:toast:
Hello Gents.
Quick technicalnote. The Telco must remain compliant with ANSI standard T1.403 that stipulates that the network shall not place any DC voltages on the CPE side of the network interface. T1 NIU's (Smartjack) deployed since the mid 1990's no loger had the capability to support span thru powering. I worked on the Tansmission Engineering Staff at Verizon NY, and as a technical and operational member of the T1 NIU & HDSL RFP cross funtional teams, I added the ANSI requirement to remove span thru powering voltages to cross over the network interface (NI) AKS: Demarc.
Removal of span powering voltage to power customer CSU's was also mandated in the legacy FCC interconnection rules found in FCC part 68. The FCC Part 68 requirement went into effect in December 18th, 1989. ANSI T1.403 included the FCC requirement.
Regarding to the logging of incoming BPV's (CV-L), that is an indication of a physical problem at the CSU end of the DS1 circuit, and limited to the metallic T1 portion of the circuit between a LEC local MUX/ or SDL RT unit, assuming such a design, and the customer NI.
I find it interesting that no CRC-6 errors were reported by the CSU. A mis-optione MUX low speed card AMI, where it should be B8ZS, will not produce BPV's, but should register Excessive Zeros if such a PM register exists.
In all Westell T1 NIU's, and Pairgain 2W HDSL equipment, there is an option I specified to show B8ZS seconds. This is a 15 minute bucket that will indicate the presence of B8ZS from both the CPE & Network directions. It is intended to help diagnose a B8ZS/AMI line code misoption.
If there is access to the NIU or the HDSL Remote unit, a F-M DB9 cable connected to a PC serial port, withthe PC running a VT100 terminal emulation application (Procom/Hyperterm), will provide some additional clues as to where any errors may exist.
Second, insure that with a ISDN-PRI, the local PBX is taking timing from the service provider (XO), and is not in Master/Internal/Free Run clock mode.
Regards,
Field Ops
32 years & out
