How much minimum Optical Module Input Power(dBm) is good for stable connection?

[Dravin]

My Airtel Xstream Fiber connection's Optical Module Input Power(dBm) has significantly decreased from -24 dBm to -27 dBm. Is it okay or is there a need for concern that some problem with speed and latency will be faced soon?

 

[Chip]

It should be less than -27 dBm at all times otherwise you will have intermittent issues.

 

[Firephoenix]

I have -27.88 dBm and I face constant disconnection issues, have raised complaint multiple times, local team gives the power of -18 dBm for 5 mins, closes the complaint and then again power drops to -27.88 dBm, for me it is an LCO connection so Airtel denies any help in this regards.

 

[Lolita_Magnum]

Upto -25 dBm is good and you won't experience any issues beyond that that's a hit or miss area.
Try to see if there are any fiber bends or fiber that might have been curved a bit too much.
Also check your optical temperature if it's too high, that will also increase dBm.
Issues will be immediate, so test around a bit to see if you are experiencing any slowdowns.

 

[divykhanna]

Is this good? @Lolita_Magnum

 

[Dravin]

@Chip @Lolita_Magnum @Firephoenix I made a complaint, and the service engineer visited and told me that there is nothing to worry about till -30 dBm. I tried to convenience him but he denies the fact that after -27 dBm the service degrades. 😐

 

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[Chip]

@Dravin see the 2nd last value, the lower threshold, it's -29.2 dBm so that's probably why he said so. In my Nokia ONT it is - 27 dBm whereas previously it showed -25. May have been due to the firmware that they pushed out recently to my ONT. But rule of the thumb is it should be <-25 for best performance. My line shows -20.71 now.

 

[phoenix10386]

@Chip My Nokia ONT shows the same tolerances as DivyKhanna's ONT. I once saw someplace in my Airtel Thanks app about a firmware upgrade available or required, but there was no way for me to do it.

Now, I got my ONT successfully bridged by the backend team, so PPPoE is being handled by my router now instead of the ONT. Will my ONT's firmware get updated still in this case? Any idea?

 

[Chip]

@phoenix10386 yes it will update the firmware automatically. It is pushed by the Airtel backend servers. Remember it will work only if you haven't removed the WAN setting in the ONT which uses TR-069 for pushed configuration and firmware updates. Again, if your internet is stable don't worry too much about the rx/tx optical power values.

 

[phoenix10386]

@Chip, thank you. I was mildly annoyed because my Rx value was reduced yesterday after another Airtel connection was installed in the society for someone and somehow my line was off for 2 hours.

Few days ago, after a session with Airtel NOC person to get IPv6 and Bridge Mode enabled, I discovered my Rx value to be -14.xx dB which I know was about -23.xx prior to it when the connection was activated.

That -14 became -24.xx after the line disruption yesterday. That had me annoyed and concerned.

I also wondered if somehow that Bridge Mode would interfere with automatic firmware updates at Airtel’s end.

 

[Chip]

I also wondered if somehow that Bridge Mode would interfere with automatic firmware updates at Airtel’s end.

Airtel's bridge mode is enabled on a separate LAN port of the ONT. So you get 2 connections actually..one the default PPPoE connection with Internet and TR-069 plus the one on your personal router. They don't affect your optical power ratings.

 

[imdarkray]

Still working well

 

[Dravin]

@imdarkray working but that's totally Bhagwan Bharose 😅

 

[Firephoenix]

After 3 months of struggle and raising new complaints every day these guys closed my previous complaints, I have got my power increased to -17.5 dBm, and since last 2 days I haven't faced any disruptions so I feel power was the issue.

Even got my ONT changed to the ZTE one, hopefully now I can live in peace until/unless there is again a major fiber cut and these guys again mess up the power.

 

[tatyasky]

-15 to -25 is the ideal range. Anything below -25 can cause instability.