Broadband performance

[Auric]

Hello Community,

I have contracted for an FTTC 80/20 line, expecting a capped 17a profile.

After extensive speed testing over the last month I have determined that the modem has stabilised (no resynchs) at 43/8, ping latency c. 12 msec. My device to router connection is gigabit Ethernet. I’d like to establish if 43/8 is the best achievable bit rate for my loop and what the issues are to attaining a higher bit rates be it: line length, bridge tap(s), line cross talk, REIN or second-rate modem performance.

My router is a 2013 design using a Lantiq chipset.

My line is on the Bury St Edmunds (BSE) exchange and is served by cabinet 31.

I’d like guidance on how to find out the following information:

1. Location / address of BSE cabinet 31;
2. Manufacture of cabinet. Huawei / ECI.
3. Is the cabinet enabled for VDSL2 vectoring?
4. Will further investment improve performance, e.g. another router?

Thanks.

[licquorice]

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@Auric wrote:

Hello Community,

I have contracted for an FTTC 80/20 line, expecting a capped 17a profile.

After extensive speed testing over the last month I have determined that the modem has stabilised (no resynchs) at 43/8, ping latency c. 12 msec. My device to router connection is gigabit Ethernet. I’d like to establish if 43/8 is the best achievable bit rate for my loop and what the issues are to attaining a higher bit rates be it: line length, bridge tap(s), line cross talk, REIN or second-rate modem performance.

My router is a 2013 design using a Lantiq chipset.

My line is on the Bury St Edmunds (BSE) exchange and is served by cabinet 31.

I’d like guidance on how to find out the following information:

1. Location / address of BSE cabinet 31; I can't see a number on the cab on Google street view, but suspect it is 31, on the corner of Barons Rd and Rembrandt way
2. Manufacture of cabinet. Huawei / ECI. Huawei
3. Is the cabinet enabled for VDSL2 vectoring? No idea, but doubtful as not a huge number of cabs were enabled.
4. Will further investment improve performance, e.g. another router?

Thanks.

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Can you post your router stats and the the checker results from your phone number here https://www.broadbandchecker.btwholesale.com/#/ADSL

[Auric]

Thank you licquorice

From BT Broadband (btwholesale.com)

                                                    Downstream (Mbps)            Upstream (Mbps)        

VDSL Range A (Clean)               57        36.7                        12.6     8.2                      

VDSL Range B (Impacted)        55.5     35                        12.5     7.4                  

From router stats:

Data rate:                         8959 / 47505

Maximum data rate:      8959 / 48283

Noise margin:                   6.2 / 3.7

Line attenuation:           30.3 / 21.0

Signal attenuation:        29.9 / 18.6

Modulation:                     G.993.2 Annex B

Cheers.

[licquorice]

A screenshot of the checker would reveal further information, but at first glance you are getting about as good as your line will support, 47M.

Any improvements to be made would be marginal and unnoticeable in day to day use in any case.

[Auric]

Thanks licquorice.

Screen shot attached.

[imjolly]

From the router stats you have posted your connection speed is virtually at attainable and with anoise margin of 3.7db you already have received the boost from the DLM activating G.INP

[Auric]

Thanks  imjolly

1. I understand that the operating noise margin target is 3dB. I believe that these are however measurements made by the modem. Could they change change with different hardware?
2. Why is there such a wide spread in attainable and actual performance? The BT availability checker suggests that 55 to 57 Mbps is possible. My line is running c 25% down on that.
3. The upstream margin is reported at 6.2 dB. Why is my Mbps at 8.0?

Cheers.

[licquorice · Accepted solution]

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@Auric wrote:

Thanks  imjolly

1. I understand that the operating noise margin target is 3dB. I believe that these are however measurements made by the modem. Could they change change with different hardware? No
2. Why is there such a wide spread in attainable and actual performance? The BT availability checker suggests that 55 to 57 Mbps is possible. My line is running c 25% down on that. No, the checker estimates your speed between 57 and 35. It is just an estimate and you are in the middle of the range.
3. The upstream margin is reported at 6.2 dB. Why is my Mbps at 8.0? Because that is the fastest speed your upstream is capable of due to different frequencies usedfor upstream and downstream.. Upstream target margin is 6dB not 3 dB like downstream.

Cheers.

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