Connecting to a private FTP server behind a firewall

I have an FTP server set up in my room (student halls). I can't reach to the halls network from the outside so I need to VPN into the university network. And the firewall allows only several ports from the university network to the halls network, 21 is one of them. I'm using FileZilla and here is the output (replaced private information with *) :

Status:      Resolving address of server
Status:      Connecting to *.*.*.*:21...
Status:      Connection established, waiting for welcome message...
Response:      220-Cerberus FTP Server Personal Edition
Response:      220-UNREGISTERED
Response:      220-Welcome to Cerberus FTP Server
Response:      220 Created by Grant Averett
Command:      USER **********
Response:      331 User **********, password please
Command:      PASS **********
Response:      230 Password Ok, User logged in
Command:      SYST
Response:      215 UNIX Type: L8
Command:      FEAT
Response:      211- Additional features supported include:
Response:       MDTM
Response:       SIZE
Response:       REST STREAM
Response:       AUTH TLS
Response:       AUTH SSL
Response:       PBSZ
Response:       PROT
Response:       LANG EN*
Response:       SITE CHMOD
Response:       SITE PSWD
Response:      211 End
Status:      Connected
Status:      Retrieving directory listing...
Command:      PWD
Response:      257 "/" is the current directory
Command:      TYPE I
Response:      200 Type Binary
Command:      PASV
Response:      227 Entering Passive Mode (*,*,*,*,4,8)
Command:      LIST
Error:      Connection timed out
Error:      Failed to retrieve directory listing

Does anybody have an idea what's going wrong?