web services - Oracle Database URL_HTTP Issue -

i'm trying invoke web service send encoded (base64 encoding) file name. shorter file name works fine, when file name increases after encoding pl/sql fails invoke web service , turns out bad request 400 error. based on our observation far have seen upto 65 chars worked once sent ~ 89 chars failed.

*code snippet

  req := utl_http.begin_request(url, 'put',' http/1.1');   utl_http.set_body_charset('utf-8');   utl_http.set_header(req, 'username', username);   utl_http.set_header(req, 'password', password);   utl_http.set_header(req, 'content-type', 'application/octet-stream');   utl_http.set_header(req, 'content-length', '32767');   utl_http.set_header(req, 'accept-encoding', 'gzip');   utl_http.set_header(req, 'transfer-encoding', 'chunked');    filename := utl_raw.cast_to_varchar2 (utl_encode.base64_encode (utl_raw.cast_to_raw (ffile.file_name))); //encoding file name before sending   utl_http.set_header(req1, 'x-filename', filename); //causing problem if length increases*