  Link and node failures are common two fundamental problems that affect
operational networks. Hence, protection of communication networks is essential
to increase their reliability, performance, and operations. Much research work
has been done to protect against link and node failures, and to provide
reliable solutions based on pre-defined provision or dynamic restoration of the
domain. In this paper we develop network protection strategies against multiple
link failures using network coding and joint capacities. In these strategies,
the source nodes apply network coding for their transmitted data to provide
backup copies for recovery at the receivers' nodes. Such techniques can be
applied to optical, IP, and mesh networks. The encoding operations of
protection codes are defined over finite fields. Furthermore, the normalized
capacity of the communication network is given by $(n-t)/n$ in case of $t$ link
failures. In addition, a bound on the minimum required field size is derived.
