CHAPTER 1 GENERAL INFORMATION
System Outline
NEAX2000 IVS2 ISDN System Manual
ND-70919 (E), Issue 1.0 Page 7
Figure 1-3 Example of ISDN-VPN (2 of 2)

When an opposite office cannot interface with the ISDN network

PBX
B
Tie Line
PBX
A
Calling Party
Dial 1234
Called Party
ISDN
0345678910 (Office No.)
1234 (Called Party Subaddress)
C
Station No. 1234
(034567-8910)
1234