NEC ND-71762(E) system manual Quasi-Associated Mode, Ccis Network Redundancy

GENERAL INFORMATION FOR CCIS

4.3.2Quasi-Associated Mode

In Figure 2-10 below, nodes A and B, and A and C are connected in the Associated Mode. Nodes B and C are con- nected in the Quasi-Associated Mode.

In this configuration, signaling data between nodes B and C is routed via node A, while the communication channels are established directly between nodes B and C. This type of network reduces the hardware necessary to establish the signaling links.

Figure 2-10 Quasi-Associated Mode Network

NODE

A

NODE	NODE
B	C

Communication Channel

Common Signaling Channel

4.4 CCIS Network Redundancy

To provide maximum network reliability, two levels of redundancy are provided for the signaling links.

(1)Signaling Channel Redundancy

Redundancy of the inter-node signaling links is provided directly between the nodes by adding one more link than is necessary for the signaling traffic. This is the N+1 method. If one link fails, signaling is automatically routed via an alternate link.

(2)Alternate Signaling Path Redundancy

An alternate method of providing network signaling redundancy is to configure the network so that an alternate path is provided between the nodes.

In the network shown in Figure 2-9, if the signaling link(s) directly connecting nodes B and C should fail, the signaling would automatically be reconnected via node A without loss of service. (Node A would be designated as the Signaling Transfer Point [STP]).

ND-71762 (E)CHAPTER 2

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