After ADBF board extension, the customer will start acceptance test. The test server will send two CPE test to NCP via TL1 interface. One test will be done at DSLAM port status "activating", another test will be done at DSLAM port status "deactivated".
The failure with port 0/6/52 of site obur-007a appears at status "deactivated". The CPE test with fastcheck option reports failure. Further check in NCP log shows there is "training" information after SLTS sent the "handshaking" to the port.
SLTS recognize the port as activated when it received "training" when the fastcheck option is set to "true".
From test logic this port is thought to be failure as SLTS got port activated when the port on DSLAM was set to "deactivated".
After redo the cabling on the SID panel the failure with port 51 and 52 were gone. There is no interference any more.
Firstly the status of the failure port 0/6/52 was checked on board level. When the port was set to "deactivated" on DSLAM level, this port was in the same status as other faultless ports.
The port 0/6/52 and the ports nearby (0/6/51 and 0/6/53) were set to status "deactivated". The check with SLTS on port 0/6/52 with fastcheck showed correct result. There was no "training" information anymore.
When the port 0/6/51 was set to "activating" and the test was done again, the failure reappeared. When the port 53 was set to "activating" and the test was done again, the failure didn't reappear. It is obvious that the port 51 was affecting the port 52 and sent out the "training" information.
Port 0/6/51 and 0/6/52 were tested to check the cabling quality. The result showed both ports have relative high attenuation.
The test with modem verified the conclusion of SLTS test. The line quality of port 0/6/51 and 52 were not good.
According to the analysis onsite, we suggest to check the cabling, SID panel and subscriber cable at first when a deactivated port cannot pass fastcheck CPE test.