Post on 15-Jan-2016
description
transcript
Ozone's Presentation to EU-Mesh
Ozone presentation
French Wireless ISP Founded in 2004... Goal : allow “Everywhere, EveryTime, Cheap and Effective
connectivity” and build a pervasive network Wifi was at that time the obvious choice for developing the network
(cheap, widespread, flexible, no licence) but Ozone is fundamentaly technology agnostic
...and bought in 2007 by Neuf Cegetel Neuf Cegetel is the French second major Telco and ISP 3000 employees Counts with 4M DSL clients (retail) Important market share in Business clients …To be bought by SFR, second French mobile Operator, within
weeks…
Network logic (1)
Antennas on rooftops to provide a local coverage We don’t pay for accessing rooftops : we gain access through
individuals “offering” their rooftop in exchange of free access to our services
They also power the installation (~20 W) 5 Radio cards on each roof :
3 * 2.4 GHz (=3 * 120 °) for clients connections 2 * 5 GHz for backhauling functions
Multiply roofs to offer a full coverage of the city About 1000 roofs to provide a first mapping of the city (105 km²) / Each
roof covering ~ 200m radius circle Full coverage provided through additional deployments (Urban furniture,
lamposts…) Backhaul roofs with efficient and affordable
technology Provide symmetrical Throughput
At least 8 Mb/s on each roof Mainly Wireless Point to Multipoint using 5GHz (802.11a)
Free licences, good throughput, cheap hardware Needs Line Of Sight (LOS) between roof and Concentration sector
…but also ADSL, Fiber, Wimax (when no LOS)
Network logic (2)
Each roof is connected to a concentration sector Through a 5GHz link based on 802.11a
A concentration sector is a sector antenna connecting up to 8 roofs
About 25 Mb/s IP available at each sector antenna to dispatch among roofs
Concentrations sectors are located on high buildings in Paris
9 of these building today Each building connected to the internet through fiber
Up to 20 concentrations sectors per building Limited by frequency reusability
Each roof might connect another roof itself Handy for sites that don’t have LOS to Concentration points
Clients
3 plans 18 € for unlimited monthly access
About 2500 clients each month 7,8 € for a daily pass
About 1000 clients 1,5 € for a 1 hour pass
About 6500 clients
About 10K users more at partners sites Deal : indoor coverage and free internet access in exchange of roof
access Museums
- Palais de Tokyo- Museum of Modern Art Centre Pompidou
Hospitals, Firms, associations
250 roofs
Today’s network (01/2008)
Concentration Sector
roofs
Roof with no LOS
Concentration Sector focus
RSSI :
RSSI > -70 dBm
On both side.
DSL as backhaul
Standard DSL link used Up to 20 Mb/s DL | 1 Mb/s upload
Tunnels used to hide the DSL layer Allows to monitor transparently the roof connected The user has no knowledge he is using a DSL link
A typical roof (1)
Omni-directionnal Antenna (5GHz)
Sector Antennas (2.4 GHz)
Directionnal Antenna (5GHz)
Outdoor Case
A typical roof (2)
Concentration sectors
Sector Antennas (5 GHz)
Directionnal Antennas (5GHz)
Hardware
Mikrotik Boards RB532A (discontinued now)
MIPS architecture 64 MB SDRAM 3 Mini-PCI slots ~50 % CPU load on concentration sector with high throuput (~15-20 Mb/s)
RB600 PPC architecture (400 MHz) 64MB SDRAM 4 Mini-PCI
« daughter boards » plugged to main board To add Mini-PCI slots and reach 5 Wifi cards per roof
Wifi Cards Atheros chipsets (AR5213 baseband / AR5112 RoC) 802.11 a/b/g Tests ongoing on 802.11n
Seems especially interesting for enhancing coverage in Ozone’s case
Antennas 2.4 GHz sectors (120°) 5 GHz sectors / directionnals / omnidirectionnals
Software
Mikrotik RouterOS Handles Point to Multipoint topology nicely
Important in our Backbone to avoid the « hidden node » problem No Open source philosophy here
A problem to integrate innovative solution
OpenWRT On roof using DSL as a backhaul link
OpenVPN not well implemented on RouterOS
At the IP Level
All the network is routed OSPF in the backbone
Up to concentration sectors Then static routing
BGP peering with Tier 1/2 provider FreeBSD server running bgpd and ospfd
QoS introduced Assuming each roof has 8 Mb/s, traffic prioritization
Snmp, ssh DNS, small packets (ACK), SIP Web, mail Other traffic P2P
Problem is we don’t know actually what throughput is available at a given time on the wireless backhaul link
Authentification Radius & MySQL databases
FreeRadius used Proxy services offered to partners (T-Mobile, Neuf Cegetel…)
Operations / Management
Deployment Made through Third parties contractors which have limited but
necessary knowledge of the network Implies they have a PC while deploying to verify antennas orientation,
radio association, etc…
Monitoring and maintenance SNMP Through Open Source softwares
Nagios for Network surveillance, availability reports, network instant trends
Cacti for graphing
Own developped tools for mass configuration / maintenance
Services
Services offered Standard internet access
Throughput offered may vary according to the client's connection quality with the infrastructure and overall load ; goal is to provide 2 Mb/s symetrical
Telephony SIP based ; we operate our own SIP proxies and have a PSTN connection
through a business partner- SIP Proxies based on Asterisk and SER
We offer as well SIP transit services to partners (Neuf Cegetel mainly…)
About to launch Geo-localisation services
Through IP based localisation : 200m precise in Ozone’s case Through third party software : cf www.loki.com
“Mobility” services Integrating various backhaul technology transparently for the users
through tunnels- OpenVPN based (transparent to user)- Overhead might be a problem (up to 20% up to now)
Deployment relevant to EU-Mesh
100 lamposts in Paris To be deployed end of May Each lampost will be equiped with a 3 radio AP
1 * 2.4 GHz radio (802.11 b/g(/n)) for clients connectivity 2 * 5 GHz radio (802.11 a) for backhaul
Lampost might be backhauled by 5GHz link (Ozone network) ; majority of them DSL link (directly or through wireless hop) Wimax link
Goal is to provide seamless mobility for clients moving from lamposts to lamposts
In some area, we will deploy APs on up to 10 lamposts 100m distance between each lampost in these areas Mobility will be checked with Surf and VoIP
- Either through tunnels, or WDS
In the same area, different backhaul solution might be adopted simultaneously
Lampost deployment
5GHz 5GHz 5GHz 5GHz 5GHz
PoE PoE PoE PoE PoE PoE
Ozone
100 m 100 m 100 m
EU-Mesh trials could be done on a portion of this deployment
Comparison of EU-Mesh and standard 802.11 networks
Network flaws (some of them…)
Coverage is still low A way to enhance coverage in a cheap and convenient way would
be very helpfull No Mesh in the network
Deployment could be a lot easier Mesh network implying zero-configuration during installation would be a
great feature for us Auto-reconfiguration on failure would be a very interesting feature
Though our antennas are fixed, we have an Omni-antenna we could benefit from to enhance resilience in the network
Other hardware configuration could be studied and deployed to enhance resilience
- Though major cause for outages in our network is power shortcuts
« Dumb » network Poor QoS settings
Beeing able to locally manage QoS (based on actual Throughput) and have information on a full path (and not only a node) from a QoS point of view would be a very appealing feature
No interferences handling Neither at 2.4 GHz nor at 5 GHz