Building Your Own Teleconference System with Asterisk and Gizmo
Pages: 1, 2, 3, 4
Using Your System
Once your system is up and running, using it is really easy. Let's consider a school as an example. You have about 500 students, and have set up one conference bridge for each department, and have mapped one Gizmo account to each conference bridge. So you end up with a table something like this:
ConcordHSHistory (1-747-555-1001)
ConcordHSMath (1-747-555-1002)
ConcordHSForeignLanguage (1-747-555-1003)
ConcordHSScience(1-747-555-1004)
...So, to dial into History 302, you'd call ConcordHSHistory or 1-747-555-1001 and then dial extension 302 when you hear the greeting. Then you're dropped into a full duplex (all parties can talk) or listen only (only the teacher can talk) conversation. Simple.
Gizmo has a lot of other neat features including:
- Instant messaging: People can IM each other separately from the voice call
- Call recording: The instructor or students can record the conversation for future use
- Mapping: You can display caller locations on a live map, similar to Google Maps
Mostly I like Gizmo because it is very easy to install and use, works on Windows, Linux, and Mac computers, and it is based on open standards (which is why it can call directly into Asterisk systems, whereas other internet telephony services such as Skype are closed off, proprietary networks). At this point, it is the only free VoIP software I would recommend, but I will be updating this article periodically as new tools become available.
When to Use Your System
The goal of social distancing in a pandemic is to reduce or eliminate opportunities for influenza to spread. Public venues such as classrooms are especially hazardous, and will be closed promptly by public health authorities during an outbreak. The purpose of staging these systems for rapid use is to enable organizations to take their entire operation online on a moment's notice, without necessarily waiting to be told to do so. If you are prepared to host classes online, there is no reason to keep classrooms open if there is a risk to your students or employees.
Apart from the obvious benefit of limiting opportunities for the disease to spread, this will allow you to continue normal operations with little disruption. If you decide to implement this plan, you can inform all students and faculty that classes will continue, as usual, except online. By implementing this as a precautionary measure, you can demonstrate that you are prepared for this situation and, in the cases of schools, anticipate the concerns of parents who may keep their children home anyway. Being able to continue operations with some degree of normalcy will help to maintain morale and prevent panic.
Social Organizations and Businesses
People may be expected to stay at home or limit their contact with others for many weeks. People are social animals and most will have a difficult time doing nothing but watching TV or reading books for such a long time.
Electronic venues can play a role by enabling people to maintain social ties, both person-to-person and in groups, while they are hiding out. I am not suggesting that this will be fun or in any way a decent replacement for an evening at the local pub, but considering the alternative, it's better than staring at CNN.
Businesses and organizations that host social gatherings should be thinking about ways to re-create their events online. Business owners should be thinking about ways to create online venues, partly because most business will be closed down or deserted anyway, and they can provide their patrons with a surrogate place to gather, as well as entertainment to pass idle time. You can laugh at this suggestion, but after you've been holed up in your house for days with nothing to do but watch TV, you'll probably be thrilled to find some sort of distraction, even if it is playing drinking games with fellow barflies on a conference bridge. What else are you going to do besides be freaked out by the TV news?
What Your Users Will Need
Your users will need to have a home or laptop PC with a DSL or cable Internet connection. Gizmo will not work well over a dial-up Internet connection. The Gizmo client is free to download, and if you are only calling other Gizmo accounts, is free to use.
Users will get the best results if they buy a USB headset or handset to connect to their computer or laptop, although they can use the computer's built-in speakers and microphone (every caller should be trained to put their phone or Gizmo client on mute except when they are talking, this is to prevent background noise and feedback). A USB headset is not necessary if users will primarily be listening to a lecture and only speaking occasionally (as long as they remember to mute their lines when not speaking).
If you decide to offer local telephone connectivity via a VoIP service provider, such as Voxbone, users will also be able to call into sessions from any fixed line or mobile telephone. Again, I recommend steering as many people as possible toward Gizmo to avoid buying a lot of service from these providers. It costs $10 to $20 per month per phone line equivalent (per concurrent caller), so if you wanted to give 100 concurrent callers the option of dialing in via their regular phones, it will cost you $1,000 to $2,000 per month on top of your other costs, whereas allowing people to call in via Gizmo costs nothing on top of basic server rental and connectivity costs.
