Kitz Forum
Broadband Related => Broadband Technology => Topic started by: renluop on July 16, 2013, 11:52:14 AM
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Telnet on my 582N has this line "INP [DMT symbols] Downstream 1.3 Upstream 2.0. What do those values do?
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INP is Impulsive Noise Protection. It's a Broadcom feature to improve the resilience of a connection under impulse noise conditions.
DSLstats should copy these figures to the main Stats page, but at present this doesn't happen with Technicolor routers.
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Hi! I'd sussed what the INP meant. ;D, so was more interested in the values and their interpretation.
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I was wrong to say that it's a Broadcom feature, but Broadcom have improved on it.
I'm not really competent to go into detail, but broadly speaking it's a compromise between speed and resilience. Without the Broadcom extensions at the exchange end, higher values result in lower connection speeds, and values over 2 can render the connection incapable of syncing. Values less that 1 are more normal.
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INP is a symbol, if INP is set it's normally set at 3. You have 3 (If set at 3 INP) symbols to protect against high amount of errors this is due to noise on the line. The more symbols the more errors/noise that there is on your line and to deal with this it has to allocate a high INP value. On a normal Interleaved line you're looking at 3 or 3.25 INP value.
Worth noting this also relation to other values to your line such as block sizes for your line, etc.
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INP is a symbol, if INP is set it's normally set at 3. You have 3 (If set at 3 INP) symbols to protect against high amount of errors this is due to noise on the line. The more symbols the more errors/noise that there is on your line and to deal with this it has to allocate a high INP value. On a normal Interleaved line you're looking at 3 or 3.25 INP value.
Worth noting this also relation to other values to your line such as block sizes for your line, etc.
So my interleaved line does not conform to the normal values, you quote. hmmm.
I can see nothing about blocks in telnet, but this is the current info in the section dealing with INP
Number of bearers: 1
Bearer 0 DS US
INP [DMT symbols]: 1.22 2.00
Delay [ms]: 7.99 8.00
Depth []: 64 0.00
R: 10 0
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The INP can be any value but normally the value is 3 from experince.
They aren't actually called blocks, they're your R Value etc but I cannot remember which off the top of my head.
R: 12 16
They aren't directly related, you should be looking at INP + delay. The block sizes aka I, R and N values are also part of INP (sort of), I'm sure some will disagree.