DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126
Issue 4
June 1999
Maintenance Object Repair Procedures
9-787EXP-INTF (Expansion Interface Circuit Pack)
9
In a system that is configured with PNC duplication active, taking an EI out of
service that is on the active PNC will, if all other things on the active and standby
PNC are equal (i.e. both PNCs are equally healthy, the standby PNC is not busied
out, the PNC is not locked by software), result in a PNC interchange.
Survivable Remote EPN
The Survivable Remote EPN (SREPN) feature allows a DEFINITY R6r EPN (either
MCC or SCC) to provide service to the customer when:
■ The fiber (or T1/E1 Expansion Interface link to the main R6r processor)
fails or is severed
■ The R6r processor or center stage fails.
NOTE:
This feature is viewed as a “disaster recovery operation” capability rather
than as an additional reliability option.
The SREPN requires remote EPN cabinet to provide processor (SPE) capabilities
to the EPN in the event of a failure. A logic switch circuit pack (TN2301) located
in the SRPPN detects when the link to the R6r is down and switches to a link from
the local SRPPN (TN790-based processor). When the links to the R6r are
restored and verified to be stable, the logic switch is
manually reset
, and the
EPN is reconnected to the links from the R6r.
NOTE:
The SREPN feature is not available when an ATM-PNC/EI circuit pack is
used to replace the TN570 EI circuit pack in a direct-connect configuration,
or an ATM Switch is providing the Center Stage (PNC) connectivity.
NOTE:
If you suspect a problem with the TN790B-based R6si SRPPN use the R6si
maintenance documentation supplied with the SREPN feature to resolve
any alarms/errors associated with the SRPPN carrier.
SREPN Feature Active
!
WARNING:
All calls within the SREPN are terminated when the SREPN feature is
activated, and the
R6si
SRPPN takes control of the SREPN.
The SREPN feature is activated when the maintenance circuit pack (TN775C or
later and located in the SREPN) detects a problem with the SREPN’s EI (TN570B)
LAPD link to its counterpart in the R6r PPN. The TN775C maintenance circuit
pack notifies the co-located SRPPN of the problem, and the TN2301 SRSwitch
circuit pack in the SRPPN carrier switches the EI LAPD link connection from the
