3Com S26x, S27x, S24x installation manual E1 Dual Port Digital PBX Interface Card, Introduction

Hardware Components

E1 Dual Port Digital PBX Interface Card

Introduction	The E1 dual port digital PBX interface card supports digital voice communications,
	providing integrated network access (see Figure 1-12). The E1 interface card is
	installed primarily in Europe and South America. A 2-megabyte E1 card is required
	for passing data traffic and voice traffic.
Description
	Each E1 dual port digital PBX interface card uses an Industry Standard Architecture
	(ISA) bus interface and a Multi-Vendor Integration Protocol (MVIP) bus interface.
	The MVIP bus interface provides a multiplexed digital access within the PathBuilder
	S24x, 26x, and 27x switch chassis.
	The E1 dual port digital PBX interface card has two E1 ports (CAS signaling only),
	handles E1 lines with or without CRC4, and supports 120Ω and 75Ω (with the
	addition of an optional cable). The interface type is 8-pin modular.
Function
	E1 dual port digital PBX interface cards provide the digital interfaces for
	connections to a PBX. The dual port digital PBX interface cards bring PCM voice
	and channel signaling into the node. The PCM voice data and voice signaling is
	routed to a DSPM/SM card over the MVIP bus for compression and transmission to
	the motherboard.
Slot Restriction
	The E1 dual port digital PBX interface card can only occupy slot 8 in the PathBuilder
	S24x, 26x, and 27x switch chassis.

1-20 About the PathBuilder S24x, 26x, and 27x switch