The SoftLayer_Billing_Item_Network_Subnet data type contains general information relating to a single SoftLayer billing item whose item category code is one of the following:
* static_sec_ip_addresses (static secondary)
* sov_sec_ip_addresses (secondary on vlan, also known as "portable ips")
* sov_sec_ip_addresses_pub (sov_sec_ip_addresses public only)
* sov_sec_ip_addresses_priv (sov_sec_ip_addresses private only)
* sec_ip_addresses (old style, secondary ip addresses)
These item categories denote that the billing item has subnet information attached.