Better Bandwidth Management

Any amount of Internet bandwidth can become insufficient if not managed properly. That’s why most network managers rate bandwidth management very high on their list of priorities. There are various solutions available for the task, both software and hardware, free as well as commercial. Here, we talk about the bandwidth management capabilities of Microsoft ISA Server 2000. You’ll also need a Windows 2000 server in order to use it. 

Microsoft ISA server, as most of you would already know, is a firewall cum proxy server, which even does bandwidth management. If you’ve not already implemented it, then you’ll need a Win 2000 Server with SP2 and two network cards installed–one to connect to your Internet gateway and the other for your local network. Now assign a public IP address (given by your ISP) to the external card and a private fixed IP to the internal card. Next configure the server to act as your Internet gateway. For this, go to Start>Programs>Administrative Tools>Routing and Remote Access and select the server icon from the left panel. Right-click it and select the option “Configure and Enable Routing and Remote Access”. This will launch a wizard from where you need to select the Internet connection sharing option and select the type of connection you’re using to connect. 

Enter the range of IPs in your network

With this your gateway is ready. Now, install Microsoft ISA server. During installation, select Integrated Mode and then you will be asked to fill the range of internal IP address, which you are using on your network. This is so that every IP in the pool can be filtered through the IAS server. For a simple setup, click Construct table, which will automatically build the IP pool for internal and external IP on your network. After Installing Microsoft ISA server, configure it according to your organization requirements such as which IPs and protocols to allow/disallow on your network. 

Create new bandwidth rules

Configure Bandwidth Priority 



ISA server doesn’t control the amount of bandwidth being used. It only prioritizes the traffic according to the rules you set. These priority rules can be based on IP address or users/groups in your NT/2000 domain. You could use IP addresses to give priority Internet access to users who have fixed IPs in your organization. For those getting dynamic IPs through DHCP, you’ll also need to create rules based on user accounts in the domain. You can divide the users into groups and then associate those groups with the bandwidth rules. Let’s see how to create the priority rules.

Set new bandwidth priority according to your organization’s needs

Open ISA Management console from Start>Programs. Then double-click on the server icon located on the left side of the window. Next double-click on Policy Elements and right-click on Bandwidth Priorities. Then choose New>Bandwidth Priority from the menu. A new window will appear. Enter any name to it (for example low, high) and give a description in the description box. After this you will find two text boxes for specifying outgoing and incoming value ranging from 1 to 200. Fill these text boxes with the value. A higher value gives higher priority and lower value denotes lower priority. Finally click Ok to finish. 

Creating Bandwidth Rules



Creating rules in ISA server is very simple with the given wizard. Open Microsoft ISA Server’s Management console.

Double-click on server icon to expand its tree, right click on Bandwidth Rules and select New>Bandwidth Rule. This will run a wizard, asking you the name for the new rule. Give a suitable name to it and click next. The wizard will now ask you to select the protocols you want to prioritize and click next. Here you can choose the time when the priority should be activated, keep it to Always and click next. Now you need to set the client type, who will be accessing the bandwidth. This will throw up three options–Any request, Specific computers, and Specific users and groups. The first is self-explanatory. In the second, you must specify IP addresses of the clients, while in the third option, you need to specify the user names in your domain. Finally click, the Finish button to complete the process. With this, your bandwidth rules are all set. 

Sanjay Majumder