Deploying more than one SDC for your tenant allows you to manage more devices without experiencing performance degradation. The number of devices a single SDC can manage depends on the features implemented on those devices and the size of their configuration files.
You can install an unlimited number of SDCs on a tenant. Each SDC could manage one network segment. These SDCs would connect the devices in those network segments to the same CDO tenant. Without multiple SDCs, you would need to manage the devices in isolated network segments with different CDO tenants.
The procedure for deploying a second or subsequent SDC is the same for deploying your first SDC. You can deploy the SDC using an SDC image that CDO provides or you can install a virtual machine or appliance from scratch and install the SDC on it. The initial SDC for your tenant incorporates the name of your tenant and the number 1. Each additional SDC is numbered in order.