AT&T 555-230-894 User Manual
Overview and Roadmap
1-2
Issue 1 September 1995
Standard Reliability
DEFINITY System G3 standard reliability systems provide the most cost-
effective product. This is the only reliability offering for a G3s system. Standard
reliability systems do not duplicate Tone-Clock(s), the Control Carriers, or any
inter-Port Network (PN) connectivity.
effective product. This is the only reliability offering for a G3s system. Standard
reliability systems do not duplicate Tone-Clock(s), the Control Carriers, or any
inter-Port Network (PN) connectivity.
Standard reliability systems use the following components:
■
One control carrier per port network (Expansion Port Network (EPN) or
Processor Port Network (PPN))
Processor Port Network (PPN))
■
One Tone-Clock per port network
■
Simplex inter-Port Network (PN) connectivity (via fibre-optic cables)
High Reliability
The G3i high reliability option provides duplication of hardware associated with
the Processor Port Network (PPN) Control Carrier.
the Processor Port Network (PPN) Control Carrier.
High Reliability systems use the following components:
■
Duplicate Control Carriers in the Processor Port Network (PPN)
■
Duplicate Processor Port Network (PPN) Tone-Clocks, one in each
Control Carrier
Control Carrier
■
One Tone-Clock per Expansion Port Network (EPN)
■
Simplex inter-Port Network (PN) connectivity
Critical Reliability
G3i critical reliability option provides the highest reliability through duplication of
the control carrier(s), inter-Port Network (PN) connectivity, and Tone-Clocks.
the control carrier(s), inter-Port Network (PN) connectivity, and Tone-Clocks.
Critical Reliability systems use the following components:
■
Duplicate control carriers in the Processor Port Network (PPN) and
Expansion Port Network (EPN)
Expansion Port Network (EPN)
■
Duplicate Tone-Clocks in each port network (Processor Port Network
(PPN) and Expansion Port Network (EPN))
(PPN) and Expansion Port Network (EPN))
■
Duplicate inter-Port Network (PN) connectivity, using duplicated
Expansion Interface circuit packs and fibre optic cables.
Expansion Interface circuit packs and fibre optic cables.