00           0.01
AgR:            15.93   0.01

Bitswap:        12697/12697             1/1

Total time = 13 hours 57 min 23 sec
FEC:            439             123
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            379             379
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           0
Latest 15 minutes time = 12 min 23 sec
FEC:            3               0
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           0
Previous 15 minutes time = 15 min 0 sec
FEC:            9               0
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           N/A
Latest 1 day time = 13 hours 57 min 23 sec
FEC:            439             123
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            379             379
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           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
Retr:           0
Since Link time = 13 hours 51 min 3 sec
FEC:            439             123
CRC:            0               0
ES:             0               0
SES:            0               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            0               0
Retr:           0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
« Last Edit: October 03, 2020, 11:07:07 AM by siofjofj »
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kitz

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Re: How big is your G.INP DTU ?
« Reply #7 on: October 04, 2020, 07:11:20 AM »

Would anyone be willing to post their stats in this thread?

If you ever need any stats for comparison, my live stats are viewable from https://kitz.co.uk/linestats/index.htm

The page you are wanting is
https://kitz.co.uk/linestats/fullstats.htm

Please note due to me suffering from a daily SHINE defect that usually only lasts a few seconds but is fine the rest of the day, it normally does OK as far as DLM is concerned before G.INP as it causes few errored seconds.   
Not so good with G.INP though and DLM has 'penalised' the line by setting the profile to re-tx high and gradually kept banding my sync speed down to 60Mbps. 
Suspect the DLM may use LEFTRs and SEFTRs as opposed to ErrSecs/SES to monitor lines with retransmission.
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kitz

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Re: How big is your G.INP DTU ?
« Reply #8 on: October 04, 2020, 07:14:16 AM »

Here are my stats from my NowTV / Sky ADSL connection with G.INP on the downstream (despite many DLM interventions during my fault I have never seen upstream G.INP). The MSAN in the exchange reports ChipSet Vendor Id: BDCM:0xa474

From memory upstream G.INP is not defined in the standards for ADSL2+.
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Weaver

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Re: How big is your G.INP DTU ?
« Reply #9 on: October 05, 2020, 04:51:15 PM »

Thanks for the link Lesley, I had forgotten.
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