The common-network interface ring (CNI ring) provides common-channel signaling (CCS) functionality on several Alcatel-Lucent SS7 products. It was introduced by Western Electric in the early 1980s but is still used today in all 1AESS and 4ESS,US Patent 5592466 – Network interconnect backup offices, and most of the wireline 5ESS offices.

It was designed and manufactured at the combined Bell Labs–WECo location in Columbus, Ohio.

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