Mesh network presentation
5 likes3,862 views
The document discusses mesh networks, which are wireless networks formed by connecting nodes without centralized administration. It describes the topology and attributes of mesh networks, including that they are self-organizing, self-healing, and scalable. It then provides examples of several existing mesh networks around the world and discusses some of the technical and community challenges in building mesh networks.
Mesh network presentation
- 1. Mesh Networks | Hacking The T3lc0 Model http://arig.org.il
- 2. What's a Mesh Anyway ? Mesh = topology. anything not a star / bus / ring / tree Nodes = routers, smart phones, cars – anything wi-fi enabled Links = wireless connections Mesh Network Attributes: Self-organizing Self-healing Scalable Robust, hard to disconnect
- 3. Mesh Node Recipe 1x 802.11 compatible radio device 1x radio driver, eg. atheros 1x Foss OS: eg. OpenWRT 1x Mesh Protocol BGP, layer 7 ( uses TCP, port 179 ) & OSPF ( IP datagram encapsulated ) OLSR, layer 3 ( uses UDP packets ) B.A.T.M.A.N, layer 2 ( raw ethernet frames, kernel module)
- 4. Radio Use of public 2.4GHz & 5GHz bands No special license to operation 3.7GHz also recently made available Open Spectrum: public radio frequency access Open Source Cell Phone Network at $2 per month
- 5. Mesh Protocols Protocol Tasks: Node announcement Neighbor sensing Routing table upkeep Routing decisions Protocol Efficiency Metrics maximize: raw data minimize: control Data / ( control Data + raw Data ) > 70 implementation, lots of academic Interest
- 6. The Problem Present Routers, No Inter-Communication Low Service Improvement Incentive Centralized Power, Censorship No Service Improvement Incentive Infrastructure Vulnerability: Crisis Scenarios Cellular Service Failure (Cellcom, 2010)
- 7. The Solution part of a Solution: Mesh Network Open Mesh: Open Source, Open Standards Affordable Community Owned User Operated Induce ISP Service Improvement (mozilla effect)
- 8. History, by Device: WRT54G Story of the Source Code: 1. Andrew Miklas posts on the Kernel Mailing List: # dd if=WRT54G_1.02.1_US_code.bin of=test.dump skip=24577c bs=32c # mount -t cramfs test.dump /mnt 2. GPL requires Linksys to publish source code 3. pressure... 4. $$$ profit! : Linksys open sourced the WRT54G firmware in July 2003 A 60$ turns into a 600$ corporate router ! Unlocked features: shell access, run VPN / VoIP servers, use as a repeater or a bridge → mesh possible
- 9. History, by Device - XO-1 100$ laptop per child Project Mesh to Provide Classroom & Village connectivity Partial 802.11s implementation ( no security for example ) Plug-n-Play, at least in theory: # iwconfig msh0 mode ad-hoc channel 13 essid hello-mesh-world # ifconfig msh0 <IP address> Disappointing real-world performance Low powered radio → short range
- 10. History, by Network: Consume.net England, 2001, 1000+ list members, ~200 nodes Context: dialup, 512Kbps = $60,000 Clink Street Building Internet Sharing: Artists, Photographers, Filmmakers, etc. Expand to 2nd building → cross a 5m wide street: running cables across the street is illegal ! Buy a $4000 Breezecom AP10 ( 2Mbps, 100 users, 4 years uptime! ) Low cost, 802.11b PCMCIA cards motto: Consume the net !
- 11. Pico-Peering Agreement Written by the Consume.net founders. Key points: Free Transit: Owner agrees to provide free transit across their free network. Owner agrees not to modify/interfere with data as it passes through their free network. Open Communication: The owner agrees to publish the information necessary for peering to take place This information shall be published under a free license The owner agrees to be contactable and will provide at least an email adress No Warranty Terms of Use: The owner is entitled to formulate an 'acceptable use policy' This may or may not contain information about additional services provided
- 12. History, by Network: Freifunk Germany, 2002 Context: Post Unification, East-Germany: Fiber Internet project: 1. rip out all PSTN copper 2. install fiber lines Project budget overrun → end users left with nothing ! Early Start: PCs on rooftops Very fast adoption Active today, strong hacking culture
- 13. History, by Network: AWMN Greece, 2002 Small group of dissatisfied tech'ies ~1120 backbone nodes, > 2500 ap clients DIY mentality
- 14. History, by Network: Guifi.net Catalonia, 2004 Context: poor Internet access in rural areas ~13.500 nodes - likely the biggest in the world Lots of accumulated experience Strong community back
- 16. Mesh Network Services Network wide: IP assignment, DNS Mass Communication: VoIP Municipal Notification Service, e.g. Shderot Broadcast, Multicast: local radio, podcasts, etc. P2P services: file sharing, social networks Distributed Services: cache, backup, DNS Sensor Networks
- 17. In the News... Mediterranean, 2008: Submarine Cable Disruption 5 ! cables cut Israel only connected with two Israel, Dec. 2010: Cellcom Service Downtime Egypt, Jan. 28 2011 ( see also: Yeman, Lybia, Syria ): Internet shutdown. nothing fancy, simply power off ! Disruptions third world exclusive? no: Aug. 2011, San Francisco: BART cut cell service to avert protest US, 2011, State Department: spending > $70 million on “shadow networks”
- 18. Israel, 2011: Internet = '? קוטג Users forced into dual subscription: ,ספק, תשתית the only country ! Slower speed = more money Private, al la 'NGN' style user separation
- 19. 'Israel, 2011: The 'Law : תיקון חוק לשון הרע חשיפת פרטי גולשים:
- 20. Are we happy with this design ?
- 21. פרוייקט אריג Israel is way behind - about ~10 years ! Vision: Open, Community dedicated mesh =! אריגISP ISP, אריגco-existence Community owned, operated Learn from past attempts Israeli housing protest: inter camp connection effort Global Cooperation - Funkfeuer.at: CNDB ( common node DB schema ) development Borrowed public IPv6 block
- 22. Technical Challenges Spectrum Congestion Limited Wi-Fi Range Central Network Services: Node ID Assignment: IP / MAC DNS Servers Layer 8: User Resource Sharing
- 23. Sustainability is Key ++node operators, not nodes. ++mesh communities, not mesh networks.
- 24. Security OpenWRT Dual-Mode: WPA enabled private network Ad-hoc public network Is an open AP really a security risk ? Preventing, dealing with abuse Security at the protocol level: GNUnet
- 25. The End, Thank You http://arig.org.il