Chapter 1. Introduction

equipment. This DLCI is valid until the call is disconnected and may be assigned a different value each time a call is requested.

PRODUCT OVERVIEW

The FSU provides a low cost solution for the CPE equipment in a private or public frame relay network. The FSU connects to the frame relay network via 56/64k DDS (digital data service) or T1/FT1 access links. Connections to 56/64k DDS are made using an integral 56/64k DSU or an external DSU. T1/FT1 connections are made using an external T1 DSU/CSU through a V.35 interface.

The FSU provides connections to the user equipment through two independent ports emulating a DCE device. These ports can be configured for either RS-232 or V.35 signal specifications. Synchronous protocol speeds up to 512 kbps and asynchronous protocol speeds up to 38.4 kbps are supported.

The FSU handles each frame of the user data in a three-step manner. The first step is terminating the user protocol. The layer at which this termination occurs varies depending on the user protocol selection for a given port. The next step is examin- ing the user protocol destination address and routing to the destination port and virtual circuit. The last step involves encapsulating the information field of each frame and re- encapsulating based on the destination port configuration. A similar process is used for frame relay frames received on the network port.

The major features of the FSU are as follows:

Two DTE (data terminal equipment) ports for use on a single frame relay network interface.

Support for IP (internet protocol), SDLC (synchronous data link control), Bisync, SLIP (serial link IP), PPP (point-to-point protocol) both sync and async, frame relay, BOP (bit-oriented protocol), and async protocols.

SNMP (simple network management protocol) management capability provided inband with support for RFC 1315 (frame

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FSU User Manual

61200.130L1-1

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ADTRAN 1200130L1, 1200130L2 user manual Product Overview