AT&T DS1/DMi/ISDN-PRI manual Transmit Receive Direction, A L

										THE DIGITAL LOSS PLAN					4-5
			TABLE 4-2.Digital Loss Plan (Port-to-Port Losses)
		Transmit						Receive		Direction
		Direction							(Values in dB Loss)
					ONS-	OPS-	ANAL	COMB	Analog		E I A	I S L	ATO	DTO	ISL
					Line	Line	Tie	or	CO	Trunk	DCO	D T T	TRK	TRK	DCO
							TRK	DTT	BAL	N BAL	TRK
	On-premises station (ONS)				6	3	3	3	0	0	3	3	6	3	3
	Off-premises station (OPS)				3	0	2	0	0	0	0	2	3	0	0
	Analog tie trunk (A/TT)				3	2	0	- 3	0	2	2	0	0	-3	2
	Combination or digital tie trunk (D/TT)				9	6	3	0	3	6	6	6	3	0	3
Analog CO trunk (A/CO)				B A L	0	0	0	- 3	0	0	0	0	2	0	0
				N B A L	0	0	2	0	0	2	2	2	2	0	2
	EIA digital CO trunk (D/CO 0/6 loss)				3	0	2	0	0	2	0	0	3	0	0
	ISL digital tie trunk (S/DTT)				3	2	0	0	0	2	0	0	3	0	0
	analog toll office trunk (A/TO)				6	3	0	- 3	2	2	3	3	0	-3	3
	digital toll office trunk (D/TO)				9	6	3	0	6	6	6	6	3	0	6
	ISL digital CO trunk (D/CO -3/3 LOSS)				3	0	2	- 3	0	2	0	0	3	0	0
NOTE: A terminal balanced trunk is defined as meeting an ERL of ≥ 18 dB
and an SRL of ≥ 10 dB, when measured into a quiet termination at the CO.
		ANALOG									ANALOG
		FACILITY				DS1/DMI					FACILITY
		ANALOG		D4		DIGITAL			D4			ANALOG
		SWITCH		CHANNEL		SWITCH			CHANNEL			SWITCH
				BANK					B A N K
		ONS												ONS
		ONS						ONS
		NOTE: A combination tie trunk consists of a digital trunk terminating at a channel bank.

Figure 4-1.End-to-End Loss Configuration Using Combination Tie Trunks

●Port-to-port losses in Generic 1 and Generic 2 conform to the ANSI digital loss plan standard. Table 4-2, Digital Loss Plan (Port-to-Port Losses), is an excerpt from this standard. If other vendors’ switches are used in the same network, port-to-port loss measurements through such a