TalkTalk Wholesale Line Profiles: Difference between revisions

[[File:Tt-profile-list.png|none|frame|Profile options on the Control Pages]]

On the positive side, changing the profile can:

The reverse of these is also true, if your line cannot support a profile selected.

==Notes==

*The fastpath (non-interleaved) profiles are more likely to drop on a noise burst than the interleaved profiles

==How long does a profile change take?==

Not long! The profile change is set through to TalkTalk Wholesale as soon as you click the button on the control page, and the line will resync within a minute. If the profile change failed, then the log will say failed, it was successful then it will say Done:

[[File:Tt-profile-changed.png]]

=Understanding the Profile Names=

[[File:Tt-profile.png|link=TalkTalk Wholesale Line Profiles List]]

*We have a table of all the available profiles, [[TalkTalk Wholesale Line Profiles List|See here]]

==Annex A Line Profiles==

*X denotes the adaptive setting:

**If this is S then the profile is dynamic

**If this F then the profile is fixed.

*YYY denotes the Interleaving settings:

**F indicates that interleaving hasn’t been applied and that this is a fast profile.

**I followed by a number indicates the size of the interleaving delay. The greater the number the greater the interleaving applied.

*SNR denotes the target Signal to Noise Margin.

**Where this is a single number, this number indicates the target for both upstream and downstream

**Where there are two, the first indicates downstream and the second indicates upstream.

**The lower the number the greater the achievable line rate, the higher the number the higher the number then the lower the achievable line rate.

**Note: Some fixed profiles omit the SNR property from their name, where this is the case their target margin is 6 dB.

==Annex M line profiles==

AnnexM profiles are available to customers with the 'Premium' option on their service.

**(S) Dynamic: This is where a maximum downstream speed is set but the line may not support that speed so the highest supportable speed is negotiated.

**(F) Static: This is where a maximum downstream speed is set and the line will be fixed at that specified speed.

*YYY denotes the Interleaving setting:

**F indicates that interleaving hasn’t been applied and that this is a fast profile.

**I followed by a number indicates the size of the interleaving delay. The greater the number the greater the interleaving applied.

*MInpN denotes the Impulse Noise Protection values. Where this is set to 0 there is in none, else the values are that for Downstream followed by upstream, H denotes 1⁄2 a tone.

==Diagnostic Profiles==

There are a few diagnostic profiles that can be used to isolate faults.

==View the Profile list==

*We have a table of all the available profiles, [[TalkTalk Wholesale Line Profiles List|See here]]

=Profile Factors=

==SNR==

SNR is a measure of signal strength and as such is measured in Decibels (dB). The values in use on the TTW network are:

*6 dB

*9 dB

*12 dB

*15 dB

==3dB==

3 dB is now supported! As of November 2015 customers can request a 3 dB profile. The process is a little long winded, but once a Support staff member picks up the task 3 dB can be applied within a few minutes. Do contact us.

==Interleaving, Error Correction and Delay==

Packets of data that are transferred across a DSL line are split into smaller blocks of data; these are then sent sequentially sent across the DSL line. As they arrive at the receiving end, they are recombined into the original larger packets of data.

If one block of a larger packet is lost due to line interference, the packet can be recreated using the remaining blocks that were received; data blocks reserve some space for data which can salvage a partially damaged block. This is known as ''error correction''. Interleaving can be used as a form more robust form of error correction.

The ‘delay’ of the interleaving is simply a measurement of the size of the interleaving buffers. The size is measured in milliseconds (ms).

The buffer sizes available on the TalkTalk network are:

*Off (fast)

*8ms

*16ms

The fastpath (non-interleaved) profiles are more likely to drop on a noise burst than the interleaved profiles

==Impulse Noise Protection==

Impulse Noise Protection (INP) is an error correction feature of ADSL2+ which makes interleaving more affective. It does

not increase delay but does add in more error correcting bits which results in a drop in line rate for less noisy lines. Because

of the increased noise immunity however, a slow noisy line will be able to sync at a higher rate with this feature enabled.

Note:

On some hardware, INP can result in a substantial drop in downstream speed and should only be used where a line is

particularly noisy and only slow speeds are achievable.

[[Category:Line Profiles]]