NEC 2000 IPS manual Digital and Analog Ccis, Digital Ccis

Chapter 14 Common Channel Inter-Office Signaling (CCIS)

Digital and Analog CCIS

The PBX can provide No. 7 CCIS via either a digital network or an analog network. Regardless of the relevant network being a digital network or an analog network, CCH (Common Channel Handler) to control the common signaling channel is required.

Digital CCIS

Digital CCIS uses standard 24 channel digital T1 facilities to provide 23 B (voice/data) channels and 1 D (signaling) channel for the first CCIS dedicated T1 span. Additional T1 spans can be added and all 24 channels of each additional T1 span could be used for voice and/or data transmission. In this case, the D channel of the first T1 span is using non-facilitated associated signaling for the additional T1 spans. A second D channel of the first T1 span can be configured to provide a redundant signaling link between nodes to increase network reliability. To provide even more reliability, one channel of a second T1 span can be programmed to serve as the redundant signaling link. In this configuration, network reliability is at a maximum because if the first T1 span fails, the 23 B channels and the redundant D channel of the second T1 span would keep the network operational.

The D channel can be programmed to transmit the signaling information at rates of 48K, 56K, or 64K bits per second. At these high transmission rates, one D channel can easily handle the signaling requirements for multiple T1 spans (non-facilitated associated signaling).

When using a Satellite system as the transmission medium, the NEAX Family of systems are usually configured for digital CCIS, however, it should be noted that many Satellite systems can be configured to accept multiple analog tie lines which would be compatible with analog CCIS.

Analog CCIS

For applications requiring analog tie lines, CCIS requires the use of modems at each end of the dedicated signaling tie line. These modems can operate as high as 56K baud rate. The voice and data lines (B channels) also use standard analog tie lines. If the customer requires 7 voice / data channels between nodes, 8 tie lines are ordered providing one extra tie line to be dedicated as the signaling channel. This may appear to require more tie lines then a non-CCIS network but actually less tie lines are required when CCIS is used thanks to the intelligent Look Ahead Routing feature.

Page 14-4	UNIVERGE NEAX 2000 IPS Request For Proposal (RFP) Reference Guide
	Issue 6