Connecting IP phones to PBX ipLDK-300 without SIP?

Question

Asterisk

Available: Mini PBX ipLDK-300, VIP-board for this PBX, Elastix virtual machine, ISDN PRI \ E1 from a telephone operator with 8 time slots and a bunch of external numbers, an internal telephone network for +|- 100 numbers
Task: Organize a gradual transition to IP -telephony.
Question: Is it possible to transfer control to an Elastix virtual PBX without connecting a SIP provider, but using ISDN PRI \ E1 from a telephone operator (Operator --> Modem --> Mini PBX ipLDK-300)?

Answer 1

It can be done. The issue of funding. If there are no problems with this, I would recommend buying a Digium TE235BF board to make the "operator (E1) > asterisk (E1) > LDK (E1)" scheme, then you can gradually migrate to astric (I did this 3 times with Panasonics (3 pieces) and meridians)
Option more budget buy something like Eltex SMG-2

Answer 2

Option 1
1. Set up a SIP trunk towards Asterisk (Elastix)
2. Set up routing in LDK-300
Option 2
1. Buy an E1 board and connect the stream to Asterisk
2. You still need to connect LDK and Aster at least via SIP