March 24, 2011 at 14:04CodeFest IT infrastructure (WiFi, projectors, laptops, etc.)
Last weekend, a codefest.ru codefest.ru developer conference was held in our city .
We were lucky to be there among the organizers and be responsible for a number of infrastructure tasks.
WiFi
It was necessary to provide 4 WiFi zones with stable coverage inside the zones, as well as in the transitions between the zones on the flights of stairs and balconies.
We worked as follows:
To remove the load from access points, we used a regular desktop computer with three network cards, Ubuntu 10.04, with dnsmasq installed, and ferm as a preprocessor for iptables as a DHCP-DNS-Firewall server. As a safety net, transparent squid3 was also located under the pairs on the server . In the case of a shelf on the channel, I would have to use it, but it was not necessary, despite the abundance of student hostels around and, most likely, their misuse of our strip.
All our points worked in bridge mode. On the ground floor of the building there was no physical opportunity to route the cable from the server to the access point, so we used the usual USB whistle from a megaphone. The second, third and fourth floors used the usual cable Internet.
Equipment used
Open access points:
Zyxel 330w EE with Wive-NG - 2 pieces combined in WDS,
Asus WL500-gP and D-LINK 320 with dd-wrt,
NetGear WNR3500L
Closed access points:
Asus RT-N10 with stock firmware, c wpa2 for administrators.
There are no complaints about the work of all these points. There were 3, 6, 11 channels making noise in the building, so we decided not to use them at all.
The first floor worked autonomously from a megaphone whistle plugged directly into the NetGear WNR3500L access point with Tomato DualWan firmware (the firmware was downloaded from here ). The maximum that we were able to squeeze out of this Internet was one and a half megabits with 4 divisions of the antenna, so the Internet on the ground floor was distinguished by high latency and excessive thoughtfulness.
But from the switch on the floors above we got a 10 megabit cable, then our server distributed two / 23 subnets for the second and third floors. All laptops on the scenes, administrators gadgets were registered in dnsmasq statically with bindings to mac-addresses, the rest was given dynamically. In the configuration examples, this point is cut out. Configs dnsmasq and fermwith comments. 5min statistics on arp and dhcp-leases were removed from the server interfaces .
As a result, in two days we registered about five hundred unique devices, 10Gb of consumed traffic in our network.
Projectors and other
VGA output from the projector in the largest hall was located in the operator’s service room on the fourth floor, far from the stage, so the speaker’s laptop (WinXP) had to be connected via RDP (Windows Remote Assistance) with the laptop on the fourth floor. There was also the server itself, UPS, switch, open access point, another open point with WDS and one service. The remaining points were scattered around the building to provide the largest coverage area. As a WiFi analyzer, Wifi Analyzer from the Android market was used.
We physically could not provide several hundred people with autonomous outlets, so we bought 4 dozen of the simplest extension cords in Ikea and just scattered them in the halls, for those who managed to.
Broadcasting
D-Link DCS-2121 and vlc as a streaming server were used as webcams. Unfortunately, vlc did not work out of the box as I wanted, I had to reassemble it manually. Done on this article , thanks to the author.
The only problem in the case of broadcasting was the poor quality of the channels from the backbone operator and a completely inadequate traceroute through, for example, Amsterdam, Telia and other black holes for packets. To solve the problems, it was necessary to reduce the bitrate, quality and increase the number of key frames. Example of configs for a streaming server .
We will be happy to answer all your questions and comments.
We were lucky to be there among the organizers and be responsible for a number of infrastructure tasks.
The solved problems.
- Organization of WiFi Internet access for ~ 1000 users in a four-story building,
- ensuring the operation of the entire infrastructure: projectors, presentations, guest outlets, etc.
- Broadcast from two webcams to the Internet.
WiFi
It was necessary to provide 4 WiFi zones with stable coverage inside the zones, as well as in the transitions between the zones on the flights of stairs and balconies.
We worked as follows:
To remove the load from access points, we used a regular desktop computer with three network cards, Ubuntu 10.04, with dnsmasq installed, and ferm as a preprocessor for iptables as a DHCP-DNS-Firewall server. As a safety net, transparent squid3 was also located under the pairs on the server . In the case of a shelf on the channel, I would have to use it, but it was not necessary, despite the abundance of student hostels around and, most likely, their misuse of our strip.
All our points worked in bridge mode. On the ground floor of the building there was no physical opportunity to route the cable from the server to the access point, so we used the usual USB whistle from a megaphone. The second, third and fourth floors used the usual cable Internet.
Equipment used
Open access points:
Zyxel 330w EE with Wive-NG - 2 pieces combined in WDS,
Asus WL500-gP and D-LINK 320 with dd-wrt,
NetGear WNR3500L
Closed access points:
Asus RT-N10 with stock firmware, c wpa2 for administrators.
There are no complaints about the work of all these points. There were 3, 6, 11 channels making noise in the building, so we decided not to use them at all.
The first floor worked autonomously from a megaphone whistle plugged directly into the NetGear WNR3500L access point with Tomato DualWan firmware (the firmware was downloaded from here ). The maximum that we were able to squeeze out of this Internet was one and a half megabits with 4 divisions of the antenna, so the Internet on the ground floor was distinguished by high latency and excessive thoughtfulness.
But from the switch on the floors above we got a 10 megabit cable, then our server distributed two / 23 subnets for the second and third floors. All laptops on the scenes, administrators gadgets were registered in dnsmasq statically with bindings to mac-addresses, the rest was given dynamically. In the configuration examples, this point is cut out. Configs dnsmasq and fermwith comments. 5min statistics on arp and dhcp-leases were removed from the server interfaces .
As a result, in two days we registered about five hundred unique devices, 10Gb of consumed traffic in our network.
Projectors and other
VGA output from the projector in the largest hall was located in the operator’s service room on the fourth floor, far from the stage, so the speaker’s laptop (WinXP) had to be connected via RDP (Windows Remote Assistance) with the laptop on the fourth floor. There was also the server itself, UPS, switch, open access point, another open point with WDS and one service. The remaining points were scattered around the building to provide the largest coverage area. As a WiFi analyzer, Wifi Analyzer from the Android market was used.
We physically could not provide several hundred people with autonomous outlets, so we bought 4 dozen of the simplest extension cords in Ikea and just scattered them in the halls, for those who managed to.
Broadcasting
D-Link DCS-2121 and vlc as a streaming server were used as webcams. Unfortunately, vlc did not work out of the box as I wanted, I had to reassemble it manually. Done on this article , thanks to the author.
The only problem in the case of broadcasting was the poor quality of the channels from the backbone operator and a completely inadequate traceroute through, for example, Amsterdam, Telia and other black holes for packets. To solve the problems, it was necessary to reduce the bitrate, quality and increase the number of key frames. Example of configs for a streaming server .
We will be happy to answer all your questions and comments.