Bandwidth management can be applied whether you're using failover or load balancing. Bandwidth management guarantees and/or limits bandwidth utilized by users, schedule, hosts, network location or addresses, QoS codes or network applications. Bandwidth management is also where you can create traffic priority settings. Let's look at three examples.
Example 1: Let's say I want to control the amount of bandwidth used for web browsing, which is HTTP traffic. In the configuration below for the ZyWALL 110, I've created a bandwidth policy to guarantee a minimum of 1000 kbps and a maximum of 5000 kbps for inbound HTTP traffic; plus a minimum of 256 kbps and a maximum of 2000 kbps for outbound HTTP traffic. This means I'm guaranteeing web browsing traffic will get at least 1 Mbps, but not more than 5 Mbps of download bandwidth and at least .25, but not more then 2 Mbps of upload bandwidth.
Bandwidth Guarantee - ZyWALL 110
Example 2: Let's say I want to ensure inbound email traffic has priority. In the configuration below for the Linksys LRT224, I've created a rule where inbound POP3 traffic (TCP port 110), which is standard email traffic from an email server, is given high priority on both the WAN1 and WAN2 interfaces. This means that if there is congestion on either WAN interface, inbound email traffic will be permitted before non-prioritized traffic. Note, if the traffic type you want to prioritize isn't pre-defined on your router, you can probably define it. Many routers will allow you to add network applications based on protocol (TCP or UDP) and Layer 4 port number (0-65,535).
Traffic Priority - Linksys LRT224
Example 3: Let's say I want to ensure my Netflix streaming device has enough bandwidth for smooth playback. Netflix recommends 5 Mbps for HD quality streaming.
I would start by giving my Netflix device a static IP address on my network. On the Linksys LRT224, the default LAN network uses the 192.168.1.0/24 subnet, and the DHCP range is 192.168.1.100-192.168.1.149. Thus, I could give my Netflix device a static IP address of 192.168.1.150.
In the Linksys LRT224 rule shown below , I've configured both WAN interfaces to allow all traffic to 192.168.1.150 a minimum of 5 Mbps and a maximum of 6 Mbps. The goal in bandwidth management is to give the traffic-sensitive device(s) enough bandwidth, without limiting bandwidth for other devices and users too much. If my Netflix rule turns out to be too low, I can always increase the minimum and maximum values in 500 kbps increments until it works as desired.
Static Rule - Linksys LRT224
Dual WAN connections increase your Internet cost, so most of us aren't going to have them. However, if you're dependent on the Internet for communication, critical business applications, or other functions that can't tolerate an outage, dual WAN connections may easily be worth the extra expense. I hope the tips I've shared help you get the most from your investment.