transport

This sounds like a very basic question, but I need a confirmation Does WebRTC use TCP or UDP as its peer-to-peer transport? How do I know ? I read that there are reliability mode and DTLS agreement, how does they affect? Is this transport the same for both Media and DataChannel? How do I switch between TCP and UDP? I ask this because I know that browsers have a limit on the number of parallel connections (I think they talk about TCP), and maybe UDP connection is not limited. It can use either. By default, preference is given to UDP, but depending on the firewall(s) in between the peers

I am trying to send an email with an attachment file in Java. When I send the email without an attachment I receive the email, but when I add the attachment I don't receive anything and I don't get any error messages. This is the code I am using: public void send () throws AddressException, MessagingException{ //system properties Properties props = new Properties(); props.put("mail.smtp.localhost", "localhost"); props.put("mail.smtp.host",Configurations.getInstance().email_serverIp); /* * create some properties and get the default Session */ session = Session.getDefaultInstance(props, null); /