Asterisk as E1 switch?

Hi,

my question about asterisk is:

Can I use asterisk as a transparent switch?

E.g. I have a custom non-asterisk IVR-System with one E1. Then I plug this IVR-E1 into
an Asterisk-Server’s E1 and the Asterisk-Server itself has another E1
for outgoing calls.

IVR_E1 -> ASTERISK_IN_E1 -> ASTERISK_OUT_E1 -> PUBLIC_TELCO_SWITCH

Does asterisk’s switching occur on those low layers so that the IVR_E1 will receive the
ISDN PROGRESS / PROCEEDING / CAUSE_CODES / etc. as if it was connected directly to the
PUBLIC_TELCO_SWITCH or are these details removed by asterisk and asterisk just switches voice
channels but not the ISDN D-channel-data?

Thank you!

Silke