Equipment Interconnection Standards ATT-TP-76450, Issue 18
AT&T Technology Operations April 2018
ATT-TP-76450
Common Systems Equipment Interconnection Standards for AT&T Technical Equipment Spaces
Presented in this document are the Common Systems Equipment Interconnection Standards for equipment placement and interconnection in the ATT Technical Spaces. Users of this document should note that requirements and information contained within may only be excerpts of full requirements necessary for an acceptable installation of network equipment in an ATT facility. Users must refer to reference document for detailed requirements.
Target Audience: The primary audience for this document is telecommunications equipment manufacturers. This document will also be used in the PDF process associated with Requests for Information (RFI), Requests for Price (RFP) and Requests for Quote (RFQ) for equipment placed into the ATT Local Exchange Companies and AT&T Corporation networks.
Effective Date: April 2018
Issue Date: April 2018
Expires On: N/A
Related Documents: See Reference Section of this document.
Canceled Documents: ATT-TP-76450, Issue 17
Issuing Department: Network Staff, IP&O Common Systems
Documents Coordinator: Brent Courtney – (678) 714-1055, E-Mail:
1 General
1.1 Requirements
This document provides the requirements for interconnection of new equipment in the AT&T Technical Spaces. The appendices include the ATT equipment evaluation process to be used to verify compliance to these requirements.
1.2 Purpose
AT&T’s networks are designed around fundamental standards for the purposes of meeting interconnection, safety, and industry standards. New equipment is required to integrate into the network seamlessly (fit, form and finish), without the impact or cost pressure to compensate for the product introduction.
The purpose of this section is to provide equipment suppliers with an overview of the AT&T network interconnection requirements most commonly encountered as non-compliant with new equipment and a process for relaying information about compliance to these requirements.
This document is not intended to be a comprehensive list of all AT&T interconnection requirements. A product's compliance with the requirements and objectives of this section will not be the sole basis for the acceptance of the product, however noncompliance with one or more of the requirements or objectives of this section may be the basis for a product's denial of purchase.
1.3 Scope
Unless otherwise stated, the requirements contained herein apply to equipment systems and assemblies intended for installation in network equipment buildings, equipment areas within buildings, electronic equipment enclosures such as controlled environmental vaults, outside electronic equipment cabinets, and customer locations.
1.4 Pre-assembled versus Field Assembled Network Equipment
Network Equipment layouts provided as overall solutions need to be reviewed in one of two ways regarding the applicability of Common Systems components and products. For the purposes of this document, AT&T Network Carriers are only concerned with the connectivity and interconnection issues between the OEM equipment and the AT&T network facilities.
OEM design practices internal to the Network Equipment hardware are not reviewed under this documentation.
OEM connectors and external contact points will meet the requirements contained in this document for performance, reliability and suitability. The use of a “Plug Play” system using internal self-contained Network Elements must also meet AT&T standards contained in ATT-TP-76200.
If the product uses various components that are interconnected together, this document will be applicable for interconnection between the various external components and cabling in addition to stand-alone Common Systems components that may have been standardized with other products within the ATT Network Carrier companies. If the OEM has presented a solution that uses “off the shelf” separate components that are externally cabled within the bay or relay rack, validation and use of the AT&T standard product lines shall be given.
Example: All DSX-1, DSX-3 and FDF panels will be provided by ADC/Commscope for the AT&T Network.
Finally, determinations will need to be made with AT&T Network Carrier company’s technical staff as to whether the items provided within the product meet either pre-assembled requirements or will be field assembled. Pre-assembled products will be considered within any Network Equipment/Element hardware box or panel that includes intelligent hardware or software. The assembly of multiple pre-assembled Network Equipment/Element products within the same footprint will be negotiated with the AT&T Network Carrier companies. The assembly of multiple pre-assembled Network Equipment/Element products outside of the same footprint will be handled as a field assembled installation. Any Network Equipment/Element that uses a passive product panel or box that does not include intelligent hardware or software will meet AT&T Network Carrier product approval standards and will be field assembled.
All assemblies, including internal wiring between components shall meet workmanship standards that include a neat and well-secured assembly with no sharp edges or cable/wire ends exposed.
1.5 ATT-TP-76450 Internet Web Site
Copies of this document and general information about AT&T’s environmental equipment standards may be found at https://ebiznet.att.com/sbcnebs/.
1.6 Product Evaluation Process
ATT-TP-76450 Product Evaluation Process is documented in Appendix A of this document. Equipment manufacturers should follow this process for each new Network Element under review by AT&T Network Carriers.
1.7 Additional AT&T Requirements
The following is for notification purposes only. Refer to the directions given to obtain further information on these subjects. Verification of conformance to these standards is not part of the evaluation process for this section.
1. ATT-TP-76200, Network Equipment and Power Grounding, Environmental, and Physical Design Requirements
- ATT-TP-76300, AT&T Installation Requirements
- ATT-TP-76400, AT&T Design Engineering Requirements
1.8 Adherence to AT&T Standard Suppliers
Within the Common Systems Checklist, standard corporate providers of the product are listed as applicable. Selections of this product are performed through AT&T Services Inc. ATO on behalf of the entire AT&T Enterprise. Each approved provider shall use AT&T approved PIDs, distributors and pricing.
1.9 Reasons for Reissue
The Reason for Reissue part of this section identifies the changes made to this document when it is revised.
Section 2.1.1 – added sections 2.1.1.1 & 2.1.1.2
Section 2.5 - changed requirement to require safety and regulatory certifications
Appendix B - updated checklist
2 DC / AC Power Interconnection Standards
2.1 General
2.1.1 Nominal -48Vdc
Nominal –48Vdc is the standard platform for power delivery to all network equipment. The design criterion of the nominal -48Vdc power is based on a normal operating voltage between -50Vdc to -56.7Vdc, with nominal rating of -48Vdc and low voltage of -40Vdc measured at the input terminals of the network equipment.
2.1.1.1 Power Supply
Power Supply Units (including rectifiers, voltage inverters, and voltage converters) shall be provided to AT&T internal to the chassis of the product. Power supplies shall not be external to the product’s chassis or “in-line” with the power wiring to the product.
2.1.1.2 Internal Power Storage Devices
Products provided to AT&T shall not contain Power Storage Devices such as Lithium Ion Batteries of any size of AH capacity. Capacitors are allowed as part of designed circuits.
2.1.2 AC Powered Equipment
Equipment shall be a minimum of ATT-TP-76200 Level 1 compliant or shall be required to be placed in a 1 Hour Fire Rated Area.
2.2 DC Power Cabling
2.2.1 Redundant Power Feeds
Redundant power feeders are required for Carrier Grade Level 3 network equipment. Each element/shelf/circuit pack, whichever is the smallest independent load device of the equipment, shall obtain power from at least two power feeds.
2.2.2 Power Feeder Information
Redundant power feeder information must be provided in the supplier's response documentation to be in compliance with this item. Power feeds (supply and return) provided by manufacturer’s shop wired configurations shall be paired and closely coupled.
2.2.3 Battery Return Conductor
Each power feeder shall have its own battery return conductor. This design concept shall also carry through directly to each piece of equipment.
2.2.4 Battery Return Configuration DC-I
Equipment battery return configuration shall be DC-I. Equipment configured with the battery return and chassis ground bonded together (DC-C) is not preferred. The DC-C configuration cannot be utilized with dual plant operation.
2.2.5 Diverse Cable Routing
Equipment shall be designed to accept diverse power cable routing with inputs on each side of the equipment.
2.2.6 List Drain Information
Battery return and current path information must be provided in the supplier's response documentation to be in compliance with this item. List 1, List 1X, List 2 and List 2X drains shall be provided in the ATT-TP-76200 ESP Form documentation.
2.2.7 Drain Definitions
Defined below are the four drain categories used in this document.
· List 1 Drain: This represents the average busy-hour current required at normal operating voltages at operating conditions as provided by the equipment manufacturer. List 1 current drains are used to size batteries and rectifiers. The cumulative List 1 current drain is the current consumed on both the A and B supplies.
· List 1X Drain: The current that will flow in one side of a dual powered circuit when the other supply circuit has failed and the power plant feeding the remaining circuit is at the normal operating voltage (float voltage).
· List 2 Drain: This represents the peak current required to operate equipment at –42.64Vdc. This value is based on manufacturer-supplied data and calculated to the AT&T minimum -42.64Vdc engineering design level and equipment configuration.
· List 2X Drain: The current that will flow in one side of a dual powered circuit if the other supply circuit is failed and the power plant feeding the remaining circuit is at 42.64Vdc, engineering design level, or the total power consumption of the network equipment in watts divided by 42.64Vdc.
2.3 Power Terminations at the Equipment
This section describes the various acceptable power connectors and connections that are approved for use within AT&T for Carrier Grade Level 3 products. See Table 2-1 for DC classification of acceptable power connections based on cable termination.
2.3.1 Rear Power Terminations
It is preferred that power terminations be located on the rear of the panel. All power connections shall be clearly labeled. DC power terminations shall be fully protected with a non-metallic, non-flammable cover.
2.3.2 Front Power Terminations
Equipment designed as “front access only” (no rear access allowed) shall have the power terminations on the front of the equipment. All power leads entering the front or side shall be protected from accidental bumps, pulls and hits. All power connections shall be clearly labeled. DC power terminations shall be fully protected with a non-metallic, non-flammable cover.
2.4 DC Connectors
Only approved connectors (lugs) shall be utilized. Approved lugs are provided by Burndy, Panduit and T&B as noted in the Minor Materials List (MML).
Connectors used to attach the product to external power cabling shall conform to the following requirements.
2.4.1 8 AWG and Larger Stranded Power Cable
Power input cable that will accept # 8 AWG or larger connector terminations shall use dual threaded post (stud) termination able to accept the appropriate two-hole crimp connection. The two-post termination may be either 1”, 3/4”, 5/8” or 1/2“ on centers. Refer to Table 2-1 for acceptable connectors.
2.4.2 16 AWG to 10 AWG Stranded Power Cable
For applications where the size of wire supplying or distributing power to/from the equipment is 16 AWG to 10 AWG stranded power cable, pressure crimped ring type connectors shall be used on the power cable. Refer to Table 2-1 for acceptable connectors.
2.4.3 Equipment Surface Terminations
Equipment surface terminations shall accept crimp connections that meet the following specifications for 16 AWG and larger stranded power cable:
· UL486A Wire Connectors and Soldering Lugs for Use with Copper
· UL467 Grounding and Bonding Equipment Conductors
· UL 486C Splicing Wire Connectors
· SAE-AS25036 (Insulated Copper Ring Crimped Terminal - Dimensions)
· SAE-AS7928 (Copper Ring Crimped Terminal - Specifications)
Equipment submitted for approval should provide a UL listed (power) termination strip designed and designated as “field wireable” to insure product compliance with the UL listing of the product. This termination or barrier strip should be able to accommodate ring lug connectors that comply with the UL, CSA and Mil Spec listings.
2.4.4 18 AWG Power Cable and Smaller
For applications where the size of wire supplying power to the equipment is 18 AWG power cable or smaller, mechanical connectors may be used. Refer to Table 2-1 for acceptable connectors.
2.4.5 Connectors and Hardware
Refer to Table 2-1 for acceptable connectors.
· The connectors shall be listed by a Nationally Recognized Test Laboratory for its intended use.
· The connector shall be tested to assure long-term tightness and reliability. The following tests are acceptable for this requirement; IEC 60068-2-6, Basic Environmental Test Procedures, Part 2: Test Fc and Guidance: Vibration (sinusoidal); EIA Specifications 364-27B (Mechanical Shock Test Procedure for Electrical Connectors), 364-28D (Vibration Test Procedure for Electrical Connectors and Sockets), Telcordia GR-63-CORE and Telcordia GR-1089- CORE. Other vibration test procedures demonstrating long-term reliability will be considered for evaluation.
· The product supplier shall provide documentation of routine maintenance (if any) associated with the supplied connector.
· Wago type pressure spring connectors, connectors that crush the wire with a screw and snap-on type power connections are not approved for use and will be denied compliance.
· Connecting hardware (bolts, nuts and washers) shall be Durium or silicon-bronze per ASTM B99. The Ny-Loc type nuts are not approved for use and will result in non-compliance.
Table 2 – 1
Acceptable termination / Associated Listings22 AWG – 18 AWG / Mechanical; American Standard UNC threads (Class 2 fit) / Listed by NRTL, IEC 60068-2-6, EIA SPEC
364-27B, 364-28D
16 AWG – 10 AWG / One or Two-hole crimp connection. American Standard UNC threads (Class 2 fit) / UL467, UL486A, UL486C, SAE-AS25036, SAE-AS7928
8 AWG – 1AWG
1/0-4/0
250MCM –750MCM / Two-hole crimp connection. American Standard UNC threads (Class 2 fit) / UL467, UL486A, UL486C, SAE-AS25036, SAE-AS7928
A “YES” for 2.4.5 indicates compliance to Table 2-1 and non-approved connectors are not being utilized.
2.5 AC Connectors
AC power connectors shall be compliant to the following certifications - FCC Part 15, UL Listed and cUL, RoHS. All AC Connectors shall be NEMA or IEC Rated and Certified.