InDesign CS6 Socket FTP connection

I cannot publish login credentials to that server (it's client's server). I know though that those are correct - as I said I can log in with them with FileZilla but can't from InDesign. If I try connect to different server I can log both from FileZilla and scripts.

And as editor I'm using ExtendScript Toolkit.

The only difference I know between those 2 servers is that client's one got ssl installed on it.

Below is the core of the code that I'm currently using for just initial connection (without pushing files to the server):

var ftp = {

	verbose:true,
	encoding:"BINARY", // or ASCII

	log:function(message)
	{
		if(this.verbose)
		console.log(message);
	},

	error:function(message) {

		console.log("ERROR:"+message);
	},

	connect:function(host, port, user, pass) {

       
        this.channel = new Socket();     
        this.channel.encoding = "UTF-8";
  

		if (this.channel.open(host + ":" + parseInt(port)))
		{
			try {
				// get welcome message
				if (!this.response(220))
				error.log( "FTP connection refused." );

              //  console.log(this.channel.read());
              
                 this.command("USER " + user);
				if (!this.response(230, 332))
				error.log( "Server rejected username." );


				this.command("PASS " + pass);
				if (!this.response(202, 230))
				error.log("Server rejected username or password." );

			}
			catch (e) {
				this.close();

			}
			finally {
				this.log( "FTP Connected!" );
				return true;
			}
		}
		else
		{
			this.error('Internet connection?');
		}

	},

	command:function(cmdS) {
		if (cmdS)
		{
			this.log("[CMD]:"+cmdS);
			return this.channel.write(cmdS + "\r\n");
		}
		else
		{
			return this.channel.write("\r\n");
		}
	},

	response:function(expectLow, expectHigh) {
		var replyS;
		var code;

		// bypass any marks (and empty lines)
		do {
         
			replyS = this.channel.read();
            console.log(replyS);

			code = replyS.match(/^(\d{3})\s/m);
		}
		while (!code);

		this.log("[RSP]:"+replyS);

		// this should be the actual response
//		code = replyS.match(/^(\d{3})\s/m);
		if (code && code.length == 2) {

			code = parseInt(code[1]);
			if (code == expectLow || (expectHigh && code > expectLow && code <= expectHigh)) {
//				if (_FTPC_DO_LOG) logFile.writeln("--Found code: " + code);
				return replyS;
			}
		}

		return null;
	},
	close:function () {
		// send quit
		this.command("QUIT");
		this.response(221);
		// close controlChannel
		this.channel.close();
	}
}

Code above is included withing 'main' script as lib/ftp.js:

#targetengine "session";
#include "lib/ftp.js";
#include "lib/console.js";
#include "app/global_vars.js";
alert("connecting");
connection=ftp.connect(<host>, 21, <login>, <pass>);
alert("connected");

 conosle.js and global_vars.js are just for printing results in nice window.