Microsoft® Lync Server 2010 Unleashed

Using Network Layer Firewalls with Lync Server

Wikipedia defines a firewall as a part of a computer system or network that is designed to block unauthorized access while permitting authorized communications. It is a device or set of devices configured to permit or deny computer applications based on a set of rules and other criteria.

There are several types of firewall techniques including

• Packet filtering—Packet filtering inspects packets as they are passed through the network and rejects or accepts these packets based on defined rules. Typically, these rules are in the form of source address to destination address on port XYZ, allow. Packet-filtering firewalls are generally fast but can be difficult to configure for applications that dynamically ...