Network survivability is also called network protection and restoration, which targets to protect a network to survive any network failure, which involves a span failure, node failure, or even SRLG failure. From the simplest techniques to the most advanced ones, network survivability can be implemented in various fashions, which are tradeoff in the aspects of restoration speed and the cost for redundant protection capacity. The techniques include 

• 1+1/1:1 protection 
• Ring based techniques: BLSR and UPSR
• Span restoration
• Shared backup path protection
• Path restoration
• p-cycles
• Flow p-cycles
• Path segment path and restoration