DS0 DP Loopback eoc Remapping

Upon receipt of subsequent DS0 DP loopback codes when the D channel is disabled, the U-BR1TE III remaps the subsequent DS0 DP loopback sequences into the respective ISDN eoc loopback messages. This capability will permit all downstream ISDN D channel enabled U-BR1TEs, U-Repeaters, and TRISDN elements to respond to standard DDS DS0 DP loopback commands via the ISDN eoc as shown in Figure 7.

Test
Head
	SLC-5
U-BR1TE	T1	U-BR1TE	ISDN	IDSL
1B		1B+D	RPTR	OCU-R
DS0 DP #1		DS0 DP #2	DS0 DP #3	OCU
		Loopback	Response

Figure 7. IDSL/DDS Loopback Response

NOTE

For DDS circuits with the D channel disabled, all tandem U-BR1TE elements should be ADTRAN U-BR1TEs with DDS Loopback Capability for remote end test operation (OCU) to function properly. See 2B in Figure 6. In D channel disabled applications, older non-DDS vintage U-BRITEs may not pass the OCU latching loopback sequence to the IDSL OCU-R.

Upon receipt of an OCU latching loopback sequence the U-BR1TE III passes the OCU sequence in-band downstream to the IDSL OCU-R. U-BR1TE IIIs do not respond to the CSU latching loopback command but simultaneously passes it through to the CSU/DSU while mapping the NT1 eoc address. The IDSL OCU-R reverses sealing current on its 4-wire AMI DDS interface to place the customer CSU into loopback upon receipt of the CSU latching loopback. The following data sequence enables the DS0 DP, OCU, and CSU latching loopbacks:

1.Minimum of 35 transition in progress (TIP) bytes (X0111010).

2.Minimum of 35 loopback select code (LSC) bytes: DS0 DP (X0000101), OCU (X1010101), CSU (X0110001).

3.Minimum of 100 loopback enable (LBE) bytes (X1010110).

4.Minimum of 32 far-end voice (FEV) bytes (X1011010).

If the U-interface of the U-BR1TE III is not in sync, the unit transmits Mux-Out-of-Sync (X0011010) upstream towards the network.

X Denotes Don’t Care bit - either a 1 or a 0.

Disabling DS0 DP, OCU, or CSU latching loopback sequence:

1. Minimum sequence of 35 TIP bytes.

Front Panel Tests

The valid front panel tests in leased modes are ADR1, CRTX, LPTX, and LPBK for all circuit positions. NT1, ADR1-ADR6 loopback tests are valid for the LULT mode only. ADR2 would be used to test a U-Repeater or ADR2 and ADR3 would be used to test TRISDN elements respectively.

Initiate Loopback at IDSL OCU-R

When used for DDS, the SLC-5 U-BR1TE may initiate a loopback at the IDSL OCU-R. The in-band latching OCU loopback code is sent to loop the IDSL OCU-R when the NT1 address is selected on SW3. To invoke the OCU loopback at the IDSL OCU-R, the front panel test knob must be in the NT1 address location.

ADTRAN U-BR1TE Bidirectional Loopback

In LULT mode, the ADTRAN U-BR1TE will execute a bidirectional loopback when performing DS0 DP loopback. Refer to Figure 8 for an illustration of the bidirectional loopback.

ADTRAN U-BR1TE

IDSL OCU-R

Test Set

Bidirectional

loopback

Figure 8. ADTRAN U-BR1TE Bidirectional

Loopback

61102040L4-5B

Section 61102040L4-5, Issue 2

SLC-5 U-BR1TE III specifications

The ADTRAN SLC-5 U-BR1TE III is an advanced digital subscriber line (DSL) technology that plays a crucial role in delivering high-speed broadband services to residential and commercial customers. As part of the SLC-5 product line, this device is designed to seamlessly support both traditional TDM and next-generation packet services, ensuring versatility and strong performance in various network configurations.

One of the key features of the SLC-5 U-BR1TE III is its ability to support multiple DSL technologies, including ADSL, ADSL2+, VDSL, and VDSL2. This flexibility allows network operators to deploy the most suitable technology based on customer requirements and available infrastructure. By utilizing these DSL technologies, the device provides enhanced data rates, allowing for increased bandwidth and better overall service quality.

The SLC-5 U-BR1TE III is known for its robust architecture, which accommodates up to 48 DSL lines per unit. This high-density capability makes it an attractive option for service providers aiming to optimize their network investments. Additionally, the unit supports various interfaces for integration within existing systems, including T1/E1 and Ethernet, making it easier to connect to core networks without significant upgrades.

Another notable characteristic of the SLC-5 U-BR1TE III is its built-in intelligence, which enables dynamic bandwidth allocation. This feature optimizes how bandwidth is distributed among subscribers to ensure equitable access and smooth service delivery, even during peak usage times. Furthermore, the device supports advanced monitoring and management capabilities, helping operators maintain network performance and address issues proactively.

In terms of deployment, the SLC-5 U-BR1TE III is designed for easy installation in diverse environments, such as central offices or remote locations. Its compact form factor and fan-less design contribute to reduced power consumption and lower operating costs, making it an environmentally friendly choice.

Overall, the ADTRAN SLC-5 U-BR1TE III is an exemplary solution for service providers seeking to enhance their DSL offerings. With its support for multiple DSL technologies, high-density capabilities, dynamic bandwidth management, and ease of deployment, it continues to be a cornerstone in the evolution of broadband connectivity, paving the way for improved user experiences and increased satisfaction.