AT&T 7400 series, 7500 series, 7100 series, 2500 series manual Extension Number Portability Clusters

5-8ELECTRONIC TANDEM NETWORK (ETN) THROUGH THE ETN AND PNA PACKAGES

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In some cases, the software and/or administration used to implement the above types of networks reside on the same switch as do the ETN (Standard Network) package or the Private Network Access package. This is true of extension number portability, release link trunk networks, and distributed communications system software and/or administration. In other cases, like Software-Defined Network and main-satellite/tributary networks, the ETN tandem is totally independent of the other network and accesses it through tie trunks.

Extension Number Portability Clusters

Extension number portability (ENP) clusters are groups of System 85 (R2V3 or R2V4) and Generic 2 communications systems, on which ETN software is specially administered for node number routing among them (see figure 5-4).With ENP, users can easily move from node to node within the cluster and still retain the same extension number. It is common for ENP clusters to use 5-digit dialing, with the first digit indicating the node and the final 4 digits representing the true extension number; or to assign all ENP nodes the same set of RNXs. These dialing schemes are not mandatory, however. In an ENP cluster, it is only necessary that each extension be identified on every switch.

HOME RNXS = 220, 221, 230, 231			REMOTE RNXS = 320, 420	HOME RNX = 420
				REMOTE RNXS = 220, 221,
REMOTE RNXS = 320, 420			HOME RNXS = 220, 221, 230, 231	230, 231, 320
	SYSTEM 85		SYSTEM 85	GATEWAY SWITCH
R2V3, R2V4,			R2V3, R2V4,	TO ETN,
OR DEFINITY G2			OR DEFINITY G2	SYSTEM 85
	(NODE 1)		(NODE 2)
GATEWAY SWITCH		SYSTEM 85
TO ETN,		R2V3, R2V4,
DEFINITY G2		OR DEFINITY G2
		(NODE 3)
HOME RNX = 320	HOME RNXS = 220, 221, 230, 231
REMOTE RNXS = 220, 221,	REMOTE RNXS = 320, 420
230, 231, 420

Figure 5-4.Extension Number Portability Cluster Using Common RNXs