VRRP: Increasing Reliability and Failover with the Virtual Router Redundance Protocol

Appendix D. SDL Overview and Flowcharts for VRRP

Specification and Description Language (SDL) is a formal language devised for the specification and description of different kinds of systems. SDL has been developed and standardized by CCITT (Comité Consultatif International Télégraphique et Téléphonique), with its new name ITU-T (ITU stands for International Telecommunication Union; ITU-T stands for ITU Telecommunication Sector). SDL has been standardized as ITU-T Recommendation Z.100.

SDL is a mature specification language; its conception goes back to the early 1970s. Its first version was released in 1976 and updated subsequently in 1980, 1984, 1988, 1992, and 1996. The 1992 version incorporates important additions such as the inclusion of ...