152-402-145-02, Issue 2Loopback Operation

Table 10. Summary of HiGain HDSL2 Loopback Codes and Activation Methods

 

 

 

Method of Activation

Loopback

Code

Description

Test Set

Craft Port

H2TU-C

MODE/SEL

 

 

 

 

 

 

 

 

 

 

 

NLOC

1111000

DSX-1 signal is looped back to the network at the H2TU-C.

X

X

X

 

4-in-7

 

 

 

 

 

 

 

 

 

 

 

 

NREM

1110000

DSX-1 signal is looped back to the network at the H2TU-R.

X

X

X

 

3-in-7

 

 

 

 

 

 

 

 

 

 

 

 

CLOC

1111100

DS1 signal from the customer is looped back to the

X

X

X

 

5-in-7

customer at the H2TU-R.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CREM

1111110

DS1 signal from the customer is looped back to the

X

X

X

 

6-in-7

customer at the H2TU-C.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COLB

 

Dual loopback at H2TU-C. DSX-1 signal is looped back to

 

X

X

 

 

the network at the H2TU-C and DS1 signal from the

 

 

 

customer is looped back to the customer at the H2TU-C.

 

 

 

 

 

 

 

 

 

RULB

 

Dual loopback at H2TU-R. DSX-1 signal is looped back to

 

 

X (a)

 

 

the network at the H2TU-R and DS1 signal from the

 

X

 

 

customer is looped back to the customer at the H2TU-R.

 

 

 

 

 

 

 

 

 

SMJK LpUp

11000

SmartJack Loopup or NID payload (PL) code. Invokes

X

 

 

(PL)

2-in-5

H2TU-R loopback towards network.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SMJK LpUp

1111-1111-

SmartJack Loopup or NID (ESF-DL) code. Invokes

X

 

 

(ESF-DL)

0100-1000

H2TU-R loopback towards network.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SMJK LpDn

11100

SmartJack Loopdown or NID payload (PL) code. Removes

X

 

 

(PL)

3-in-5

SMJK, NLOC, NREM, CLOC, CREM, CRGx, and NRGx.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SMJK LpDn

1111-1111-

SmartJack Loopdown or NID (ESF-DL) code. Removes

X

 

 

(ESF-DL)

0010-0100

SMJK, NLOC, NREM, CLOC, CREM, CRGx, and NRGx.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(a) The RULB dual loopback (same as NREM-CLOC) can be activated by pressing the LBK button on the H2TU-R front panel.

HiGain HDSL2 systems feature the SmartJack (SMJK) option which can emulate a Network Interface Device (NID) for the purpose of loopback testing of the HiGain HDSL2 circuit. SMJK and NREM loopbacks perform the same functions, but their initiation differs. SMJK indicates that the loopback was initiated by the 2-in-5 inband command. NREM, on the other hand, is initiated by the 3-in-7 inband command, by the H2TU-R front panel LBK button, by a command issued from the maintenance terminal, or by the H2TU-C front panel MODE and SEL buttons.

Use the inband commands to enable or disable the SMJK loopback options. The HiGain HDSL2 system setting is normally enabled to recognize all inband SMJK loopback commands.

H2TU-R-402

June 16, 2000

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