Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[olwalh]

I am looking for help in understanding what is an acceptable error level on VDSL 2 lines.

I am wondering if any kind soul would be able to point me towards some guidance on what is an acceptable error level on VDSL2 line before DLM kicks in.

I appear to have a high number of FEC errors and upstream CRC errors, however I am have some problems determining from my service provider what is acceptable, and depending on who I speak with I get very different answers.

Many Thanks

[kitz]

Its a long process and hard to explain in a few sentences because there are many different steps and no easy way of explaining it.  I'll try but theres a more in depth explanation on the main site:  DLM Process... any way here goes :-


DLM Trigger events are retrains, Errored Seconds and SES. *

The number of events to trigger action depends on which stability level your ISP uses.

    ISP's known to use NGA Speed Profile: AAISP, Plusnet, Zen.  BTr?
    ISP's known to use NGA Standard Profile: Sky, TalkTalk

Unfortunately we are unsure about BTr, as some say standard some say Speed and Ive even seen mention that BT will change it between Speed/Standard, but I think that would really depend on talking on someone who really knows what they are doing and knows how to request this from BTw... so don't hold your breath on that.


The amount of errors per day you can get away with depends upon your stability level and they are calculated as MTBE (Mean Time Between Errors)
     MTBE =  Days Uptime in seconds / Number of Err Secs.

So if you line has been up all day and you have 250 E/S thats 86400/250 = 346. 
So based on MTBE = 346

If your stability level set by your ISP was Standard that would give you an ILQ Amber. If your ISP is using Speed then your ILQ would be Green.

Another example

2160 Err Secs = MTBE of 40 (86400/2160)
MTBE 40 = Amber on Speed or Red on Standard.


Green = Good. DLM may reduce your profile
Amber = OK.  DLM takes no action
Red = Bad.  DLM will take action.


---
*Since G.INP DLM may look at something like the LEFTRS count,  but we have no conclusive proof and that's a guess on my part so do not take it as gospel.