Can grounding issue cause T1/E1 bounce?

[hxmengmetro]

Hi All,

We have one site which has 2Mbps E1 through ISP. Recently, it's keeping bouncing. Sometimes it was stable for couple of hours and suddenly into a intermittent status. Called ISP and they said it's grounding issue causing that. We asked electrician to check the grounding. He didn't see anything wrong. E1 is terminated with one box at the site. Looks like a modem (Maybe SHDSL modem). It has a phone line coming in. Could the phone line get disturbed by something and cause the E1 bouncing? I know for ADSL and VDSL, sometimes the EMI or other interference can affect the line SNR. Could it be the same case for SHDSL. I couldn't recall it now.

If you had this issue before, could you help share your solution and finding? Thanks a lot!

Lou

[vmiller]

What does the router show on the interface connected to the DSU/CSU ?

You can always replace the RJ-48 cable and see if the problem persists.

Is the power to the CSU/DSU correctly grounded ?

[hxmengmetro]

We found out the SHDSL modem is not grounded. That modem is like DMARC which should be always grounded. I think that's the problem. Requesting ISP to correct it. But weird thing is like you asked about show interface. The E1 controller doesn't have too many error seconds. That is confusing me.

[vmiller]

I wonder if they showed up as frame/crc's ? (not unheard of)

Glad it was a type 1 (easy to find & easy to fix)