When the U-BR1TE III operation is normal, the ADR7 position of SW1 does not have a function.
NOTE
This test option is only available on power up of the U-BR1TE III.
ISDN Only - MLT Channel Test -LUNT Mode
When a Pair Gain Test Controller (PGTC) is connected to the U-BR1TE III and the Test Initiate Voltage (116 Vdc behind 8 kΩ) is applied to the Tip with the Ring open, the following occurs:
1.The channel unit sends a Channel Test mp-eocmessage downstream to the LULT.
2.The unit produces a 333 Hz test tone between the Tip and Ring leads. This tone is compliant with TR-TSY-00465.
When the Test Initiate Voltage is removed, the test tone is subsequently removed, the active test status indication to the bank controller is removed, and the Return to Normal mp-eocmessage is sent to the LULT. The channel unit then begins re- synchronization of the U-interface between the LUNT and the ISDN switch.
ISDN Only - MLT Channel Test -LULT Mode
When a PGTC initiates a channel test at the COT, the COT channel unit sends a Channel Test mp-eoctoward the LULT. Upon receipt by the LULT of this mp-eocmessage, the following events occur:
1.The channel unit informs the bank controller of a test request.
2.Upon completion of handshaking with the channel test equipment, the bank controller commands the channel unit to close its channel test relay. This has the effect of connecting the customer drop to the common equipment through LPTT and LPTR and the channel unit U-interface to CHTT and CHTR. The test setup sequence is complete.
3.Upon completion of the automatic test, the channel unit is commanded by the bank controller to de-energize the channel test relay.
4.Upon reception of the Return to Normal mp-eocmessage, the channel unit begins re-synchronization
of the U-interface between the LULT and the NT1.
Performance Monitoring TR829
The U-BR1TE III supports performance monitoring remotely from the ISDN switch.
IDSL/DDS Description
The U-BR1TE III may be deployed in the adjacent to customer mode to provide transport for DDS/Frame Relay services with an ADTRAN IDSL OCU-R. This allows pair savings over traditional DDS deployment on local loops up to 18 kft on mixed gauge wire. The IDSL OCU-R is used to terminate the U-interface at the customer premises provided by the U-BR1TE III and to convert the 2-wire ISDN signal to a 4-wire AMI DDS signal for presentation to the customer. Together, the U-BR1TE III and IDSL OCU-R allow testing over the ISDN transport network to be performed with traditional DDS methods. In this mode U-BR1TE IIIs may be placed in tandem and function as DS0 DPs while the IDSL OCU-R functions as an OCU. See Figure 6 for various U-BR1TE III DDS arrangements.
DDS Testing
For leased mode or DDS applications with the U-BR1TE III the D channel is typically disabled. Without the D channel, standard ISDN eoc loopbacks are unavailable to the ISDN transport system and testing may only be accomplished by using the in- band DDS loopback commands. The U-BR1TE III responds to latching loopback sequences for the DS0 DP. The U-BR1TE III allows the OCU loopback command to pass inband downstream to the IDSL OCU-R.
Upon receipt of a DS0 DP latching loopback sequence the U-BR1TE III initiates a bilateral loopback for the B1 channel. This bilateral loopback allows testing of the 2B1Q local loop to the IDSL OCU-R simultaneously with network testing to the U-BR1TE III.
