This post continues our 20 Day Challenge to understand the technical aspects of videoconferencing.
Today we examine the role of gatekeepers in an H.323 video conference environment. Some people view gatekeepers as an essential part of video conferencing; others view them as an annoyance and hindrance. Here’s our collective view of how they work in the K12 curriculum videoconferencing environment.
Why Gatekeepers Are a Pain
For those used to the “old school” method of dialing a straight IP address to VC with another school, gatekeepers can be challenging and frustrating. Here are some of the ways that gatekeepers can cause problems:
- Older gatekeepers can strip off the extension you’re trying to dial. If you are trying to dial out to someone with one of the firewall traversal systems – an alias and an IP address, sometimes the gatekeeper doesn’t know what to do with the extension. So it strips it off and your call doesn’t work. This seems to happen more often with older gatekeepers.
- Even if your gatekeeper supports the extension dialing, you can still have problems dialing other schools that are using a gatekeeper. It may not work, or you may not be aware of the method required to call through that other type of gatekeeper.
- The vendors will tell you to neighbor your gatekeeper with the other school’s gatekeeper, but that is problematic as well. What if you’re participating in Read Around the Planet and have 20 other schools to connect to? What a pain to neighbor to all of their gatekeepers! In addition, the process to neighbor your gatekeeper to another gatekeeper is not easy or intuitive. You’ll probably have to open a trouble ticket with your vendor just to figure out how!
Why Gatekeepers are Awesome
That said, there are some very good reasons to use a gatekeeper!
- If your network has many videoconference units that connect to the Internet via DHCP, the gatekeeper can assist with dialing. It keeps track of which units are registered to the gatekeeper by serial number, and assigns the same alias to it, no matter where it is on the network. This makes dialing within your network very easy. Even with dialing from outside the network, the alias is consistent which makes it easy for the other site to dial no matter where the unit is inside the network.
- If you have a limited number of public IP addresses and cannot assign one to each videoconference system, the gatekeeper can provide the public IP address, while the rest of the systems are using an alias registered with the gatekeeper.
Gatekeepers and the Global Dialing Scheme
If your school is on Internet2, you may have support to get your videoconference systems on the Global Dialing Scheme (GDS). Basically, this means your gatekeeper is neighbored into a gatekeeper tree structure used around the world for dialing within the education community. For Berrien RESA, the advantage is the ease with which we can call schools in the UK who are on the JANET network. We have also used this for dialing some schools in Minnesota and Pennsylvania. Unfortunately GDS is used more in higher education than K12. If we were able to adopt it more broadly, it would solve many of the dialing problems we keep addressing in this series.
If you want to get on GDS, here’s what you need to do:
- First check with the Internet2 contacts in your state/area. It’s likely that you will neighbor your gatekeeper to a state gatekeeper.
- If there isn’t a strong K12 support for Internet2 in your state, you may need to neighbor your gatekeeper to the Internet2 Commons gatekeeper.
- If you need help neighboring your gatekeeper, you’ll need the IP address of the gatekeeper you’re neighboring with. Then call your VC tech support and they should be able to help you.
- Which side do you take for gatekeepers? Essential or a hindrance? Why? Please share!
- Did we miss anything important in the discussion of gatekeepers? Please add any additional points that shed light on these issues.
Team-written by Janine Lim, Shane Howard, and Roxanne Glaser with input from Lori Colwill. The opinions expressed in these posts are based on our collective video conference experience connecting classes across multiple networks to connect them to zoos, museums, experts and other classes during the past 10 years. This series of posts reflects our usage and understanding, not that of any vendor or manufacturer. No one is paying us to write these. We are just sharing what we have learned.