DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Hardware Configurations
2-3Carriers in Multi-Carrier Cabinets
2
If the system has a Center Stage Switch, the E position holds a Switch Node
Carrier. In a CSS system with duplicated PNC, the D p osition holds a Switch
Node Carrier that duplic ates the one in E position. In large systems req uiring a
CSS with two Switch Nodes, the second SN is located in an EPN cabinet, for both
simplex and dup licated systems. Systems that have add ed a CSS configuration
after the original installation may have their first SN in an EPN cabinet.

Expansion Port Network Cabinets

When used for an EPN, the multicarrier cabinet sup ports one Port Network with a
daisy-chained TDM/LAN bus, or , optionally, two separate PNs if the cabinet does
not contain a Switch Node. A c abinet with two PNs has two separate TDM/LAN
bus daisy-chains. One TDM/LAN b us between carriers in p ositions A, B and C
supports the first PN, and another TDM/LAN b us between positions D and E
supports the second PN. Figure 2-1 shows locations of carriers in EPN cab inets.
Each EPN cabinet contains one Expansion Control Carrier (J58890A F) located in
the A position. In cabinets with one PN, up to four Port Carriers are added as
needed in the sequenc e B-C-D-E, unless the D or E positions are used for a
Switch Node. Cabinets with two PNs use optional Port Carriers i n the B position,
and then the C position for the first PN (above the fans). The sec ond PN, (below
the fans), is configured with the first Port Carrier in the E p osition and an optional
second Port Carrier in D position.
In large systems with a CSS that requires two Switch Nodes, the second SN is
located in an EPN cabinet (this is usually cabinet number 2, PN numbe r 2). This
EPN may not be remoted by a DS1CONV complex. An EPN with an SN has a
Switch Node Carrier in E position. In systems with d uplicated PNC, (Critical
Reliability option), the D position hold s another Switch Node Carrier that
duplicates the one in E pos ition.
Carriers in Multi-Carrier Cabinets

PPN Control Carrier (J58890AP)

The PPN Control Carrier contains dedicated slots used for circuit packs that
compose the switch p rocessing element (SPE). It does not contain p ort circuit
pack slots. This carrier always resid es in position A of the PPN cabinet. In a
system with a duplicate d SPE, a second PPN Control Carrier resides in the B
position of the PPN cabinet.