Avaya 03-300430 User Manual

!

WARNING:

If the Expansion Interface (EI) circuit pack you are troubleshooting is associated 
with a Survivable Remote EPN (SREPN), before the SREPN can be returned to 
normal service, every LAPD EI link problem must be cleared, and the SREPN 
slide switch on the TN2301 (located in the SREPN carrier) must be manually set 
to the normal position. See 

page 1183 in this section.

Refer also to Avaya MultiVantage Solutions Installation and Maintenance for Survivable Remote 
EPN, 555-233-121.
Following this introductory description of the Expansion Interface (EI) circuit pack are sections 
on the following topics:

●

●

●

●

●

●

●

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 PNs. EI 
circuit packs 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 converter complex, used to remote a PN

●

A Switch Node Interface (SNI), in a center stage switch (CSS) configuration

●

A survivable remote EPN (SREPN)

EXP-INTF

MAJ

test board location s

Expansion Interface circuit pack

EXP-INTF

MIN

test board location s

Expansion Interface circuit pack

EXP-INTF

WRN

test board location s

Expansion Interface circuit pack