ADSL Max Training Period

[#Chri5#]

This is the first ADSL Max connection I've had setup, so I'm not familar with how the training process works.

I've found my sync rate can vary between 4.4Mbps and just under 6Mbps. However, on some sync's basic web surfing can be one legged pace (or just not work at all).

For instance, I've just rebooted my SpeedTouch 546 and these are the stats:

Uptime: 0 days, 0:07:16
Modulation: G.992.1 Annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 4,480
Data Transferred (Sent/Received) [KB/MB]: 307.00 / 1.62
Output Power (Up/Down) [dBm]: 11.5 / 17.5
Line Attenuation (Up/Down) [dB]: 26.5 / 44.0
SN Margin (Up/Down) [dB]: 17.0 / 6.5
Vendor ID (Local/Remote): TMMB / P
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 379 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 17,299
HEC Errors (Up/Down): 0 / 10,065

How do the line stats look? I suspect the previous owner of the house bodged the two extra phone extensions in (given his obvious lack of skill for DIY I've found exhibited elsewhere). I've got microfilters on all three extensions. I could get one of our comm's monkeys from work to come and improve the wiring.

I can guess the number of CRC errors is bad but what's an HEC error? Is it typical to get errors or should the counts remain low?

 

[tolien]

I've found my sync rate can vary between 4.4Mbps and just under 6Mbps.

Not unexpected. SNR margin varies.

However, on some sync's basic web surfing can be one legged pace (or just not work at all).

Packet loss due to errors normally. Not surprising given your error rate.

Uptime: 0 days, 0:07:16
Error Seconds (Local/Remote): 379 / 0

379s = 6 minutes 19s, ie 87% of the time from the modem synching up to those stats being generated, there was some transmission error.

How do the line stats look?

Bad. At that rate, I'd expect interleaving to be enabled, or your modem to lose synch.

I could get one of our comm's monkeys from work to come and improve the wiring.

More trivial step: disconnect all the extensions, and connect your modem to the master socket (ideally the test socket within), and see what you get.
If the error rate drops and/or the sync rate increases, you've got an internal wiring issue.

I can guess the number of CRC errors is bad but what's an HEC error?

Another wikipedia job:
http://en.wikipedia.org/wiki/Header_Error_Correction

Is it typical to get errors or should the counts remain low?

To a limited extent, both, with the addition of the word "relatively". Really need a "frames transferred" count to pass comment on the CRC/HEC error count, beyond that it's bad.

 

[slipd]

Bad. At that rate, I'd expect interleaving to be enabled, or your modem to lose synch.

Is interleaving enabled by 'default' by BT/ISP, or do they only start it when you get problems with your line? How can you find out if you have interleaving enabled on your line?

I've just been upgraded to MAX, but also do a lot of online gaming, so the last thing I want is interleaving turned on

SW.

 

[Burbleflop]

Is interleaving enabled by 'default' by BT/ISP, or do they only start it when you get problems with your line? How can you find out if you have interleaving enabled on your line?

I've just been upgraded to MAX, but also do a lot of online gaming, so the last thing I want is interleaving turned on

SW.

By default, interleaving will be set to auto so if your line arses about then it'll get automatically switched on. How you tell if you have it enabled or not, depends on your equipment - in my router I just saw the sync rate move from the 'Fast' column to the 'Interleave' column.

Online gaming hasn't been affected for me in the slighest since it has been enabled on my line. Pings to my favourite Q4 server are now in the 30's rather than the 20's.

 

[#Chri5#]

Not unexpected. SNR margin varies.

More trivial step: disconnect all the extensions, and connect your modem to the master socket (ideally the test socket within), and see what you get.
If the error rate drops and/or the sync rate increases, you've got an internal wiring issue.

Thanks tolien.

I suspect it's the internal wiring. The other night I noticed that the BT line comes in from a pole to a small DP high-up on the house wall. It seems at least one of the extensions has been run from that, rather than wired back from the master socket. Will investigate further.