PairGain PG-Flex FLC-704, Manual

363-704-104-01, Revision 01

Product Overview

FLC-704 List 4

June 22, 1998

 5

Subscriber Receives Incoming Call. 

The following occurs for an incoming call (see 

Table 4

 for circuit 

interactions):

•

FLC-704 detects a ringing signal from the CO

•

FLC-704 signals the FRC-754 which then connects ringing to the subscriber

•

subscriber line goes off-hook and the FRC-754, through the FLC-704, provides an off-hook condition to the 
CO switch

Busy Condition. 

Loop start busy condition at the RT is a Ring lead negative and a Tip lead positive with loop 

current flowing. The same conditions occurs at the CO (see 

Table 5

 for circuit interactions).

Table 3.

Circuit Interactions When a Subscriber Initiates an Outgoing Call (Loop Start)

Operation

CO Switch

FLC-704 List 4 COCU

FRL-754 List 4 RTCU

Subscriber

CO Idle

No ringing

⇒

No ringing

⇒

Subscriber goes 
off-hook

⇐

Off-hook

⇐

Off-hook

CO returns dialtone

Dialtone

⇒

Dialtone

⇒

Subscriber Dials

⇐

DP or DTMF

⇐

DP or DTMF

Table 4.

Circuit Interactions When a Subscriber Receives an Incoming Call (Loop Start)

Operation

CO Switch

FLC-704 List 4 COCU

FRL-754 List 4 RTCU

Subscriber

Subscriber Idle

⇐

On-hook

⇐

On-hook

CO generates ringing

Ringing

⇒

Ringing

⇒

Subscriber goes 
off-hook

⇐

Off-hook

⇐

Off-hook

Ring trip

No ringing

⇒

No ringing

⇒

Table 5.

Circuit Interactions for a Busy Condition (Loop Start)

Operation

CO Switch

FLC-704 List 4 COCU

FRL-754 List 4 RTCU

Subscriber

Circuit busy

No ringing

⇒

No ringing

⇒

⇐

Off-hook

⇐

Off-hook