Avaya 03-300430 User Manual

In a CSS configuration with duplicated Port Network Connectivity (PNC), EI circuit packs reside 
in the Switch Node Carrier (see 

on page 1180). 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.
A PN-to-PN connection can be extended through a DS1 converter complex. (See 

on page 1181). When discussing problems 

that may be related to fiber links, the DS1 converter is considered part of the fiber link. If 
diagnosis of the problem points to fiber connectivity and a DS1 converter circuit pack is part of 
the connectivity, problems with the DS1 converter circuit pack should be investigated (see 

on page 1077). The DS1 converter 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:

●

SNI in the CSS to which the PN’s EI connects

●

Physical 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.

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