* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Slides: Challenges in Mobile Networking
Survey
Document related concepts
Net neutrality law wikipedia , lookup
Network tap wikipedia , lookup
Computer security wikipedia , lookup
Policies promoting wireless broadband in the United States wikipedia , lookup
Computer network wikipedia , lookup
Wake-on-LAN wikipedia , lookup
Airborne Networking wikipedia , lookup
Zero-configuration networking wikipedia , lookup
Distributed firewall wikipedia , lookup
Deep packet inspection wikipedia , lookup
Recursive InterNetwork Architecture (RINA) wikipedia , lookup
Wireless security wikipedia , lookup
Transcript
Research Challenges in Mobile Networking and Computing Thomas F. La Porta Professor, Department of Computer Science and Engineering Penn State University Outline • Overview of Mobile Networking and Computing • Mature Research – Micro-mobility – System interworking • Open Research Topics – Security proposal • Summary 0 Mobile Internet - Ubiquitous Communications and Computing Wireless access to networks will soon be the most popular method • Today: 850M phone lines, 700M wireless subscribers • Wireless growth far exceeds wired growth Internet is driving network growth 33 Global Access Lines (billion) • Internet users still doubling yearly Ubiquitous wireless data has stalled… • low data rates • limited terminals 22 wireless Wireless Cable cable Wireline wireline 11 • limited applications …Mobile computing has not • lap tops are everywhere 0 0 1958 1958 1978 1978 2005 1998 20 • dial-up service is pervasive Hindered by low performance, poor connectivity, and inconvenience 1 Mobile Communications Today: Tale of 2 Networks Cellular Telecommunications Network Radio Telephone Network Wireless Controllers Wireless Gateways Internet • Network tailored for voice – very low bandwidth • Devices not suitable for Internet and computing applications Despite high penetration & coverage, Internet access has fizzled Telephone Network The Internet – Wireless Enterprise Networks Radio Edge Router Access Router Internet • Network tailored for best-effort data traffic – high bandwidth, no controls • Supports general computing and data networking applications Gaining high density in hot-spots, but no ubiquitous coverage 2 Evolution to Multiservice networks 3G Cellular Networks • Outdoor Areas • High Mobility Radio Controller Aggregation Router Access Router Presence Enterprise Location Networks Access Router • 802.11++ Core Internet • Local Mobility Backbone • Packet Voice Aggregation • High Data Rates Authentication Router 4G Air Interface 4G 4G Radios Radios Access Router Urban Networks • Broadband Distribution Networks • High Speed Pico Cells Aggregation Router Ad Hoc • Allow People to network Networks • Self Configuring Home Networks • DSL/Cable • High Speed Internet Access • End-to-end Internet – common mobility management and control – common transport infrastructure – common services infrastructure Unifies various technologies (wireless, wireline, mobility) 3 Examples of Individual Multiservice Networks Wireless Networks • 1980’s – voice services • 1990’s – voice services with very limited data capabilities (e.g., short messaging) • 2000’s – 3G multimedia networks (voice, data, multimedia) Internet • Original use – best effort data (email, remote login, file transfers) • 1990s – some multimedia (video and audio streaming, conferencing) • 2000’s – merging of data, voice, and multimedia (Internet telephony in enterprises) Next trend (already ongoing): merging individual networks • Impacts: – transport – control protocols – services infrastructure – management – security 4 Merging of Networks Many challenges due to diverse applications, legacy systems, and philosophies • Voice (aka Public Switched Telephone Network) and Data (aka The Internet) Characteristic Classic Voice Switching Circuit (all reserved) End Devices Dumb Classic Data Packet (queuing) Smart Intelligence Network-based Services For connections, billing Client/Hostbased Applications Comments Classic, old problem Mixed with wireless Starting to change Starting to change • Public and Private (corporate networks) Characteristic Public Management End-to-end Security Left to end systems Performance Best effort Billing Private Based on need Used to be closed Typically, good None, simple Comments Coordination Big problems, + wireless! Need to share Gaurantees? • Interworking is a big problem – service definitions, protocols, profiles, … End result: Telephone network will get dumber, the Internet will get smarter 5 Where are we? Seamless high-speed ubiquitous network access • new access technologies – many already exist • mobility between networks – active research area () Internetworking • drive towards common control paradigm – controversial () • interworking between networks – islands exist () • performance – new demands on network controllers Security • eCommerce, enterprise data, distributed computing – no one feels safe • authorization and accounting – bringing order to chaos Intelligence and Applications • distribution between network and end devices – solutions have been vertical 6 Where are we? Seamless high-speed ubiquitous network access • new access technologies • mobility between networks – real-time mobility – Handoffs – real-time location – Paging Internetworking Security Intelligence and Applications 7 Current Internet-Based Mobile Packet Networks: Mobile IP Permanent IP Address Temporary IP Address Regular routing Home Agent MD Radio Access Networks Foreign Agent Internet Host Intranet Foreign Agent IP Tunneling • Handoffs always managed by Home Agent – high update overhead – slow handoffs • 3G UMTS Network structure is similar – uses specially defined (non-Internet) protocols for mobility 8 Real-Time Mobility: Domain-based Mobility Internet Domain Router R R Domain Router R R R R R R R R R R MD Local mobility Local mobility • Distributed control: Enhanced reliability, better scaling • Localized mobility management: Lower overhead, fast handoffs • Based on IP protocols: Independent of access network Mobility across access networks 9 Real-Time Mobility: HAWAII for handoffs Internet Domain Router R R Domain Router R R R R R R R R R R MD Local mobility Mobile IP Local mobility • Distributed control: Enhanced reliability – recovery of lost state via Internet routing protocols • Localized mobility management: Lower overhead, fast handoffs – updates only reach routers affected by a movement • Minimized or Eliminated Tunneling: efficient routing, easy QoS – dynamic, public address assignment to mobile devices Compatible with Mobile IP 10 HAWAII Overhead Domain Router/HA Router 1 ... Router 7 BS1 ... BS-20 BS1 BS20 Message HAWA II DR Msg/sec Hawaii Registration 127.8 Hawaii Updates 51.3 M-IP Registration 48.4 M-IP Updates 12.7 Total 240.2 BD RD r v LB TR Y TM g Mobile IP HA Msg/sec 0 0 574 127.4 701.4 Base stations/domain router 2nd level routers/DR User density User velocity Base station perimeter HAWAII refresh timer # of updates/message Mobile IP lifetime % users outside home domain rn MIP = L B B r p 2 L B 16 T + D 140 7 2 39 Km 112 Km/hr 10.5 Km 30 s 25 300 s 0.1 B D M H + rn = L B B + D p rn D p L B 16 T L BD B D M-IP M L B R B gr 2 D r + 2 B 16YTR Hawaii 11 HAWAII Handoff Delay: Packet Loss Audio (160B/20msec) 12 Real-Time Location: IP Paging • Motivation – dormant mode increases battery life considerably – mobile device must be located (quickly) to deliver data – currently each network type has unique paging protocols • Challenges – limit overhead (messages) while maintaining low latency – do not impact fast-path packet forwarding – devise scaleable solution in terms of network size and administrative domains – support various paging algorithms • Basic Solution – compatible with and leveraging IP protocols Determined by – distributed control for scale and scope Registration Determined by Paging MD Serving R Router/Switch Home Router/Switch Network Determined by address Host R R 13 Unified Paging HA initiates page Uniform mobility management – wireless LANs, outdoor Home Agent Internet R R Old FA initiates page Foreign Agent Mobile IP Foreign Paging Area Agent R Domain Paging Area Foreign Agent Any router initiates page 3 Options: • Home Agent Paging – Home agent buffers packets and initiates page to all Foreign Agents – Can be controlled by corporate network – Does not scale • Foreign Agent Paging – Last active Foreign agent buffers packets and initiate paging – Distributes load • Domain Paging – Fully distributed, very scaleable and reliable 14 IP Paging: Domain Paging Any router initiates paging Internet Domain Router IP Paging Area R R Domain Router R R R R R R R R R R • Basic Procedures – dormant MH does not send updates unless crossing Paging Area – packets sent to last known domain – any router in old path to Mobile Host may initiate paging • Characteristics – more complex: changes to routers in access network – excellent scaling: load distributed among all routers – excellent scoping: only routers in a paging area need topology information – excellent reliability: failed routers are routed around (OSPF) 15 IP Paging: Latency Results • Latency (from Stanford University Local Area traces) – Foreign Agent and Domain Paging scale best: distributed load – Domain paging slightly more scaleable (~10%): dynamic load balancing • Messaging Overhead – Domain Paging has lowest overhead: no paging related updates to Home Agent 16 Where are we? Seamless high-speed ubiquitous network access Internetworking • drive towards common control paradigm – Internet Control • interworking between networks – support for legacy systems (and stubborn operators!) • performance – efficiency Security Intelligence and Applications 17 Internet Control and Interworking: Unified Mobility Manager Provide Home Location Register and Internet functionality Current User/mobile location management HLR Cellular Integrate HLR/VoIP server functions Security control (authentication center, IP security server) Service profile DB management VoIP server IP security server Internet (VoIP) – mobility management – security – profile management • Support multiple interfaces – Wireless: ANSI 41, GSM / UMTS MAP – Internet: VoIP (SIP, H.323), AAA (RADIUS) Integrated User Profile Database Security manager MAP / SS7 Protocol Gateways • Integrate 3 key functions of HLR & IP (VoIP) servers User location manager VoIP / IP AAA / IP Cellular Internet ANSI41 / SS7 Cellular 18 Unified Mobility Manager: Architecture Core servers - Common functions across protocols - Interface via abstraction of basic services - Multiple server instances on a cluster of processors for system scalability - Interworking function between protocols: O(n) versus O(n2) complexity Protocol gateways - Perform protocol specific controls - Facilitate new protocol introduction Integrated user profile DB - Common database for a ‘user’ CDMA 2000 GSM/UMTS PG PG Wireless Data PG VoIP Servers PG Core Core Operations Servers Integrated user profile 19 UMM – Location Management Performance • 2 Basic Scenarios Considered: UMTS Network with HLR or UMM • 2 call scenarios – goal: calls travel over IP network – call from PSTN to UMTS phone (PSTN to cellular) – call from SIP phone to UMTS phone (Internet to cellular) PSTN call HLR/ UMM HLR & UMM are the same GW Switch Serving Switch PSTN BS SIP Call SIP Internet MGW HLR GW Switch PSTN Serving Switch BS SIP-HLR • uses PSTN for transport • inefficient UMM Internet MGW Serving Switch BS UMM Internet Serving Switch BS SIP-UMM • uses packet for transport • efficient SIP-UMM (SIP e2e) • most efficient 20 UMM Analytical Results • Migration to packet – short term: performance degradation from circuit/packet translation – long term: packet end-to-end improves performance 21 Research Topics: Intelligence For Network Transport Balance between simple networks and functional networks Ad Hoc Networks – self-configuration – very dynamic routing – Challenges: security, performance, relay networks to enhance cellular telecom Sensor Networks – power-aware component to most functions (routing, etc.) – nodes participate in processing information – Challenges: placement, distribution of functions Traditional Networks – multiclass admission control & charging algorithms – IP Services platforms (firewalls, web redirection, …) – Challenges: heterogeneous networks, network architecture Heterogeneous Networks – real-time mobility between networks – Challenge: vastly different network characteristics 22 Research Topics: Intelligence for Services Support for creativity, rapid deployment, and wide accessibility Network architectures – separation of transport and service control – re-use across network types – Challenges: scalability, performance, reliability Protocols – interworking across systems Services – legacy systems – Challenges: correct semantics, functionality mapping, software Heterogeneous networks – access from different networks – access via different protocols – Challenges: security, flexibility, performance Transport 23 Research Topics: Security Performance/Security Tradeoff Traditional Wireless • 3G data services require network-based enhancements • Challenges – limiting performance impact, or improving performance Ad hoc wireless, sensor networks • existing solutions are not scalable • Challenges – trade-offs of security and performance General • end-to-end security solutions, including network, devices, OS, … 24 Performance Focused Security Goal: Allow network-based performance enhancements in a secure environment • Specific Problem: Data performance in wireless networks is poor – network-based solutions have been proposed for 3G – caching has been proposed for ad hoc and relay networks – proposed solutions contradict security models for mobile VPNs • Sketch of solution – allow at least one intermediate “router”, positioned at the edge of the network, to view and process a portion of a secure packet – trade-off level of security for performance • Benefits – higher performance data services – access to network-based value added services with limited security trade-off 25 Security Solution for 3G: Mobile Multi-layered IPSec Client Wireless Router Network End-to-end encryption for payload Corporate Network Firewall } Host Example Concatenated encryption for control information • Define multiple zones in a packet (as in ML-IPsec by Zhang and Singh) – each zone has an associated security association (keys, etc.) – each zone may be terminated in one or more places inside the network • Research: Initialization, Mobility, Performance – distribution of keys and initialization – maintenance of security during mobility – performance impact – implementation issues 26 Ubiquitous Mobile Computing - Summary The potential still remains… …Hard work required – networking: end-to-end systems issues with access and core – intelligence: distribution between device and network (dynamic & flexible) – applications and support services: retain generality – new network architectures … with Imagination – new ways to use mobile capabilities – perhaps extension of wireline network paradigms is wrong!!! 27