Internet and the Guanajuato International Film Festival
The Computer Corner
By Charles Miller
This week San Miguel de Allende once again welcomes the Guanajuato International Film Festival to town. I urge everyone to visit the web site at www.giff.mx to download a schedule then plan to attend as many of the films as possible. For the staff at GIFF and for the many international visitors who participate in the festival, access to the internet is a necessity, and this is where I sometimes become involved. For many years I have volunteered my technical services, to GIFF, mostly to help with IT problems around the office.
Admittedly some of these jobs can be challenging, such as the time I helped a French-speaking visitor with an uncooperative laptop. I do not speak French nor she English, but with both of us sharing Spanish as a second language we blundered our way through to a solution.
Volunteering with GIFF has been a beneficial experience for me because it has provided the opportunity to get some hands-on experience in some real-world situations I might not have a chance to see otherwise. The GIFF office here in San Miguel has your typical small office computer network adequate to serve the needs of the permanent staff, but once a year it turns into a virtual Grand Central Station operating 24/7 when scores of guests arrive to participate in the film festival. An urgent call came to me around 10 o’clock one night and when I arrived a short time later at Fábrica Aurora, even at that hour there were dozens of people in the office, and not all of them could connect to the internet.
One thing that has changed in the last few years is the proliferation of smart phones and with them the need for more wireless internet connectivity. Many typical “residential class” Wi-Fi access points have a set limit as to the number of wireless devices that may be connected, and when I started counting laptops and smart phones I saw in the GIFF office that night I quickly realized we were probably over the limit. In the case of their router, the number turned out to be 32.
Whenever any device connects to a network, wired or wireless, there is something called a “DHCP Lease” assigned to it. Most routers will assign a lease to an IP address for a device , such as a smart phone, for several days or a week because that is a good way to maintain its connected state and so that the router does not have to do all the work of setting up an IP address for that user again soon. This also means that no one else may use that IP address even if that smart phone leaves the premises and is therefore not using its IP address any longer. With a lot of people coming and going, this results in tying up a lot of the IP addresses so that when the available pool of 32 IP addresses was exhausted then nobody else could get one. This explains why someone who came into the office at 8am can connect their smart phone to the internet while the person standing right next to them who arrived 1 minute later cannot. The person who arrived at the office late might have arrived after all the IP addresses and DHCP leases had been used up. This is still true even if most of the people who had been using the internet had left the office.
Once this problem was identified I quickly reconfigured the wireless router to assign a DHCP Leases to last only a few hours. Even though this meant the router was doing a lot more work and much more often, it seemed to do the trick. For several reasons, this was only a temporary fix.
Coming up with some solutions to cope with last year’s problems was a good educational opportunity. This year we have put in place some hardware upgrades and procedural changes that should make everyone’s internet connection more reliable at the GIFF office. I hope they all work as planned and I will not get another late-night call, because I would much rather see you at the movies.
Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981 and now practically a full-time resident. He may be contacted at 044-415-101-8528 or email FAQ8 (at) SMAguru.com.