ISDN PRI Errors – Is it the PBX or the carrier?

Only by producing hard written data can you determine where the error lies. If your PBX vendor and your carrier can not agree, have both parties produce the data below.

From the PBX vendor

This is a screen shot from VENDOR diagnostic equipment showing errors on an ISDN PRI “toward the network”. That means it was the carrier’s fault, not the PBX. The errors were so severe as to cause hang-ups. We provide our customers with solid proof of the source of the error before we “finger point” toward the carrier.


From the carrier

This output is from a carrier’s smart jack showing errors on the carrier circuit. It’s likely a copper issue