Metrodata Limited

The APX UNI interface modules enable connection to ATM services, either as network or switch ports, or are used as trunk ports for non-ATM applications. Each UNI modules provide a single ATM interface port, with the range being standards compliant and covering all standard Telecom data rates.

The APX ASI UNI module offers an ASI serial port supporting native ATM cells, which can operate asymmetrically at up to 155Mbps. This module allows the AP to connect with other ATM equipment via an ASI circuit line (e.g. a satellite link, or a broadcast video link). This module offers an ASI interface which can connect directly to an ASI satellite modem, thereby offering a flexible bandwidth ATM over serial service (e.g. ATM over satellite).

Each UNI module performs physical layer and ATM layer functions including framing, alarm processing and cell delineation. Flexible clocking options remove network synchronisation problems. Status LED's are provided to indicate that real traffic is passing across the ATM interface.

Management and configuration of this module is achieved via the simple menu driven user interface. Extensive statistics and status information are gathered at all layers and are available to the user interface as a diagnostic aid. OAM alarm and loopback functions are supported as per UNI 3.1

Additionally SNMP Traps may be generated to indicate Link Up/Down. These modules can be "Hot Swapped" to ease maintenance, with replacement modules recovering immediately without further configuration.

This module has the following features:

• standards compliant ASI interface with dual 75 ohm BNC connectors
• operates asymmetrically at up to 155Mbps in each direction
  
• can be used in any AP chassis
• hot swap interface module, with configuration automatically loaded onto the replacement module

Applications supported:

• ATM over satellite (including asymmetric services)
  
• ATM over serial (including encrypted links)
  

The ASI UNI Module offers Satellite Operators and Service Providers a simple solution for flexible service delivery. With Satellite bandwidth being extremely valuable, efficiency is paramount. For internet backbone service delivery asymmetric operation is a general requirement and this can only be practically delivered using a HSSI interface on a Router. HSSI has two basic problems, firstly it is limited to a maximum of 52Mbps and secondly, and more practically, to very short cable runs. The ASI UNI Module offers a solution, maintaining all the benefits of HSSI whilst overcoming the shortcomings.

The ASI UNI Module provides an industry standard ASI interface for connection to the Satellite Modem. The ASI Module provides a fully configurable (1Kbps to 155Mbps) ASI data interface. Please note that the ASI UNI module will not work properly when connected to satellite modems which require MPEG structured data streams (i.e. supporting specific sized frames), instead this module requires an unstructured ASI data path.