With the standard kernel source, you may have only one EQL device per machine. Often it is cheaper to use multiple lower speed lines than to have one high speed line installed. Linux, Livingstone Portmasters and newer dial-in servers support compatible facilities.
Configuration is fairly straightforward.
You start by configuring the eql interface. The eql interface is just like any other network device. You configure the IP address and mtu using the ifconfig utility. Next, you need to manually initiate each of the lines you will use. How you initiate the connections will depend on what sort of link they are.