In some situations, you might want unicast support in Access Grid because multicast is not available or impossible to implement, e.g., VPN. Fortunately, Access Grid comes with built-in unicast-to-multicast bridge support especially Access Grid 3. However, it is a kind of undocumented feature. I found a few tutorial how to run it. Actually, there are many possibility to run a bridge in Access Grid 3.

The most easiest way is to run a bridge on your host. This bridge will be available for all Access Grid over the world. You need to specify a name and a location for your bridge via options.

Bridge --name= --location=

Or on Windows:

C:\Python23\python.exe C:\Program Files\AGTk-3\bin\Bridge.py --qbexec="C:\Program Files\AGTk-3\bin\QuickBridge.exe" --name= --location=

Above commands will automatically register your bridge to the default registry specified at http://www.accessgrid.org/registry/peers.txt. Currently, it is pointed to nietzsche.mcs.anl.gov:8030. However, there are some cases where you are unable to access that host:port because of your firewall. In other words, you wish to use Access Grid in your intranet. So, you have to run an registry for your own environment as follow.

python /usr/lib/python2.3/site-packages/AccessGrid3/AccessGrid/Registry/RegistryPeer.py --peerListUrl=

And on Windows:

C:\Python23\python.exe C:\Python23\Lib\site-packages\AccessGrid3\AccessGrid\Registry\RegistryPeer.py --peerListUrl=

where peerlisturl must be substituted by an URL with hostname and port of itself. For example, the registry host, namely ag-registry has an IP address 10.4.9.240 so the content of this file should be as follow.

10.4.9.240:8030

However, RegistryPeer.py expected to find its hostname in that file. So you should have another local file with below content.

ag-registry:8030

In conclusion, you have 2 files. You have to put the first file with IP address on a web server so everyone in intranet are able to access its URL, says http://10.4.9.240/registry/peers.txt. The later one should be place locally, says C:\Program Files\AGTk-3\peers.txt or /etc/AccessGrid3_peers.txt.

python /usr/lib/python2.3/site-packages/AccessGrid3/AccessGrid/Registry/RegistryPeer.py --peerListUrl=/etc/AccessGrid3_peers.txt

Or on Windows:

C:\Python23\python.exe C:\Python23\Lib\site-packages\AccessGrid3\AccessGrid\Registry\RegistryPeer.py --peerListUrl="file:///c|/Program Files/AGTk-3/peers.txt"

To use above registry, you have to modify Config/preferences in user specific data path as follows.

bridgeRegistry = http://10.4.9.240/registry/peers.txt

Next step is to restart Venue Client to activate the change. You should see your bridge in menu.

Tags: access grid, grid, bridge