Nortel Networks 6300 manual Modem Carrier Card, Firmware and Software

Chapter 1 Introduction

PRI Interface

Memory

This interface resides on the MLB in the form of a module whose RJ45 connector is accessible through the rear panel of the Remote Annex 6300. This interface is controlled by a second 486DX2 processor, whch also controls the internal modems.

The MLB has 8 megabytes of main DRAM, and an additional 4 megabytes of DRAM is used by the PRI interface controller.

Flash Memory The MLB supports 2 megabytes of Flash memory.

Modem Carrier Card

Modems

PCM Codec

The Remote Annex 6300 can be configured with 0, 4, 8, 12, 16, 24, or 32 internal V.34 modems. The modems, located on quad modem cards, are installed on the Modem Carrier Card. The modems receive data from a TTL serial channel and convert the data to a modulated analog waveform. The analog signal is then presented to a pulse-code- modulated coder/decoder (PCM codec).

The Remote Annex 6300 uses PCM codecs to convert the analog signals coming from the modems into 8-bit serial data streams. The data streams are multiplexed and passed to the PRI interface along with data that is purely digital in nature, such as that used with V.120 and synchronous PPP protocols.

Firmware and Software

Firmware	The Remote Annex 6300’s ROM contains firmware for performing
	power-up self-tests and loading operational code. A non-volatile
	EEPROM stores the configuration parameters.
	The Remote Annex 6300 can have a boot image in Flash ROM or can
	receive its image from a device on the network; this image is used to
	boot the Remote Annex 6300.

Remote Annex 6300 Hardware Installation Guide 1-3