DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Maintenance Object Repair Procedures
9-1426SNI-BD (SNI Circuit Pack)
9
SNI-BD (SNI Circuit Pack)
The TN573 Switch Node Interface (SNI)circuit pack is part of the Center Stage
Switch (CSS)configuration. It resides in a switch note carrier that alone or with
other switch nodes make up a CSS. SNIs connect to other SNIs or Expansion
Interface (EI) circuit packs via fiber links. SNI to EI fiber links are used to connect
port networks to a switch node carrier and SNI to SNI fiber links are used as
inter-switch node fibers. In critical reliability systems, the fiber link connections
are duplicated as part of Port Network Connectivity (PNC) duplication. In
standard reliability and high reliability systems, the PNC is not duplicated.
There may be up to 16 SNIs in a switch node carrier. They are located in slots 2
through 9 and slots 13 through 20. Slot 11 in a switch node carrier is not used.
One or two TN572 boards (SNCs) must reside in switch node carrier positions 10
and 12. The SNIs connect to other SNIs in the same carrier via the backplane;
these connections within the same carrier are referred to as peer-links. Each SNI
also connects via an optical fiber or metallic connection to another SNI in another
carrier or to an EI in the Processor Port Network (PPN) or in an Expansion Port
Network (EPN). These connections are referred to as fiber-links.
The Switch Node Clock (SNC) provides timing for the SNIs in the entire carrier.
When two SNCs reside in the same switch node carrier, one is in active mode
and one is in standby mode. The yellow LED on the active SNC will be on solid.
The yellow LED on the standby SNC will be off. See the SYNC section for an
explanation of how SNIs are involved in timing synchronization.
Figure 9-84
shows an unduplicated CSS with one switch node. A single switch
node can accommodate up to 16 port networks, including the PPN. A system
with two switch nodes can accommodate up to 22 port networks. Figure 9-85
shows a two-switch node CSS with duplicated PNC (four switch node carriers). In
this configuration, each PNC (A and B) contains two switch nodes. The cabinet
numbers for the switch node carriers are typical cabinet numbers. The EPNs and
PPN on the top half of the figure (PNC A) are the same as the EPNs and PPN on
the bottom half of the figure (PNC B).
MO Name As It
Appears in
Alarm Log Alarm Level
Initial System
Technician Command to
Run
1
1. UU is the universal cabinet number (1 for PPN, 2 -44 for EPNs). C is the carrier
designation (A, B, C, D, or E). SS is the number of the slot in which the circuit pack
resides (01 to 21).
Full Name of MO
SNI-BD MAJOR test board UUCSS s SNI Circuit Pack
SNI-BD MINOR test board UUCSS s SNI Circuit Pack
SNI-BD WARNING test board UUCSS s SNI Circuit Pack
