13.4 PBX Configuration—[5-4] Optional Device—External Relay
PC Programming Manual References
10.7.1 PBX Configuration—[2-7-1] System—Class of Service—COS Settings—Optional Device & Other
Extensions—
External Relay Access
Feature Guide References
2.1.2.2 Internal Call Block
2.18.4 External Relay Control
PC Programming Manual
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