Needs a ISDN switch/simulator/emulator in between according to:
nfortunately you cannot connect them in back to back because ISDN has its own protocol stack. An ISDN switch would be needed in the middle. There are some ISDN switch emulator for testing purposes.
SDN BRI requires a switching device in the circuit to work; it’s not as simple as reversing tip and ring - you could use an ISDN simulator for this purpose. ISDN back to back is possible using the following cards: VIC-2BRI-ST & VIC-2BRI-NT/TE (NOTE, these are mainly used for Voice applications & if I understand correctly this is not what you are looking for) http://www.cisco.com/en/US/tech/tk652/tk653/technologies_configuration_example09186a008010ef6c.shtml ISDN simulator is the best bet.
The following sources suggest two devices can be connected with their BRI interfaces:
Free CCNA Workbook - How to make a T1 Crossover Cable for use with WIC-1T cards.
Searching for “isdn emulator”/“isdn simulator” on ebay gives results varying from EURO 150 - 900.
GL Communications Inc. - PRI ISDN Protocol Emulator provides a commercial ISDN Emultor.
arcatech products: