Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Multiprotocol Label Switching wikipedia , lookup
Cracking of wireless networks wikipedia , lookup
Deep packet inspection wikipedia , lookup
Cellular network wikipedia , lookup
Zero-configuration networking wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Internet protocol suite wikipedia , lookup
Communication protocol wikipedia , lookup
Protocol Verification for Cellular Networks Chunyi Peng The Ohio State University 2 Protocol Verification is Gaining Momentum 2 Protocol verification for the Internet Since 1990s Single protocol with implementation Emerging techniques for network verification E.g., Anteater [SIGCOMM’11], Head Space Analysis[NSDI’12], NICE [NSDI’12], Alloy[SIGCOMM’13], NetCheck[NSDI’14], Software Dataplane [NSDI’14] … Largely unexplored territory in cellular networks 2 E.g., [Cohrs’89, SIGCOMM], [Holzmann’91], [Smith’96], TCP [NSDI’04], Routing[SIGCOMM’05], … Few efforts, e.g., 2G handoff [Orava’92], Authentication [Tang’13] Case for PV in Cellular Networks 3 Historically, cellular network protocols did not go through rigorous screening by the research community Cellular Protocol Characteristics Technical Challenges Key Research Aspects Many Protocols for Cellular Networks 4 Control-plane protocols as an example Connectivity Management (CM) Mobility Management (MM) Radio Resource Control (RRC) Layered protocol stack Circuit Switching (CS) Mobile Switching Center 3G 3G Gateways Packet Switching (PS) 4G Mobility Management Entity (Control Node) Many Protocols for Cellular Networks 5 Control-plane protocols as an example CS Domain PS Domain Connectivity CM Management CM (CM) Mobility MM Management MM (MM) Radio Resource Control (RRC) Layered protocol stack Spanning both CS and PS domains Circuit Switching (CS) Mobile Switching Center 3G 3G Gateways Packet Switching (PS) 4G Mobility Management Entity (Control Node) Many Protocols for Cellular Networks 4G 3G 6 Control-plane protocols as an example CS Domain Domain PSPS Domain CM CMCM MM MM MM Radio Resource ControlRRC (RRC) Layered protocol stack Spanning both CS and PS domains Operating in hybrid 3G/4G deployment Circuit Switching (CS) Mobile Switching Center 3G 3G Gateways Packet Switching (PS) 4G Mobility Management Entity (Control Node) Complex Protocol Operations 7 Protocols work together to offer vital 3G/4G utilities Rich patterns along three dimensions cross-domain cross-layer cross-system CS Domain PS Domain PS Domain CM CM CM MM MM MM Radio Resource Control RRC 3G 4G Challenge #1: Partial Access to Protocol Operations 8 Distributed protocol operations at both Cellular infrastructure (base stations, MME, gateways, etc.) Mobile devices Partial access Pretty “closed” core infrastructure More efforts needed on the 3G mobile device side 8 Circuit Switching (CS) MSC Closed Core NetworkPacket Switching (PS) 3G Gateways 4G MME Challenge #2: Design & Operation 9 Verification problems stem from both Design specifications Operations Implementations Common-case vs Worst-case No well-defined common cases Lack of wireless net benchmarks Circuit Switching (CS) MSC 3G Norm rather than exceptions 3G Gateways Temporal-Spatial dynamics: Mobility, dynamic radio links Packet Switching (PS) 4G MME Challenge #3: Intra- and Inter-PV 10 Protocol Verification Intra-protocol operations Inter-protocol interactions cross-domain cross-layer 10 cross-system CS Domain PS Domain PS Domain CM CM CM MM MM MM Radio Resource Control RRC 3G 4G Rich Protocol Interactions 11 Complex interactions in common scenarios Inevitable interplay between radio, mobility, data/voice Diagnosis over one layer/domain/system is Concurrent voice and data use insufficient 3G/4G switch due to hybrid deployment, mobility, voice Two causes of problematic interactions defects Operation/Implementation Single-type test fails to slips unveil both issues Circuit Switching (CS) Design MSC 3G 3G Gateways Packet Switching (PS) 4G MME Research Topics 12 Many Topics remain: New PV Methodology for Cellular Networks (in)Validation of Results Software Tools for Automated Verification Verification for “Results from Protocol Verification Research” Needs community testbed and data archive We are still at starting stage of PV research