EXP-INTF (Expansion Interface Circuit Pack)
Issue 1 May 2002
8-763
555-233-143
The TN570 or the TN776 Expansion Interface (EI) circuit pack provides a TDM-
and packet bus-to-fiber interface for the communication of signaling information,
circuit-switched connections, and packet-switched connections between
endpoints residing in separate port networks. EI circuit packs reside in the Port
Networks (PNs) and are connected via optical fiber links. An EI can be connected
to:
■
Another EI — in a direct-connect configuration
■
A DS1 converter in a DS1 CONV complex — used to remote an PN
■
A Switch Node Interface (SNI) — in a center stage switch (CSS)
configuration
■
A survivable remote EPN (SREPN)
In a CSS configuration with duplicated Port Network Connectivity (PNC), the
PPN’s EI circuit packs reside in the Switch Node Carrier (see
). In this case, the EI and SNI circuit packs may be connected via a metallic
cable instead of an optical fiber link. Metallic cable should be tested and replaced
in the same manner as optical fiber.
An PN-to-PN connection can be extended through a DS1 CONV complex. (See
). When discussing problems that may be related to
fiber links, the DS1 CONV is considered part of the fiber link. If diagnosis of the
problem points to fiber connectivity and a DS1 CONV circuit pack is part of the
connectivity, problems with the DS1 CONV circuit pack should be investigated
(see
). The DS1 CONV circuit pack enters into
diagnostics for the EI circuit pack via such tests as the Neighbor Query test
(#237), the Fiber Out-of-Frame test (#238), the Two-Way Transmission test
(#241), and the Packet Transmission test (#589).
In a critical-reliability system, the fiber link’s are duplicated as part of PNC
duplication. In a high-reliability system with a CSS (Center Stage Switch) and
unduplicated PNC, a single point of failure between the media server and the CSS
is eliminated by duplicating each link, consisting of:
■
EI in the PN
■
SNI in the CSS to which the PN’s EI connects
■
Physical metallic or fiber paths between them
These dual connections normally share the call-processing load. Should one of
these links fail, the entire load can be shifted to the operational link.
shows the location of the EI circuit packs in a typical
unduplicated PNC, direct connect configuration.
Summary of Contents for S8700 Series
Page 50: ...Maintenance Architecture 555 233 143 1 26 Issue 1 May 2002 ...
Page 74: ...Initialization and Recovery 555 233 143 3 12 Issue 1 May 2002 ...
Page 186: ...Alarms Errors and Troubleshooting 555 233 143 4 112 Issue 1 May 2002 ...
Page 232: ...Additional Maintenance Procedures 555 233 143 5 46 Issue 1 May 2002 ...
Page 635: ...status psa Issue 1 May 2002 7 379 555 233 143 status psa See status tti on page 7 406 ...
Page 722: ...Maintenance Commands 555 233 143 7 466 Issue 1 May 2002 ...
