03/11/2003 1 Ulrich Schwenn (RZG) – H.323 Videoconferencing 03/11/2003 1 Budapest, RP-Training & Workshop May 2004 H.323 Video Conferencing H.323 Video Conferencing Dr. Ulrich Schwenn, Dr. Ulrich Schwenn, Kewin Kewin St St ö ö ckigt ckigt {schwenn|kfs}@rzg.mpg.de Multimedia & Videoconferencing Group http://www.rzg.mpg.de/vc Computing Center Garching (RZG), Max-Planck-Gesellschaft (MPG) & Max-Planck-Institut für Plasmaphysik (IPP) EFDA Remote Participation Training & Workshop KFKI Budapest, Hungary May 2004
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03/11/2003 1
Ulrich Schwenn (RZG) – H.323 Videoconferencing
03/11/2003 1Budapest, RP-Training & Workshop May 2004
H.323 Video ConferencingH.323 Video Conferencing
Dr. Ulrich Schwenn, Dr. Ulrich Schwenn, KewinKewin StStööckigtckigt{schwenn|kfs}@rzg.mpg.de
•• WhatWhat Else? Else? •• Future of H.323Future of H.323
AcknowledgementsAcknowledgements
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Psychology, Ergonomics & Acceptance of VC-Services
3. What is "Multimedia Conferencing"? (IMTC Definition)Multimedia conferencing revolutionizes vital, everyday tasks such as
corporate management, training and communication betweengeographically-dispersed teams. This technology enables interactive, live
sharing of audio, video and desktop applications during a conferencesession. Multiple users participating from geographically distant locationscan collaborate on an application and share visual information while they
discuss a project together. Internet voice and video and PSTN videoincrease productivity and reduce travel time and cost, while offering a personal mode of communication. Applications are wide-ranging and
include investor relations, telemedicine, distance learning, technical design reviews, and other collaborative activities.
http://www.imtc.org/faq/#3
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ITU ITU –– UmbrellaUmbrella standardsstandards
H.264
H.264
H.264
H.264
G.722
G.722 H.239
H.239
H.235
NEW or important:
H.264H.264 same video qualityat ½ bandwidthTandberg & Polycom(mostly proprietory)
H.235H.235 Encryption DES/AES(no problem for IPP,working with all Tandbergs)
EFDA Remote Participation Training & WorkshopKFKI Budapest, Hungary
May 2004
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Outline of talkOutline of talk
• ViDe• GDS – Global Dialing Scheme
– How does it work?– Who is responsible?– Dialing examples
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ViDeViDe
• ViDe stands for Video Development Initiative• Hosted at University of North Carolina at Chapel Hill
(UNC)• ViDe belongs to the Internet2 initiative• Was founded by several representatives of
universities and educational networks• ViDe wants to deploy digital audio and video in
research and higher education• Numerous workgroups doing “active” research in
different areas, e.g. data collaboration, streaming, etc.
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ViDeViDe
• Virtual network, based on the H.323 standard– Network consists of several zones (more about zones later)
• ViDe comprised several autonomously managed H.323 gatekeeper around the world– Management of IP traffic– Get “your personal videonumber (E.164)”– Allows interaction with MCU (multipoint conference units;
needed if more than 2 systems want to communicate with each other)
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GDS GDS –– Global Dialing SchemeGlobal Dialing Scheme• GDS is a numbering plan for videoconferencing
systems, MCU conferences, gateways and other audio/video communication related systems
• GDS is similar to the telephone numbering scheme– IAC (International access code): 00– CC (country code): e.g. 36 for Hungary, 49 for Germany,
etc.– OP (Organization prefix): e.g. 200 for KFKI, 893299 for
IPP Garching– EN (Endpoint number): e.g. 2011 for P. Giese, 6004 for U.
Schwenn– An E.164 number (~ GDS number) consist of
<IAC><CC><OP><EN>
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GDS GDS –– Global Dialing SchemeGlobal Dialing Scheme
• GDS uses a hierarchy of gatekeeper
• Each gatekeeper represents one zone– A Zone is a pool of
videoconferencing systems, belonging to one Organization prefix
– It does not matter, if videoconferencing systems are on the same network; they can be widespread
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GDS GDS –– Global Dialing SchemeGlobal Dialing Scheme
• Several research network provider, like NIIF, DFN, etc. host country gatekeeper who represent the country code (CC)
• Those CGKs are connected to the world gatekeeper, owned by the Welsh Video Network, University of Wales, Ireland
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GDS GDS –– Global Dialing SchemeGlobal Dialing Scheme
~ 1-2 multipoint / w - positivepositiveNetMeeting, VNC in regular use - positivepositive2 IP interrupts ((ISDNISDN backupbackup) ) 120 conferences (280h) in 2003120 conferences (280h) in 2003 -- positivepositive
DesktopsDesktops ~25 ViaVideo, 2 Tandberg 1000 - positivepositive> 10 connections / client / weekVNC in regular use - positivepositive
EFDA Remote Participation Training & WorkshopKFKI Budapest, Hungary
May 2004
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Outline of talkOutline of talk
• The Problem – A short introduction• GnuGK – The OpenSource solution
– Why GnuGK?– How does it work?– A few features
• ViDeNet & GDS• Authentication schemes• …
– Security aspects– Statistics
• Summary & Acknowledgement
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The problem The problem –– a short introductiona short introduction
• Complexity of media streams– Several udp and tcp streams, e.g.
• Q.931, H.245, H.225.0 are tcp (control) streams• Video and audio data are encapsulated in udp packets
– Amount of data per second• A vc connection with 512kbit/s send approx. 90 udp packets with an average
packet size of 750 bytes per second
• Dynamic Port allocation– H.323 uses a few fixed ports, e.g. 1719/tcp , 1720/tcp– Per connection approx. 6 to 8 ports needed– Ports are negotiated dynamically during the connection setup
• Used port range: > 210 & < 216 (1024-65535)• How do you open ports (on a firewall) if you don’t know them?
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The problem The problem –– a short introductiona short introduction
• “Blocked” communication or what happens if…– Setup (often) can pass firewall, but audio and video
data are blocked– Standard scenario: external (unprotected) client gets audio
and video, but internal (protected) system gets nothing
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GnuGK GnuGK –– The OpenSource solutionThe OpenSource solution
• Why GnuGK?– It’s free (GPL)– It runs on Linux…also free (Windows/Mac version also
available)– It’s a combination of a regular gatekeeper and a proxy– Fully H.323 v.4 compatible– 100% compatible to ViDeNet & GDS
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GnuGK GnuGK –– The OpenSource solutionThe OpenSource solution
• How does it works?– Videoconferencing system communicates only with the proxy– ALL data, tcp data (control channels, etc.) as well as audio
and video data (udp) are transmitted via the proxy
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……just a few features…just a few features…• ViDeNet & GDS
– GnuGK can be fully integrated into the existing ViDeNet & GDS (Global Dialing Scheme) structure → dialing of E.164 numbers rather than IPs
– E.g. Gatekeeper in Garching has Zone 0049893299 → it is easier to remember an E.164 number: 00498932996004 instead of 130.183.2.60
• Authentication schemes– Many different authentication methods available, e.g. H.350
(LDAP), mySQL authentication, Radius authentication (incl. billing)
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……just a few features…just a few features…
• Proxy can be fully/partial deactivated, simply by setting
• Port range (H.245, Q.931, T.120, RTP) can be limited– This limits the amount of concurrent calls– May cause problems with MCU conferences
• NATed endpoints are supported• Call queuing/forwarding• Load balancing
[Proxy]Enable=0
[Proxy]Enable=1
[Proxy]Enable=1InternalNetwork=10.10.2.0/24
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Security aspectsSecurity aspects
• Firewall “just” open for gatekeeper/proxy → all videoconferencing systems are protected by the firewall and can’t be hacked/attacked
• System is as secure as any other system on the public internet
• Everything you have to “protect” is the gatekeeper/proxy– Switch off all unnecessary services, e.g. www, ftp, ssh (from
outside)– Install all security fixes/patches
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Security aspectsSecurity aspects
• NOTICE: ALL SYSTEMS CAN BE HACKED/ATTACKED AS LONG AS THEY ARE CONNECTED TO A NETWORK/INTERNET/etc.
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Statistics (I)Statistics (I)• GnuGK is used for ALL videoconferences in IPP/RZG
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Some (Technical) ConclusionsSome (Technical) Conclusions• Desktops:Desktops: “ViaVideo” for Linux, MACs no topic, VRVS, AG unknown
Either stand-alone or MS solutions•• IMIM--Messenger:Messenger: The whole business is afraid of MS (mice & cat…tiger);
SIP is standard & supported by RadVisions MCUs now;
•• H.264:H.264: H.264 by Tandberg, Sony & Polycom, ITU in 06 / 2003High-Resolution Video Conferencing this year
•• Multipoint:Multipoint: MPG - MCU at DFNVC working since April 29, 2003NIIF - MCU working since April 29, 2004
H.323 will be the only VC Infrastructure H.323 will be the only VC Infrastructure commercially supported & generally applicable commercially supported & generally applicable
for several (>4) yearsfor several (>4) years
Future of H.323Future of H.323
Let’s use it!Let’s use it!
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Psychology, Ergonomics & Acceptance of VC-Services
Relative Importance of1 IP-Technics – Hardware, Networking, Firewalls2 Facilities – Audio, Video, Presentations / Applications3 User-System Interfaces – Media Control4 Interoperability between different rooms AND persons5 Acceptance of the whole system by users
is often mixed up, especially by scientists and even more byexperimentalists, tending to concentrate on tec-problems.
Due to our experience the order from a users point of view is(from most important psychological to technical necessities):
5 > 4 > 3 > 2 > 1 5 > 4 > 3 > 2 > 1 Video Video ConferencingConferencing isis a just a just anotheranother Service!Service!
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IPP Video Group:IPP Video Group: Paul Pflüger, Henning Soenke, Paul Pflüger, Henning Soenke, KewinKewin Stöckigt NZL Stöckigt NZL ½ Thomas von Weber, Wolfgang Harwardt, Andreas ½ Thomas von Weber, Wolfgang Harwardt, Andreas StareprawoStareprawo IPPIPP
Sybilla Sybilla BunneBunne, Hans Pfeiffenberger , Hans Pfeiffenberger AWIAWIHorst Wenzel et al. Horst Wenzel et al. VCCVCC
Gisela Gisela MaissMaiss, Jürgen Hornung et al. , Jürgen Hornung et al. DFNVCDFNVCKarl Karl BehlerBehler AUGAUG, , DirectorateDirectorate IPPIPP
StudentsStudents 2003: A. 2003: A. FlexederFlexeder, L , L MaronnaMaronna TUMTUMW. Steigemann, G. Neumann W. Steigemann, G. Neumann MPGMPG--GVGV
P. Giese, O. P. Giese, O. HemmingHemming, J. , J. HowHow, V. Schmidt , V. Schmidt EFDAEFDA
W.Bauer, A.W.Davis, N. Hahn, D. W.Bauer, A.W.Davis, N. Hahn, D. HeldnerHeldner, T. , T. KulaKula INDUSTRYINDUSTRYW. W. NatzerNatzer,, AA. . SeipelSeipel, U. Schmidt, J. , U. Schmidt, J. ThiermeyerThiermeyer
No WLAN YesSXGA Display XGAYes PC monitor No6-9 K€ Price 7-9 K€
NDA‘s from Polycom &Tandberg
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Fire-wall
Mbit Load Large MR
Small MR
Offices Large MR
Small MR
Offices Large MR
Small MR
Offices
UKAEA UK (Culham Lab) 200 Y Y Y None Y Y None Y Y None ?UKAEA UK (JET Facilities) 300 Y Y Y None Y Y None N N None Y
DRFC France 300 Y 10 10% typ50% max Y Y 10 N N None N N None Y
IPP Garching, Germany Y 600 <<100% N Y 2 Y Y 2 Y Y None NIPP Greifswald, Germany Y 500 ? N N None Y Y None Y Y None ?EFDA Garching Germany 37 Y 28 <10% N N None N N 5 N Y None YFZJ/IPP Germany 130 Y 622 ? Y Y 5 Y Y 5 Y Y None YFZK Germany 30 Y 155 ? N N None Y N None Y N None ?ENEA Frascati Italy 60 Y 16 <20% Y N 2 N N None Y N None NConsorzio RFX Italy 70 Y 8 <20% N Y 2 N N 1 N N None YIFP-CNR Italy 20 N 12.5 30% Y N 2 Y N None N N None YCIEMAT Spain 60 Y 100 10% N N None N Y None N Y None N
KFKI Hungary 18 Y 1000 10% typ50% max
N Y 5 N N 2 N N None Y
Tekes/HUT, Finland 17 Y 100 low N Y 5 N N None N N None YCRPP Switzerland 80 Y 40 ? N N ? N N None N N None n/aCFN Portugal 50 ? ? ? N N None N N ? N N None ?FOM The Netherlands 40 Y 1000 "acceptable" Y Y 2 N Y 2 N Y None YERM Belgium ? Y 10 ? N Y ? N N None N N None ?ULB Belgium 10 N 10 ? Y N None N N ? N N None ?ÖAW Innsbruck 10 N 100 ? N N None Y Y ? Y Y None ?ÖAW Wien 5 Y 100 ? N N 1 N N None N N None n/aAlfvén Lab Sweden ? N 100 "acceptable" N N 5 N N None N N None n/aRisø Nat. Lab Denmark 10 Y 100 ? N N None Y Y ? N N None ?IFIN Romania ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Fusion Staff
Network VRVS/Mbone H.323 H.320 Phone backup in MR
300
Laboratory
8 <10%
EFDA EFDA --Teleconferencing 2003/4 Teleconferencing 2003/4 Approximate status 2004Approximate status 2004 “Old” Labs“Old” Labs
>25>2533 1010
22 22
22 22
22
11
22
1111
2?2?
11
NowNow??
11 66
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