FAQ Test services

Independently of the language used to program your EPP client you need to be careful on what exactly you are reading and how you are doing so.

DNS-LU transport: Some have been using line-based techniques to read responses from EPP server, this works as expected on epp-test but fails on production server. If you read carefully the technical you will see that the end tag is '</epp>', without ANY whitespace (so no line-feed, no carriage return, no space, no tab).

On the test server you will see a line-feed following this closing tag, formatting of the XML tree adding this line-feed. On production system XML formatting is disabled so that '>' is the last character sent for an answer until the next answer is sent.

RFC3734: For this transport protocol each EPP message is prefixed with a 4 byte (network order, big endian) header which indicates the total size of the EPP message, including the header itself. This makes block-based reading pretty easy as only two block reads need to be issued per message, one for the header and on for the rest. (Don't forget that network delays may cause your read() function to return less bytes as requested, thus requiring multiple reads)

Note: For both transports you might want to strip whitespace at beginning and end of each message before handing the message over to your XML parser (RFC3734 transport should never put leading whitespace in front on <?xml header).

XML versus String: EPP is based on XML messages as is SOAP. As such it's a bad idea to assemble EPP message by doing concatenation of string segments as you may end up concatenating badly escaped sequences or even mixing charsets in a single EPP command. Decoding an EPP answer by doing pattern-matching is even more problematic as whitespace and comments may disturb your parser.

Remember that the layout of XML may change without prior warning as long as the meaning of the XML remains the same (e.g. order of elements can change as long as permitted by the schemas, comments and whitespace can also be added/removed).