Nortel Networks 553-3001-211 manual Overview, Card interfaces

NT5D33 and NT5D34 Lineside E1 Interface cards Page 245 of 894

Overview

The LEI card is an IPE line card that provides a cost-effective, all-digital connection between E1 compatible terminal equipment (such as voice mail systems, voice response units, trading turrets, etc.) and the system. In this application, the terminal equipment can be assured access to analog (500/ 2500-type) telephone line functionality such as hook flash, SPRE codes and ringback tones. The LEI supports line supervision features such as loop and ground start protocols. It can also be used in an off-premise arrangement where analog (500/2500-type) telephones are extended over twisted-pair or coaxial E1 with the use of channel bank equipment.

The LEI offers significant improvement over the previous alternatives. For example, if a digital “trunk-side” connection were used, such as with the DTI/ PRI interface card, “lineside” functionality would not be supported. Previously, the only way to achieve lineside functionality was to use analog ports and channel bank equipment. With the LEI, a direct connection is provided to the IPE. No channel bank equipment is required, resulting in a more robust and reliable connection.

When used for connecting to third-party applications equipment, the LEI offers a number of benefits. It is a more cost-effective alternative for connection because it eliminates the need for expensive channel bank equipment. The LEI card supports powerful E1 monitoring, and diagnostic capability. Overall costs for customer applications may also be reduced because the E1-compatible IPE is often more attractively priced than the analog-port alternatives.

The LEI is compatible with all IPE-based systems and with standard public or private CEPT-type carrier facilities. It supports CRC-4- or FAS only framing formats as well as AMI or HDB3 coding. Because it uses standard PCM in standard E1 timeslots, existing E1 test equipment remains compatible for diagnostic and fault isolation purposes. A/B Bit signaling may be customized according to the user’s system, including the Australian P2 signaling scheme.

Card interfaces

The LEI passes voice and signaling data over DS-30X loops through the DS-30X Interface circuits and maintenance data over the card LAN link.

Circuit Card Description and Installation