1. A method performed within a network element, comprising: receiving new software to be installed on the network element having an active controller card and a backup controller card, wherein the new software comprises metadata describing a format used by the new software to store and access state information of the network element; installing the new software on the backup controller card; synchronizing an active state of the network element on the backup controller card, wherein the active state is associated with an old software running on the network element; and translating the active state that is synchronized on the backup controller card using the metadata to the format used by the new software, wherein the active state that is translated using the metadata includes at least one of a traffic forwarding table, user session information, and subscriber session information, wherein the active state that is translated has been dynamically built up during runtime and is used to control how the network element handles data traffic, and wherein the metadata that is used to translate the active state describes a structure and fields of an active state data structure to be used by the new software, wherein the translating further comprises performing at least one of: translating data from fields of an active state data structure used by the old software to fields of the active state data structure used by the new software that have been rearranged relative to the fields of the active state data structure used by the old software; and assigning a default value to a field of the active state data structure used by the new software that is not found in the active state data structure used by the old software.