Hi Ana,
Very, very sorry for the late response.
Your question brings back memories of X.25. X.3, X.28, X.29, X.75, etc..
For Telecommunication Switching nodes X.25 was used to extract and send information IT systems connected
to the X.25 Packet Data Network (PDN). Generally, the file retrieval application was specific to the vendor.
The low layers, i.e. Layer 1-3, used X.25. As an example, AXE10 used IOG 3 and 11 (Input Output Group)
to store files (e.g. CDR / Toll Tickets, Statistics, etc..). The files were retrieved using MTP / X.25.
Following are CDR Collector protocols that can be used with X.25: FTAM, CMISE/CMIP, XFER, MTP, AMATPS/BX.25, EADAS, etc..
At the time of writing (2019) we now have FTP(s) using TCP/IP. The last two decades has seen the overall
migration of X.25 WANs to IP Networks.
VBR/ Wallis Dudhnath