M and MSM Series

3CRWDR101A-75 and loss of sync

Occasional Contributor

3CRWDR101A-75 and loss of sync


i've got a 3CRWDR101A-75 wlan router which worked really well for more than a year.

But some days ago troubles begun: i've got a lot of loss of sync which lasted EXACTLY 5 minutes and 30 seconds (i read it from router's log).

Then i call my ISP tech center, who said that troubles are not theirs, but mine. They say that my modem is faulty, and the line is ok. (in fact i can see really good params on the status page).

The disconnections are really random: sometimes once every 20 minutes, sometimes it happens in a couple of hours.

Now i'm testing the line with another router to try to understand something.

I've latest version of firmware (1.12 august 2009). the router passes all selftests.

The loss of connection is "brutal": i see no slowness before it hangs. it just does at once.

What can i do ? Could the router be really broken ? Lan and WLan connection are OK.

The router has been up for more than a year (which means: yes 24/7 up).

My ISP, if it could help, is Telecom Italia, with 20Mbit/s connection (ADSL 2+) with PPPoE.


Thanks in advice,



Regular Advisor

Re: 3CRWDR101A-75 and loss of sync

Sounds like your ISP has made modifications to their DSLAMs (exchanges)

Loosing Sync is a Line Problem, Noise or attenuation problems will cause this, also check your ADSL filter.

When you talk to your ISP, ask them to do a line QUALITY check and not a continuity check... Getting a reply to their pings does not mean that the line is in good shape.

If this fails you will need to raise a ticket for support, and be ready to provide ISP hardware detaisl that 3Com will need to resolve SYNC problems.

If your other router works, have it's make, model and software version available when you open a ticket.

The Tech Man Has Spoken....
The Tech Man Has Spoken....
Occasional Contributor

Re: 3CRWDR101A-75 and loss of sync

Hi Techno,

thanks for your answer. In the while i've done some inspection: My girlfriend has the same router of mine, and i asked her to swap our device for a while.

She has no problem with my router and i still have disconnection with hers!

So i do totally agree with you about the ISP faulty.

The trouble now is: how to tell them it's not me ? My ISP technician are REALLY INCOMPETENT. They just check the SNR and Attenuation.. They do not neither check pinging: just continuity!

I've raised 3 tickets about this and they still say it's me.

I think i'll call a lawer if they don't fix this.