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 co mponents such as busses ap pear in Chapter 6,
‘‘Additional Maintenance Procedures’’.
PNC Configurations
The PNC is provided in one of two different config urations: Direct Connect and
Center Stage Switch (CSS). In either configuration the TN570 Expansion
Interface (EI) board provid es the interface to the data on the TDM/PKT busses. In
the direct connec t configuration up to three PNs co nnect by hardware b etween
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 con nected. Each SN
consists of a carrier conta ining the following comp onents (in critical reliab ility
systems, each SN is duplic ated on a second , identically config ured carrier):
■1 to 16 switch node interfac e (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 nod e.
■1 or 2 switch node cloc k (SNC) circuit pack s (TN572)
The SNCs provide timing for bit sync hronized 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