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ddNF: An Efficient Data Structure for Header Spaces [chapter]

Nikolaj Bjørner, Garvit Juniwal, Ratul Mahajan, Sanjit A. Seshia, George Varghese
2016 Lecture Notes in Computer Science  
In order to scale to data-center networks found in Microsoft Azure we developed a new data structure called ddNF, disjoint difference Normal Form, that serves as an efficient container for a small set  ...  of equivalence classes over header spaces.  ...  The ddNF data-structure may likewise increase in size during an insertion.  ... 
doi:10.1007/978-3-319-49052-6_4 fatcat:t26vwiswrbbbdkzcw56vl5tiz4

A Precise and Expressive Lattice-theoretical Framework for Efficient Network Verification [article]

Alex Horn and Ali Kheradmand and Mukul R. Prasad
2019 arXiv   pre-print
The overhead of atomic predicates prompted ddNF to devise a specialized data structure of Ternary Bit Vectors (TBV) instead. However, TBVs are strictly less expressive than BDDs.  ...  To do so efficiently, the state-of-the-art (e.g., Veriflow) partitions packet headers with identical forwarding behavior into the same packet equivalence class (PEC).  ...  All element types in Figure 7 can be efficiently implemented using data structures that use contiguous memory, and our implementations have therefore high cache locality, similar to TBVs in ddNF.  ... 
arXiv:1908.09068v1 fatcat:cluc2xb7nra5pgso5plpo255am

Scaling network verification using symmetry and surgery

Gordon D. Plotkin, Nikolaj Bjørner, Nuno P. Lopes, Andrey Rybalchenko, George Varghese
2016 Proceedings of the 43rd Annual ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages - POPL 2016  
On the surface, large data centers with ∼ 10 5 stations and nearly a million routing rules are complex and hard to verify.  ...  Our network transformations exploit network surgery (in which irrelevant or redundant sets of nodes, headers, ports, or rules are "sliced" away) and network symmetry (say between backup routers).  ...  For this purpose we used a data-structure called disjoint decomposed normal form (ddNF) data-structure, described in [5] .  ... 
doi:10.1145/2837614.2837657 dblp:conf/popl/PlotkinBLRV16 fatcat:drjbwrdpffewlogtubea6syq2y

Scaling network verification using symmetry and surgery

Gordon D. Plotkin, Nikolaj Bjørner, Nuno P. Lopes, Andrey Rybalchenko, George Varghese
2016 SIGPLAN notices  
On the surface, large data centers with ∼ 10 5 stations and nearly a million routing rules are complex and hard to verify.  ...  Our network transformations exploit network surgery (in which irrelevant or redundant sets of nodes, headers, ports, or rules are "sliced" away) and network symmetry (say between backup routers).  ...  For this purpose we used a data-structure called disjoint decomposed normal form (ddNF) data-structure, described in [5] .  ... 
doi:10.1145/2914770.2837657 fatcat:q4n7srqz7zcwfn6kjt7vnpm6ii

APKeep: Realtime Verification for Real Networks

Peng Zhang, Xu Liu, Hongkun Yang, Ning Kang, Zhengchang Gu, Hao Li
2020 Symposium on Networked Systems Design and Implementation  
We thank the anonymous NSDI reviewers and our shepherd Behnaz Arzani for their valuable feedback. We thank Zunying Qin for help on collecting device configurations.  ...  BDD is a data structure that can canonically represent Boolean formulas, and it allows efficient logical operations including conjunction (∧), disjunction (∨), and negation (¬).  ...  In contrast, if we create range-based ECs based on match fields, we will split EC a into three ECs, each of which is a rectangle in the header space. Suppose another ACL rule R2 is inserted.  ... 
dblp:conf/nsdi/ZhangLYKGL20 fatcat:cgj4v6yp5bbz7mdvbfsssrazl4