allow Ip out for all protcols block Ip in for all protcols block ICMP in/out allow HTTP However trojans can find another ways to enter the system, so you must use a good internet security product with firewall.
The most common Network routing protcols used for interior routing is OSPF and RIP. RIP is still common because of its compability whit older hardware and software.
Go to this link. It discusses VoIP which is a type of telephone which doesnt charge as it uses the protcols from the internet.http://en.wikipedia.org/wiki/VoIPAnswerThere are analog and digital telephones (IP phones) used in the communication industry. To make analog phone compatible to IP service an Analog adapter in needed in order for the voice signal to run over the internet connection.
Unless we have an ageement between the two communicating parties information may get lost or miscommunicated. This agreement is the protocol. Communications protocols usually have a number of parts e.g. Handshake, encoding method, compressions methods, packet / frame structure, addressing etc. Anyone can write a protocol, but in order for it to be useful, people (systems) must use it widely. This is why protocols are often defined by standards bodies, but some protocols e.g. SSL can be used widely even though they are not specifically from a standards body. In short - if we don't have a protcols we won't be able to communicate between different devices.