By default, Windows 7 firewall blocks unrequested, unapproved incoming and outgoing traffic to reduce potential threats. At times, it may also block legitimate traffic if not properly configured and may cause applications’ problems. Connectivity issues may block applications outgoing communications when your Windows 7 machine is acting as a client or block incoming communications if your Windows 7 machine is sharing data such as, sharing folders to other clients. Other connectivity issues can happen when Windows firewall allows incoming traffic from the LAN or domain but blocks traffic from other networks.
The Windows 7 firewall controls traffic that your computer exchanges with the network or Internet and it uses rules to control this behaviour. A single firewall rule allows you to control how a specific type of network traffic behaves.
In corporate networks you can use Differentiated Services Code Point (DSCP) values to prioritize traffic for best performance of the most important traffic. However, if you manage a small network and your perimeter devices do not support DSCP, there is an alternative method known as traffic throttling which allows you to specify the amount of bandwidth a specific application can consume. Traffic throttling does not have any network infrastructure requirements.
Although, the cost of bandwidth is much cheaper now-a-days, you cannot throw more bandwidth to applications to solve network congestion problems without controlling the consumption by the various bandwidth-hungry applications! As the trend of multimedia streaming and real-time networking is increasing at an extraordinary pace, network congestion problems will occur as these applications tend to consume all available bandwidth.