[AG-TECH] Bridge server

[Andrew A Rowley]

Hi,

We currently restart our bridge server overnight to make sure that it is working each morning.  Unfortunately, this means that the bridges for a venue change port numbers every day.  It would be really useful if the bridge server stored the port numbers used for each venue in a file as the bridge is started, and then reuses these if possible on the next run of the bridge server.  This would mean that people may not need to open a whole range of ports just to use one venue, and I don't need to add a section in my bridge config for every venue (there are quite a few).

Even better than this would be to use something like a static bridge (see http://www.agsc.ja.net/services/staticbridge.php) which uses a fixed 4 ports regardless of the number of users or venues (although it does require each user to tell it where they want to send their traffic to). 

Andrew :)

============================================
Access Grid Support Centre,
RSS Group,
Manchester Computing,
Kilburn Building,
University of Manchester,
Oxford Road,
Manchester, 
M13 9PL, 
UK
Tel: +44(0)161-275 0685
Email: Andrew.Rowley at manchester.ac.uk 

> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
> Behalf Of Thomas D. Uram
> Sent: 24 April 2006 17:41
> To: Todd Zimmerman
> Cc: ag-tech at mcs.anl.gov
> Subject: Re: [AG-TECH] Bridge server
> 
>  > Given the importance/need for many of us to statically assign bridge
> ports,
> will this functionality
>  > be available in AG3?
> 
> Can you elaborate this point more?  What is currently in AG3 is this:
> 
> - A Bridge can be run with a particular port range specified.  The person
> running the
> bridge will have to ensure that these ports are open for udp through their
> firewall.
> 
> - A user will see which bridges are available, and can view the hostname
> and port
> range used by each.  The user can then decide which bridges to use, and
> pass
> this information to a network
> admin to open ports accordingly.
> 
> Questions this leaves open:
> 
> - What should the default port range for a bridge be?  How about 50000-
> 50200?  This
> would ensure that bridges will, by default, all use the same (relatively)
> narrow port range.
> 
> - Is this sufficient for your local networking needs?  There may be
> something
> additional
> implied by 'statically assign bridge ports', and I'd like it to be
> explicit so
> I can address it.
> 
> Tom
> 
> 
> 
> On 4/19/06 11:44 AM, Todd Zimmerman wrote:
> > Agreed.  We've been bridging our entire venueserver for years.  We only
> run into issues when we
> > overlap venueserver and venue configs.
> >
> > Given the importance/need for many of us to statically assign bridge
> ports, will this functionality
> > be available in AG3?
> >
> > Todd
> >
> > Thomas D. Uram wrote:
> >> Bridging an entire venue server is supported just fine in my
> experience.
> >> There may be problems if the config specifies an overlapping set by,
> >> say, specifying a venue server and individual venues on that server;
> >> these should be regarded as mutually exclusive options and, I think,
> >> in most practical situations, they are.
> >>
> >> Tom
> >>
> >>
> >> On 4/19/06 9:33 AM, Michael Braitmaier wrote:
> >>> Jeremy Mann schrieb:
> >>>
> >>>> So basically I have to manually bridge each room. In my config file I
> >>>> tried to set the entire VenueServer to only use a range of ports,
> then I
> >>>> entered ports for the rooms I wanted to configure statically. But I
> >>>> still
> >>>> came across that "Address already in use" problem.
> >>>>
> >>>> For example, I have the VenueServer set to 5000-5200 and 4 Venues to
> >>>> 5202
> >>>> on up.
> >>>>
> >>>>
> >>> I don't specifiy the ports for the venue server overall. Beside I
> >>> think bridging a whole venue server is not that well supported.
> >>> You have to specify the ports for each venue seperately. If you refer
> >>> to the ports of the VenueServer itself, these are configured through
> >>> the VenueServer
> >>> configuration. As fas I know through the VenueServer.cfg file, but I
> >>> didn't succeed in configuring it yet.
> >>>
> >>> Michael
> >>>
> >>>> Michael Braitmaier said:
> >>>>
> >>>>
> >>>>> I am doing basically the same. I restrict the range of the ports for
> >>>>> unicast for a specific venue.
> >>>>>
> >>>>> Config-File example:
> >>>>>
> >>>>> [https://rusagvideo.rus.uni-
> stuttgart.de:8000/Venues/000001026deebc1400c0006c00230006555]
> >>>>>
> >>>>> type=Venue
> >>>>> portMin=50096
> >>>>> portMax=50099
> >>>>>
> >>>>> One of the problems rising with this configuration method is that
> >>>>> normally AG selects ports on a random
> >>>>> pattern put of the range you specified in the config file.
> >>>>> Ports for rat and vic are allocated sequentially.
> >>>>> So first rat gets assigned 50096 for example.
> >>>>> When the port for vic should  be determined, it can happen due to
> the
> >>>>> nature of the random allocation
> >>>>> that for vic also 50096 is initially selected. This of course leads
> >>>>> to a
> >>>>> "Address already in use" error.
> >>>>> I avoided the problem by patching the AccessGrid files responsible
> for
> >>>>> port allocation to keep a list
> >>>>> of ports which are in use and have the allocation algorithm first
> check
> >>>>> if a port the algorithm wants to allocate
> >>>>> isn't in use yet.
> >>>>> Otherwise you have to restart the bridge server until you don't get
> the
> >>>>> "address already in use" error to be sure you really have
> >>>>> video and audio correctly bridged.
> >>>>>
> >>>>> Michael
> >>>>>
> >>>>>
> >>>>> Jeremy Mann schrieb:
> >>>>>
> >>>>>
> >>>>>> Thomas D. Uram said:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>> Which version of AG software are you using for BridgeServer and
> >>>>>>> VenueServer?
> >>>>>>> Can you post your full bridge cfg file?
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>> AG 2.4. Attached is the config file. Worth noted is that I no
> >>>>>> longer get
> >>>>>> those python errors, however, now when I start it, several of the
> >>>>>> venues
> >>>>>> aren't bridged because the bridgeserver says the address is already
> in
> >>>>>> use
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>> --
> >>>>> ------------------
> >>>>> Dipl.-Inf. Michael Braitmaier
> >>>>> HLRS - Visualization / Video Conferencing
> >>>>> University of Stuttgart
> >>>>> Germany
> >>>>> Phone: ++49 711 685 5996
> >>>>> Fax  : ++49 711 682 357
> >>>>> Website: http://www.hlrs.de/people/braitmaier/
> >>>>>
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>
> >
> >
>