Although radio frequency is a rate of oscillation, the term radio frequency or its abbreviation RF are used as a synonym for radio â i.e., to describe the use of wireless communication, as opposed to communication via electric wires.Examples include:1  Radio-frequency identification.owever, since the antenna will pick up thousands of radio signals at a time, a radio tuner is necessary to tune into a particular frequency (or frequency range). This is typically done via a resonator â in its simplest form, a circuit with a capacitor and an inductor form a tuned circuit.
Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (email) transmission. First defined by RFC 821 in 1982, it was last updated in 2008 with the Extended SMTP additions by RFC 5321 âwhich is the protocol in widespread use today. SMTP by default uses TCP port 25.The protocol for mail submission is the same, but uses port 587.SMTP connections secured by SSL, known as SMTPS, default to port 465 (nonstandard, but sometimes used for legacy reasons).mail is submitted by a mail client (MUA, mail user agent) to a mail server (MSA, mail submission agent) using SMTP on TCP port 587. Most mailbox providers still allow submission on traditional port 25. From there, the MSA delivers the mail to its mail transfer agent (MTA, mail transfer agent).
means that port 80 is listening to all interfaces (not used) not exactly-the service World Wide Web Publishing Service was listening at this port. Once you manually stop it, you might free that port (at least in windows 7) â despot Jan 28 '13 at 12:45.one of these worked for me. I had to go to a superuser question: http://superuser.com/questions/352017/pid4-using-port-80. If it is a System ProcessâPID 4âyou need to disable the HTTP.sys driver which is started on demand by another service, such as Windows Remote Management or Print Spooler on Windows 7 or 2008.