User Guide 13510Traffic ManagementThe Firebox® X Edge e-Series supplies many different ways to manage the traffic on your network. Youcan limit the rate of traffic sent to the external or IPSec interface using QoS (Quality of Service) throughTraffic Control. You can manage data transmission by giving more or less bandwidth to different traffictypes. You can also change the visible network address of incoming or outgoing traffic to prevent con-flicts using NAT (Network Address Translation).About Network TrafficBandwidth is the quantity of data that can be sent through the network in a specified increment oftime. It is usually expressed in bits per second (bps), kilobits per second (Kbps), or megabits per second(Mbps). A T1 line supplies approximately 1.5 Mbps, while a dial-up connection supplies approximately56 Kbps. Latency is the quantity of time necessary for a packet to go from a source to a destination.Together, latency and bandwidth define the speed and capacity of a network. You can improve latencyby configuring Traffic Control. You must upgrade your Internet connection with your ISP to improvebandwidth.When too many users or devices try to send data at the same time, the Firebox® X Edge cannot send allof the data quickly. When the Edge has more traffic than the external connection can send at the sametime, some programs appear to operate slowly.Causes for slow network trafficMany programs use as much bandwidth as possible to operate. If too many users operate these pro-grams, other users cannot use the network. Peer-to-peer (P2P) services, instant messaging, and filedownloads are programs that frequently use large quantities of bandwidth.To limit the quantity of bandwidth those software applications can use, you must use Traffic Control.To deny or allow traffic from those software applications, you must configure a policy. For more infor-mation on policies, see Chapter 7, “Firewall Policies,” on page 91.
