This book is the case-study based demonstration of formal specification (modelling) and verification of distributed communication protocols as specified by NASA. The aim of this work is to model and verify the given informal model preserving its complete properties and behaviours. We have used model based specification and verification methodology, which is widely used to verify certain behaviours of such protocols. The proposed formal model is adequate and its various properties can be verified using standard model checking/verification tools. This formalism is developed by finding inconsistencies in the given model and then removing them in the proposed model. All the protocols are positively tested for their specifications (as specified in the Specification Document). The developed model can be generated using any CASE tool in XMI, which can later be used by model checkers. This work was supervised by Reiko Heckel.