You can search through a variety of external resources in Alma. The Library of Congress or LOC is one of the more popular external resources to use when looking for records for use in technical services. 
Alma uses the Z39.50 configuration to access these records & resources. 
If the connection terminates or unexpectedly goes down you can run into a screen like this 
Image description. A screenshot of a error screen in Alma from the MDEditor w/ text that says
An error has occurred, please try again later and contact the system administrator. Z39.50 gate error: Connection refused by the Z39.50 target.
This connection is maintained by the LOC. They will restore access eventually but we do not have any contact or way to alert the Library or Congress that access is not working