[AG-TECH] One-page summary of AG port usage -- please help us complete it

Mon Feb 13 13:51:24 CST 2006

Hi,

It is worth noting that so long as the addresses are different for each room, there should be no problem if all rooms use the same port numbers.  However the problem is that with dynamic allocation, you cannot be sure that you will get a different address accross different venue servers.  The short-term solution to this is for each person running a venue server to make sure that the multicast address range is different from that of any other venue server.  The long-term solution is to look at some sort of venue server talking where by the venue servers talk (maybe using a fixed multicast address) and annouce when they are using an address, so that the other servers don't use it.  If multicast is not felt to be reliable enough for this, perhaps some sort of DNS-type structure can be put in place for this (or even use DNS if possible, registering multicast addresses dynamically to venue related host names).

Note that the current solution could result in some fairly heavy bandwidth if lots of people happen to be allocated the same address for different venues, even if the ports are different.  You tend to join a multicast address, and will therefore get all the traffic for that address arriving at your computer regardless of the port being used, so you may find your bandwidth all used up if there are lots of big meetings in this situation.

Andrew :)
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-----Original Message-----
From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On Behalf Of Nagykaldi, Zsolt F. (HSC)
Sent: 13 February 2006 18:36
To: 'Ivan R. Judson'; 'R. P. Channing ["Rick"] Rodgers'; 'ag-tech at mcs.anl.gov'; 'michael.daw at manchester.ac.uk'
Cc: 'bernholdtde at ornl.gov'; 'jsummers at bachman.cs.ou.edu'; 'terrazas at labmed2.ucsf.edu'
Subject: RE: [AG-TECH] One-page summary of AG port usage -- please help us complete it

This is exactly why the AG community must agree on FIXED port numbers (can I suggest a port registry for venues/rooms?? e.g. NCSA Titan will also use these ports ... for video and audio). Which (along with the URLs of individual rooms) should not change when servers are rebooted, serviced, etc. This would make it possible to write simple batch files or apps that could pull up individual rooms with set preferences (unicast, multicast, etc) automatically with a click of a button. This would be extremely important for regular meetings with individual "lay" participants.

Zsolt

_ _ _

Zsolt Nagykaldi, PhD
Research Associate, Clinical IT Specialist
University Of Oklahoma Health Sciences Center
Department Of Family And Preventive Medicine
Oklahoma Center For Family Medicine Research

900 NE 10th Street
Oklahoma City, OK 73104
Phone: (405) 271-8000 Ext.:1-32212
Fax:     (405) 271-1682

From: owner-ag-tech at mcs.anl.gov on behalf of Ivan R. Judson
Sent: Mon 2/13/2006 11:41 AM
To: 'R. P. Channing ["Rick"] Rodgers'; ag-tech at mcs.anl.gov; michael.daw at manchester.ac.uk
Cc: bernholdtde at ornl.gov; jsummers at bachman.cs.ou.edu; terrazas at labmed2.ucsf.edu
Subject: RE: [AG-TECH] One-page summary of AG port usage -- please help us complete it

I think what you're hearing is unwillingness for anyone to commit to a wrong
answer.

>From memory, the ports for vic, rat, and the rest of the tools are allocated
by the venue server. It can be a static allocation configured by the
provider or a dynamic allocation (I think the default).

Given this configurability, it's impossible to state exactly what ports the
media tools will or won't use.

Sorry for the complicated answer.

--Ivan

> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
> Behalf Of R. P. Channing ["Rick"] Rodgers
> Sent: Monday, February 13, 2006 11:36 AM
> To: rodgers at nlm.nih.gov; ag-tech at mcs.anl.gov; michael.daw at manchester.ac.uk
> Cc: bernholdtde at ornl.gov; jsummers at bachman.cs.ou.edu;
> terrazas at labmed2.ucsf.edu
> Subject: RE: [AG-TECH] One-page summary of AG port usage -- please help us
> complete it
>
> Michael,
>
> Thanks, I agree that AG Central would be an excellent development resource
> and then final home for our summary of AG port usage.  We certainly need
> help completing it.  The biggest gap right now is port ranges for vic and
> rat.
> I just *know* that folks working with the code for these applications more
> actively than we do could produce these numbers in a few minutes.
>
> In browsing around in the AG Central forums, it appears that they have
> only
> received light traffic thus far, not that that should stop us from helping
> to
> kick-start the community there.  It's not clear which forums would be
> optimal
> for our purposes -- I suppose "AG Toolkit/General"?  So I'm taking your
> advice,
> reattaching our two documents here, and also posting my original message
> to
> "AG Toolkit/General" on the forum at http://agcentral.org as wel.
>
> CORRECTION: just tried to do the above, and got completely wedged -- not
> clear that I have permissions to post to the forum, even though I'm
> registered.
> Then my web client got completely stuck.  Will try again later, sigh...
>
> Cheers, Rick Rodgers
>
> > From: "Michael Daw" <michael.daw at manchester.ac.uk>
> > Subject: RE: [AG-TECH] One-page summary of AG port usage -- please help
> us
> complete it
> > Date: Mon, 13 Feb 2006 09:43:55 +0000
> >
> > Great work guys! This is going to be good.
> >
> > But, can I suggest using http://agcentral.org for this? If the document
> is
> discussed and refined in a forum, it will be easy to find. Once it's
> ready, it
> can be posted to the help center. Because most of us still aren't
> completely
> used to using agcentral, you can always post frequently to ag-tech too
> with
> pointers.
> >
> >
> > > -----Original Message-----
> > > From: owner-ag-tech at mcs.anl.gov
> > > [mailto:owner-ag-tech at mcs.anl.gov] On Behalf Of R. P.
> > > Channing ["Rick"] Rodgers
> > > Sent: 10 February 2006 20:21
> > > To: ag-tech at mcs.anl.gov
> > > Cc: rodgers at nlm.nih.gov; bernholdtde at ornl.gov;
> > > jsummers at bachman.cs.ou.edu; terrazas at labmed2.ucsf.edu
> > > Subject: [AG-TECH] One-page summary of AG port usage --
> > > please help us complete it
> > >
> > > Dear AG Colleagues,
> > >
> > > I now realize that the work I started last December, trying
> > > to create a
> > > one-page summary of AG port usage (based on the commendable
> > > document created by
> > > Javier Gomez Alonso of the Access Grid Support Centre at the
> > > University
> > > of Manchester) is not easily locatable in the list archives.
> > > I resend it,
> > > attached, along with the Excel version that David E.
> > > Bernholdt of ORNL kindly
> > > created.  As I said earlier, all of these documents are missing some
> > > key information, such as the port ranges used by vic and rat.
> > >  I send this out
> > > again in the hope that another AG colleague will pick it up
> > > and complete it.
> > > We all really need to have something like this, and i would
> > > hope that eventually
> > > it would end up on the AG web site(s), and be maintained to
> > > reflect any
> > > coding changes/additions made to AG software.
> > >
> > > Best Regards, Rick Rodgers
> > >
> > > --------------------------------------------------------------
> > > ------------------
> > > R. P. C. Rodgers, M.D. * rodgers at nlm.nih.gov * (301)435-3267
> > > (voice, fax)
> > > OHPCC, LHNCBC, U.S. National Library of Medicine, NIH
> > > Bldg 38, Rm. B1N-30F2, 8600 Rockville Pike, Bethesda MD 20894 USA
> > > http://lhc.nlm.nih.gov/staff/rodgers/rodgers.html
> > >
> > >
> > >
> >
>
> --------------------------------------------------------------------------
> ------
> R. P. C. Rodgers, M.D. * rodgers at nlm.nih.gov * (301)435-3267 (voice, fax)
> OHPCC, LHNCBC, U.S. National Library of Medicine, NIH
> Bldg 38, Rm. B1N-30F2, 8600 Rockville Pike, Bethesda MD 20894 USA
> http://lhc.nlm.nih.gov/staff/rodgers/rodgers.html

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