DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Maintenance Architecture
1-13Port Network Connectivity (PNC)
1
techniques for general PNC components such as busses appear in Chapter 6,
‘‘Additional Maintenance Procedures’’.
PNC Configurations
The PNC is provided in one of two different configurations: Direct Connect and
Center Stage Switch (CSS). In either configuration the TN570 Expansion
Interface (EI) board provides the interface to the data on the TDM/PKT busses. In
the direct connect configuration up to three PNs connect by hardware between
each pair of PN EIs. See
Figure 1-4
.
Figure 1-4. Direct Connect PNC
In the CSS configuration, up to 16 PNs (including the PPN) can connect to one
switch node (SN). With two SNs, up to 22 PNs can be connected. Each SN
consists of a carrier containing the following components (in critical reliability
systems, each SN is duplicated on a second, identically configured carrier):
■ 1 to 16 switch node interface (SNI) circuit packs (TN573)
Each SNI serves as the interface for TDM/PKT data to and from its
associated PN EI or to and from an SNI in the other switch node.
■ 1 or 2 switch node clock (SNC) circuit packs (TN572)
The SNCs provide timing for bit synchronized switching among the SNIs.
Slot #
Slot #
Slot # Slot #
2
2
2 1 2 1
Cabinet 2 Cabinet 3
Carrier A Carrier A
Cabinet 1
Cabinet 1
EPN
EPN
E
E
E E E E
I
Fiber Links
I
I I I I
PORT Carrier
PORT Carrier
PPN
PPN
