I am unable to connect to server from outside network

Whenever I run minecraft_server.1.8.1, the server loads fine other than a list of exceptions:
[22:45:45 INFO]: Loading properties
[22:45:45 ERROR]: Exception handling console input
java.io.IOException: The handle is invalid
at java.io.FileInputStream.readBytes(Native Method) ~[?:1.8.0_40]
at java.io.FileInputStream.read(Unknown Source) ~[?:1.8.0_40]
at java.io.BufferedInputStream.read1(Unknown Source) ~[?:1.8.0_40]
at java.io.BufferedInputStream.read(Unknown Source) ~[?:1.8.0_40]
at sun.nio.cs.StreamDecoder.readBytes(Unknown Source) ~[?:1.8.0_40]
at sun.nio.cs.StreamDecoder.implRead(Unknown Source) ~[?:1.8.0_40]
at sun.nio.cs.StreamDecoder.read(Unknown Source) ~[?:1.8.0_40]
at java.io.InputStreamReader.read(Unknown Source) ~[?:1.8.0_40]
at java.io.BufferedReader.fill(Unknown Source) ~[?:1.8.0_40]
at java.io.BufferedReader.readLine(Unknown Source) ~[?:1.8.0_40]
at java.io.BufferedReader.readLine(Unknown Source) ~[?:1.8.0_40]
at pr.run(SourceFile:81) [minecraft_server.1.8.1.jar:?]

Despite these exceptions, when I log onto the server from the same computer or another connected to the same network as the server, it works fine. However, when I try from an outside network, it's unable to connect and says "java.net.ConnectException: Connection refused: no further information:"