Lucent Technologies 555-661-150 manual Series Configuration Four Systems

MERLIN LEGEND Communications System Release 6.1	Issue 1
Network Reference 555-661-150	August 1998
1 Introduction
Tandem Trunking and Tandem Switching	Page 1-13

NOTE:

In the following example, the PRI tandem trunks are implemented on T1 circuits provisioned for bipolar 8 zero substitution (B8ZS) line code.

P S T N

P R I / 2 4						P R I / 2 4					B R I ( 1 6
		P R I	/ 2 4 P R I / 2				4T i e	/ 4
M L		A			M L	M BL	C	M L			D
N Y				I L		C A	T i e	/		C	A
										4
4 8 l i n e s 7 2 l i n e s4 8 l i n e s								3 2 l i n e s
								O u t s i d e
I n t e r s y s tIenmt e r s y sItnetme r s y s t e m
a n d		o u t s iadn ed			o u t s1 i2d8e- k b p s			1	2	8 - k b p s u p
								2	B	B d a t a
u p	t o 1 2 8u-pk btpo s 1 2d8a-tkab;p os u t s i d e
2 B	d a t a 2 B			d a t a u p t o 1 2 8V					-MkSb p s

C e n t r a l i2zBe dd aVtMa S / A A

Figure 1–4. Series Configuration: Four Systems

From a planning perspective, consider the following points about the series configuration illustrated in Figure 1–4.

■System D is linked to the private network by tie lines (a total of 8), so users at MLX display telephones on System D cannot see the name and/or number of a caller who reaches them from another system in the private network.

■To ensure proper transmission quality, the path of a private network call should include no more than two spans of analog tie trunks. The private network in Figure 1–4 includes one such span, between Systems C and D.

■When an outside dial-plan routed PRI call with ANI arrives on System A or B, ANI calling party information travels to a destination extension on systems connected by PRI tandem trunks (A, B, or C) but not across tie tandem trunks (System D). System D users can receive this information only from their PRI to the PSTN.

■System D is located in close geographic proximity to System C. This allows System D to use the PSTN for 2B video calls with System C at up to 128 kbps without incurring high toll costs. However, because of the tie connections, intersystem video and intersystem high-speed data calls are not supported to and from System D.