Bitswap & Sra

[chris878]

Does Openreach support BitSwap, & SRA?

I could see it causing an issue, if Bitswap wasn't supported at my cabinet, as dlm is the only responsible thing to make adjustments to your line. Not Bitswap or SRA.

[cookiemonsteruk]

@chris878 

Sra was apparently trialled on 200 lines from huawei cabinets in 2018.  Can't find any reference to the outcome.  On 3rd party routers the main one to use is "attempt to log in with g.inp " should be ticked as it bring noise margin down from 6db to 3db and maybe 10Mbps more speed.

Other options to consider on asus are :-

1. DSL Modulation

You can choose a proper modulation type. If you do not know it exactly, please leave it as "Auto Sync-Up" (Default value).

02. ANNEX Mode

Please ask for your ISP which Annex mode your line is. If you are not sure, please try to set "A/I/J/L/M" firstly. If DSL LED is not flashing after 60 seconds, please set to "B/J" and try again.

03. Dynamic Line Adjustment (DLA)

This item allows system to monitor the DSL line and it's designed to maintain stability of the line. Based on current line condition, necessary changes will be adopted. However, if you want to configure settings by yourself, please set it to "Disabled".

04. Stability Adjustment (ADSL)

This is for ADSL mode. You can set negative value to for better stability and positive value to for better performance. Unless your line is very stable, otherwise, we suggest you don't set a high positive value. Note that this item will be adjusted automatically if “Dynamic Line Adjustment (DLA)” is enabled.

05. Rx AGC GAIN Adjustment (ADSL)

This item configures Rx AGC (Auto Gain Control) GAIN for ADSL if ADSL connection is still unstable after tweaking the Stability Adjustment (ADSL) setting and has some CRC then could set to Stable mode.

06. Stability Adjustment (VDSL)

This item allows you to tweak the target SNR Margin of VDSL.

Please go to "System Log - DSL Log", find downstream SNR Margin firstly.

For instance,with a downstream SNR Margin at 8dB, you could set to 7dB or lower to maximize the downstream performance, 4dB (Max. performance) but please note the lower value it is, DSL modem router will be weaker to defend the line noise.Therefore, interruption might occur so please adjust with proper value. However, if VDSL connection is unstable or unable to establish a connection, for this case then set to a higher value such as 9dB ~ 30dB.

07. Rx AGC GAIN Adjustment (VDSL)

This item configures Rx AGC (Auto Gain Control) GAIN for VDSL, if tweak the Stability Adjustment (VDSL) setting still could not get desired downstream.Try to set Rx AGC GAIN Adjustment to High Performance mode. However, if your VDSL connection is unstable and has some CRCs then could set to Stable mode.

08. UPBO - Upstream Power Back Off (VDSL)

This item allows you to control whether to Enable/Disable UPBO (Upstream Power Back Off) for VDSL. DSLAM could use UPBO to reduce the Tx Power of your xDSL modem router. In some cases,abnormal UPBO control from DSLAM could lead to sync up issue (such as no enough Tx Power to sync with minimum rate). Thus with this feature now you could disable UPBO and won’t get affected by DSLAM setting.

09. ESNP - Enhanced Sudden Noise Protection (VDSL)

This command is helpful for some impulse noise environment and to enhance line stability. Note that this item will be adjusted automatically if “Dynamic Line Adjustment (DLA)” is enabled.

10. SRA (Seamless Rate Adaptation)

Enable SRA (Seamless Rate Adaptation) for consistent data transfer rates and to prevent weak and lower connection but down/up speed would be somewhat decreased.

However, if your connection is very stable and you notice a drop in download or upload speed, you can disable SRA.

11. Bitswap (ADSL)

This item enables Bitswap feature. It adjusts bits allocated for bins/channels.

Busy or congested bins/channels are assigned fewer bits while available channels are allocated more bits to handle.

12. Bitswap (VDSL)

This item enables Bitswap feature. It adjusts bits allocated for bins/channels.

Busy or congested bins/channels are assigned fewer bits while available channels are allocated more bits to handle.

13. VDSL Profile

This item configures VDSL Profile to be used for VDSL, and its default is 30a multi-mode which is compatible to 17a/12a/8a mode. However , in order to work around the non-standard 30a multi-mode VDSL DSLAM sync issue, which deployed by some of Germany ISP, set to 17a multi-mode might be needed in order that the VDSL line to sync up. For users of other regions, there is no need to change this setting. 8a multi-mode implies 8a, 8b, 8c, and 8d ;12a multi-mode implies 12a and 12b.

14. G.INP (G.998.4)

G.INP stands for Impulse Noise Protection. It works on ADSL2, ADSL2+, and VDSL2 only. It is enabled to provide enhanced protection against impulse noise or to increase the efficiency of providing impulse noise protection. If your DSLAM does not support it, please disable it.

15. G.vector (G.993.5)

With G.vector, crosstalk among the signals in the same cable could be cancelled, such as far-end crosstalk (FEXT). It significantly improves Signal-to-Noise Ratio (SNR) that leads to higher achievable bit rates. However ISP must deploy vectored VDSL2 DSLAM for this feature to work. If you find it doesn't work well or you know the G.vector of your ISP is non-standard, please enable both of this option and Non-standard G.vector.

16. Non-standard G.vector (G.993.5)

This item supports Non-standard G.vector for specific regions. Please note if you know the G.vector of your ISP is standard, please Do NOT enable this option for optimized performance.

[chris878]

seems like a lot of these settings you have listed, are not found on tp link routers.

"attempt to log in with g.inp " should be ticked"

I dont seem to have that option on my router.

I thought having bitswap enabled could conflict with the dlm.

[cookiemonsteruk]

@chris878 

Possibly, the trial on sra referred to it being conducted with dlm off. I would assume that means nothing came of it as dlm gets you down to 6db and g.inp to 3db also thru dlm. I would leave them unticked even if the cabinets aren't actually using them.  There should be reference to g.inp somewhere unless its automatically enabled

[chris878]

okay, i will leave sra unticked, but what about bitswap?

[cookiemonsteruk]

@chris878 

Do the same leave unticked/disabled. these 3rd party routers are made for large areas ie europe so have include all options even in countries that don't use them.  

[Chrisee]

@chris878 if you really want to know what Openreach support try reading this document which goes into depth on how Openreach FTTC works. Now I do not pretend to understand more than 10% of what that is saying (the forum member who knows the most will be @mae-3)

However in my limited experience there is minimal gain in playing with modem settings on the basis if it ain't broke don't fix it as the default settings on a unit sold for the UK market will be optimised. @cookiemonsteruk is correct that many modem routers are designed for many markets so many of the settings are not relevant to the Openreach VDSL service which uses profile 17a.