One of the key features includes the ability to provide contemporary technology over an IP backbone, and also overcome the limitations of any PBX systems, since no PBX system offers long loop driver capabilities and that no PBX system shall be able to connect to telephone sets over such long (4-8 KM) distances.

An E1 integrated channel bank solution (with an E1 PRI (Q.931) ISDN Interface on the E1 side) provides upto 30, FXS Ports on the customers side - which shall connect to upto 30 customer's telephone sets (each connection can have as many a two / three telephone sets / extensions in parallel, depending on their distance from the E1 PRI ISDN channel bank.

Application Note:

The E1 end of the channel bank with the E1 PRI (Q.931) ISDN Interface shall connect to your Cisco AS5350 E1 Router(s) / Call Manager(s), through the E1 PRI (Q.931) ISDN Interface(s). The AS5350 E1 Router(s) / Call Manager(s), shall carry the Voice Over IP traffic and then inter-connect on your IP backbone.

On the customer side, the E1 PRI integrated channel bank solution shall provide 30, FXS interfaces (each of which shall drive upto an 800 Ohms FXS loop - which shall be 4-8 KM, depending on the cable gauge being used on the analog plant) and connect to analog telephone sets at the customer's premises.

The FXS ports shall provide the dail-tone to the customer's telephone sets and accept DTMF dialing from customer's telephone sets.

How does this work: On the CALLING SIDE, the customer pick's up the handset to make a call. The FXS port
provides the dial-tone. The customer dials the number and the call is transmitted through the E1 port of the integrated E1 PRI (Q.931) ISDN channel bank to the E1 PRI ISDN Port of the Cisco VoIP Router / Call Manager and the call is processed, accordingly.

On the RECEIVING SIDE the call, which had been processed by the Cisco VoIP Router / Call Manager is received over the IP backbone and routed to the RECEIVING SIDE. The E1 PRI ISDN Port of the Cisco VoIP Router on the the RECEIVING SIDE alerts the RECEIVING SIDE that a call is being received and the corresponding FXS port of the CALLED NUMBER provides a 75VRMS RING signal to the customer's telephone set and makes it ring. When the customer answers by picking up the handset the ring disconnects and the call is established.

Features include:

a). It is a cost-effective solution, since the Cisco equipment connects to external equipment through E1, PRI ISDN ports. The long-loop FXS drivers are an intergared part of the E1, PRI ISDN channel bank which provides the FXS ports with dial-tone and an integrated 75VRMS ring generator (required to ring a telephone set over such a long loop).

b). It is less expensive.

c). The proposed solution is a compact solution - thus less prone to faults. Modular and easy to service.

d) Using simple FXS line drivers require the duplication of the FXS circuits that already exist on the analog ports of the Cisco equipment - if that is used. This not only increases the possibility of equipment failure but also increases the size and the bulk of the equipment that shall be required to be used. This also results in higher costs shall cost more and be less efficient.

d). The E1 integrated channel bank solution offers and provides the capability to drive not just the FXS loops over a longer distance by providing the extra current and voice amplification over a longer analog spans, but integrates a HIGH CAPACITY RING GENERATOR which delivers a 75VRMS, un-balanced ring-signal which shall be required to provide a ring current and voltage to a telephone set over such a long loop.

e). Fully protected as per the ITU-T standards against external induced voltages from power cables etc. that shall be common to such long-haul FXS loops.

f). Shall connect to upto 30 customer's telephone sets (each connection can have as many a two / three telephone sets / extensions in parallel, depending on their distance from the E1 PRI ISDN channel bank.

Features of the E1, PRI (Q.931) ISDN channel bank include:

- TE / NT mode switchable
- CALLER ID display facility
- TCP/IP telnet remote access
- TEI value - user selectable

The VCL-PRI ISDN (Euro ISDN) Multiplexer bridges the gap between the analog and the digital E1 world by providing an intelligent interface to connect E1, PRI ISDN to 30 analog telephone sets. VCL-PRI ISDN (Euro ISDN ) Multiplexer is an ideal choice for Corporate and ISP customers who wish to connect their equipment with E1, PRI ISDN digital interfaces to analog telephone sets.

The VCL-PRI ISDN (Euro ISDN ) Multiplexer shall interface to the E1, PRI ISDN port of any Switch / Server / PBX using PRI ISDN (Euro ISDN) signaling as per ITU-T Rec. Q.931 to interconnect up to 30, analog interfaces to the E1, PRI ISDN port.

• VCL-PRI (Euro ISDN) Multiplexer - Product Brochure (PDF)
• VCL-PRI ISDN (Euro ISDN) Multiplexer - Technical Specifications

Application Diagram:

• E1 PRI ISDN with Cisco

• E1 PRI ISDN with Qunitum

• E1 PRI ISDN - Call Center Application