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Access Technical Analysis and Consulting Services - Telephony Interfaces on IADs/MTAs

Telcordia can apply its vast experience in telecommunications to test the telephony interfaces of Integrated Access Devices (IADs) and Multimedia Terminal Adapters (MTAs) to demonstrate compatibility with customer premises equipment and service feature offerings. This can also be extended to chips or OEM sub-component modules used in these products. We can test to the specifications of Telcordia Generic Requirements as well as ITU and ANSI Standards. The following provides an outline of what would be included in a typical analysis program, and how Telcordia can work with you to customize this to your product and your needs. Click here to learn about the Value Proposition afforded to IAD/MTA manufacturers by the Telcordia Access System Technical Analysis and Consulting Services.

Basic Telephony

One of the key Telcordia Generic Requirements documents that we would base an analysis on is GR-57-CORE. Although GR-57 was originally written to apply to Digital Loop Carrier (DLC) systems, selected transmission and signaling criteria from GR-57 can also be applied to IAD/ MTA products. For a basic IAD/MTA device with one or more station ports (i.e. ports that apply power and dial tone toward a telephone and recognize off-hook and DTMF address signals from the telephone), the following functional areas of GR-57 would be applied:

  • Characterization of loop current feed output.
  • Characterization of ringing output.
  • Detection of loop closure/loop open, including ring trip and flash.
  • Measurement of return loss and longitudinal balance.
  • Characterization of transmission path (e.g. loss, noise, frequency response, etc.)
  • Measurement of line-to-line interference such as cross-talk and impulse noise.

This list represents a starting point that would be reviewed and modified based on your specific product. For example, most IAD/MTA products are designed for applications on the customer’s premises with much shorter loop lengths than required for a typical DLC system (12,000 feet or more). In this case we would refer to corresponding criteria in GR-909-CORE, which was written to apply to Fiber in the Loop (FITL) systems with loop lengths up to 500 feet. Your stated loop range and ringing load capacity will be used to custom tailor a test program to your product. If your product provides additional types of telephony interfaces such as FXO or E&M, we can add those to the package based on additional sections of GR-57.

Packet Voice Architecture-Specific Tests

The transmission tests in the above list assume traditional µ255 PCM encoding (ITU G.711). If your product features additional voice compression encoding we can offer voice quality measurements to ITU Standards P.800 (PAMS), P.801 (PSQM) and P.802 (PESQ). Similarly if your product features echo cancellation we can offer testing to ITU G.168-2000.

If your product recognizes DTMF address digits, we can demonstrate that it will do so over the full range of frequency, level and tone duration deviations that customer’s equipment is allowed to present at the Network Interface. Similarly, if your product generates call progress signals such as dial tone, we can demonstrate that it does so within the limits of frequency, level and cadence deviations that a traditional PSTN switch could present over a local loop to the Network Interface. The controlling specification for this interface is ANSI Standard T1.401.

Limited environmental testing

Telcordia also offers the following optional limited environmental testing:

  • Operation at the temperature extremes, in which a Telcordia selected subset of the above tests will also be conducted at the minimum and maximum operating temperatures specified by the supplier.
  • Limited Level 1 (shall survive) and Level 2 (shall not become a fire or safety hazard) ac power fault tests per GR-1089-CORE.
  • Limited Level 1 lightning surge tests per GR-1089 (only if your product is intended to be connected to outside cable pairs).

Summary

Whether your product is a chip, OEM sub-component module, simple residential gateway or a feature rich enterprise solution incorporating additional telephony interfaces, Telcordia can work with you to develop a comprehensive analysis package customized for your product that can accelerate your time-to-market and speed market acceptance.

We can provide value earlier during your development cycle with consulting services and informal testing for your internal use. When you are ready to go to market, we can provide independent corroboration of your product’s conformance to specifications and standards through a Telcordia Distributable Analysis Report that you can choose to show to your prospective customers. After all, once you have achieved convergence of voice and data over the packet network, "you still have to ring the phone." Let us help you demonstrate that to your customers.

Please contact Scott Yeomans (+1 732-699-3443) for more information.