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Standard User Bapteeed
(regular) Thu 26-Mar-15 01:45:21
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Strange speed loss


[link to this post]
 
Ive had 80/20 FTTC for over 2 years with BT always had max speed (sync) but recently its dropped abit which is fine but surely the maximum data rate would be lower instead of higher ?

Before :
6. Data rate: 19999 / 79995
7. Maximum data rate: 32440 / 94831

Now:
6. Data rate: 19997 / 75682
7. Maximum data rate: 36030 / 97587

Doesn't make much sense to me or am i missing something ?
Administrator MrSaffron
(staff) Thu 26-Mar-15 09:31:14
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Re: Strange speed loss


[re: Bapteeed] [link to this post]
 
Attenuation probably suggests that max data rate is what is possible, but noise or cross talk issues are impacting and thus reducing the actual data rate possible.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User Realalemadrid
(newbie) Thu 26-Mar-15 10:20:16
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Re: Strange speed loss


[re: Bapteeed] [link to this post]
 
Just ignore the max data rate, it is a theoretical number that cannot be achieved in practice and there is a known quirk of the HG612 FTCC modem and possibly others that when interleaving reduces the actual data rate the displayed max rate increases.

Edited by Realalemadrid (Thu 26-Mar-15 10:21:47)


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Standard User timl
(committed) Thu 26-Mar-15 14:56:20
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Re: Strange speed loss


[re: Realalemadrid] [link to this post]
 
I don't know about the attainable rate being unachievable but it certainly should be ignored.

My line demonstrates that quite well.

Max: Upstream rate = 24876 Kbps, Downstream rate = 67476 Kbps
Bearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 67951 Kbps

Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 6.1 9.2
Attn(dB): 12.7 0.0
Pwr(dBm): 13.5 1.3


Plusnet unlimited FTTC
BT Infinity 2
Standard User Realalemadrid
(learned) Thu 26-Mar-15 19:01:59
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Re: Strange speed loss


[re: timl] [link to this post]
 
Yes, there are line conditions where the reported max rate is lower than the actual, but in the OP's case where there is a high sync speed and the max data rate is above 80Mbps it is certainly not achievable!

Edited by Realalemadrid (Thu 26-Mar-15 19:03:00)

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