[AG-TECH] Potential Authentication Proxy "work around" for getting Unicast Bridge Listing

Jason Bell j.bell at cqu.edu.au
Fri Feb 22 06:48:48 CST 2008

G'day Ben

Thanks for your email.

In regards to why this work around "might" work on some authenticating
proxies, is because some proxies are set to restrict certain ports, such
as port 80 (http), and the likes, but not all ports.

Therefore, some authenticating proxies may not restrict all ports which
is why unicast bridging works.  It may also have to do with unicast
bridging possibly using udp as well.  I have seen this work for a site
or two.  Fortunately, I don't have the restrictions like some others AG
sites, therefore, I cannot be sure why it works for some sites, thought
I hope it may resolves some issues for other sites.

Of course, I would be happy to received any feedback and comments.

I hope this clarifies some things.


-----Original Message-----
From: Ben Green [mailto:ben.green at manchester.ac.uk] 
Sent: Friday, 22 February 2008 8:30 PM
To: Jason Bell; ag-tech at mcs.anl.gov
Subject: RE: [AG-TECH] Potential Authentication Proxy "work around" for
getting Unicast Bridge Listing

Hi Jason,

Thanks for the info.

I have one question though. If an AG3 client has to pass through an
authenticating proxy, how would it connect to a meeting in the first
place, regardless of whether or not it retrieves a list of bridges?

I'm asking on behalf of a user who cannot connect to the venue server
'apparently' due to the fact that you cannot specify a proxy
username/password within the network preferences of the client. This
same user claims to be able to specify such settings within other
applications that bypass his proxy OK.

Cheers, Ben.

Ben Green
Access Grid Support Centre
Research Computing Services
University of Manchester
Room G49-H
Kilburn Building
Oxford Road
M13 9PL
tel - 0161 306 6621
email - ben.green at manchester.ac.uk
web - www.agsc.ja.net


-----Original Message-----
From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
Behalf Of Jason Bell
Sent: 22 February 2008 06:02
To: accessgrid-l at clix.aarnet.edu.au; ag-tech at mcs.anl.gov;
AG-Tech-NZ at googlegroups.com
Subject: [AG-TECH] Potential Authentication Proxy "work around" for
getting Unicast Bridge Listing


This may interest some of those who have problems obtaining a unicast
bridge listing due to an authenticated proxy issue.

I have posted a "Potential Authentication Proxy "work around" for
getting Unicast Bridge Listing" up on the AG website which can be found
at http://www.accessgrid.org/node/1086.

I hope some of you find this useful.

Note: comments and suggestion are always welcomed to improve the


Jason Bell, B.I.T. (Honours)

High Performance Computing Support Officer, Network Engineer Information
Technology Division Central Queensland University

E-mail : j.bell at cqu.edu.au
Work   : 07 4930 9229
Mobile : 0409 630897
Patience is a virtue.

But if I wanted Patience,
I would have become a Doctor.

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