Only 1.4db attenuation for upstream?
Sure, no problem. Upstream SNR 23.4 should be fine since the attenuation is quite low. If your attenuation is more than 10, then better don't change. Luckily it is only 1.4db. Must be new copper wire........

But seriously......you better hope the technician at your local DSLAM exchange know how to change it.

Changing "interleave" to "fastpath" can only be done on TM side, not user side.
No need to ask TM technician to come over. (TM charges RM50+ for each visit, in my case though, TM technicians came over and I explained to them about dsl interleaving,fastpath, and depth value plus how those things have impact on latency, when fastpath or interleave should be used and how it can be only changed by TM since TM doesn't expose such setting to user unlike Australia Telstra ISP. I showed them Australia Telstra website too. I don't get charged for the visit.   They said they will refer to their senior and voila, mine got changed to fastpath the next day  )

I got mine changed back to public IP.
Oh ya, livechat agent also requested ping plotter result from me.
I simply provided her/him with the result and clarify that the ping can be lowered further if adsl noise profile is set to fastpath.  I also wrote the interleave depth is adding 25ms plus 5ms extra ping time. So, from the pingplotter result, there is total 30ms extra latency which is caused by dsl interleaving which is simply unacceptable for online gaming. I provided them the source for the info http://www.kitz.co.uk/adsl/interleaving.htm and http://www.juniper.net/techpubs/software/c...e-config31.html , at the bottom graph, had* the livechat agent took a look at 'burst protection' latency values because TM dsl line has it activated. In worst case scenario, interleaving can increase latency up to 47ms for depth value of 64 with INP value of 2.

You can check my interleaved dsl stats screenshot where my INP were 2.64 and 2.63 for downstream and upstream. In fastpath, INP is disabled.

EDIT: Some stuff for reading....how INP and interleave depth affect each other......fair use.....two pages only. Sourced from google book?

How to know / check whether my profile is interleaved or fastpath?

Congratulation! 

I am using cheap D-Link modem which does not show the profile in DSL status, any other way to find out?

Nope, TM ancient DLINK 2640B doesn't show it.

How did you changed Interleaved to FastPath tho? Mine is like this.

Please report back if you ever get it changed back to public IP. (Which is very unlikely now)
I got few colleagues whose streamyx got assigned with private IPV4 address and they were told to use IPV6 by TM.
Probably TM changed the port too while reconfiguring it to FastPath?

What kind of sorcery is that? How do u change ur profile?