1. 31 May 2006 VoIP and Conferencing Facilities for OCCASION
Voice and Video Conferencing Facilities for the
Silk/OCCASION Project
Peter T. Kirstein, 31 May 2006
1. The Background
There are nine remote sites (in the Caucasus and Central Asia) and three European
ones in the Silk/OCCASION project. At each remote site there are currently two
Cisco 7960 telephones. Shortly there will be also a Tandberg H.323 conferencing set-
up. At each remote site there is a National Research and Education Network (NREN);
attached to the NREN there can be additional similar hardware end-systems and also
potentially software-based ones. Currently, during the present phase of the project
called Silk-1, there is a VSAT satellite link between the remote sites and the DESY
hub; the speed of the international communications is variable - the bandwidth is
currently asymmetric, with 384/1024 Kbps available at each remote site – though the
1024 Kbps is a shared Westà East channel whose B/w can be varied. The VSAT hub
ends at a Cisco GSR, while the remote sites have connection to a 7200 Cisco router,
which is, in turn, attached to the German NREN. We are in the middle of a tender
operation for Silk-2. This envisages somewhat higher bandwidths, but roughly the
same termination of the communications.
In Silk-1, at the Western sites, the end-stations are connected to LANs, which have an
access speed of at least 100 Mbps. These on LANs connected to Cisco routers which
are 7200s or GSRs. Their connections to the GEANT WAN are at least 1 Gbps – and
usually more. There are some hardware Polycom or Tandberg H .323 boxes, some
Cisco 7960 telephones, and some soft-wired systems.
While the communications in Silk-2 may be partially by fibre to the remote NRENs,
we can assume that the bandwidth will not be reduced – and that all sites will be
connected via the Silk-2 network to GEANT or directly to DESY.
DESY has a substantial VoIP park now, and will be putting in several thousand units.
These are mainly for normal point-point telephony. It is possible to access a H.323
MCU through the German DFN NREN. The UCL deplo yment is on a much smaller
scale – though it also has access to a H.323 MCU through the UK UKERNA NREN.
During the past four years, we have held regular Silk Exco meetings. These have
involved some 6-8 Western partners and 2-3 from the Silk countries. The mechanism
has been to use the Cisco MeetingPlace, operated at Cisco, to run voice conferences
with local dial- in. UCL has run a CallManager server, and has organised dial-out from
it into MeetingPlace over the PSTN; three telephone lines were kept for this purpose.
Silk NREN members of Exco then dialled over the Silk-1 network to a particular
extension on the UCL CallManager – which did automatic dial-out to MeetingPlace.
This mechanism does not scale to a significant number of remote users. DESY also
ran a CallManager. Simple VoIP calls between the Silk NRENs and the Silk NOC at
DESY went over the DESY CallManager. They implemented password-controlled
Call-out to the general PSTN and some billing. This has worked well. Since DESY
used Skinny and UCL SIP, with early versions of the software, there was no
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2. 31 May 2006 VoIP and Conferencing Facilities for OCCASION
compatibility between the systems; the end-systems had to run either Skinny or SIP –
and could use only one of the CallManagers. Over the last few months UCL upgraded
to CallManager-4, and intended to at least interwork between its CallManager-4 and
that of DESY. This would allow any of the end-systems to interwork. Unfortunately
we ran into a firewall bug at DESY; it has taken several months to cure it, and in the
meantime, the impasse remains.
2. The Requirement
Over the next couple of years, we want to introduce the Silk community to a much
more significant use of VoIP and Conferencing. Ideally some of this would even work
over IPv6. We would like to have enough equipment so that at least some of the VoIP
phones can do video-telephony, and can be deployed more widely than in the NREN
premises. We have provided one hardware H.323 Tandberg end-station at each
NREN; each NREN is commissioning a conference room to have serious conference-
room based conferencing. We would like to deploy hardware video-telephones at a
few points on each NREN, but allow some of the users to employ also software end-
systems for VoIP and H.323 conferencing. It is probable that many of the potential
users are not very sophisticated, and might find it very difficult to manage software
telephones or H.323 systems.
Initially most of the usage will be within the OCCASION partners (i.e. the Silk
NRENs, UCL, DESY and RUG). However, we would like to be able to have
substantial sized conference calls – with up to 15 simultaneous users. This greatly
exceeds the hardware limit of 4 in the 7960. We would also like to become
independent of Cisco for managing such conferences. For this reason we would like to
run a MCU for such conferences – preferably one that can manage both H.323 and
VoIP. We expect to have to do a considerable amount of experimentation, while
DESY runs this activity from their communications department. As a result there are
considerable delays if we try to do new things at DESY.
As a result, our requirement is that there be a complete system at UCL, which is used
for all the experimental work and trouble shooting; this system would be used also for
any advanced services that have not been standardised in DESY services. There
should be a parallel production system at DESY, which installs the services that have
been debugged at UCL. Because we may be using a later version of the software at
UCL, the transition from one to the other may be slow in practice.
3. Equipment Available from Cisco
One part of this paper is concerned with what might be available from Cisco to
supplement what the partners have now, and what they might need. Here we must
consider end-stations, servers and multiplexing units. Each will be considered in turn.
3.1. End-stations
Clearly we need more discussion as to the exact models of end-stations that we should
be considering. I give some costs of single systems from a re-seller, to give examples
of the orders of magnitude that we are considering. As far as I can see there are only
several versions of telephone – sum with video capability:
The 7970 provides an integrated but simple display for transactions as well as voice
(£395). It can be combined with a laptop to provide a complete videophone system at
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3. 31 May 2006 VoIP and Conferencing Facilities for OCCASION
low cost. The cost of the software and camera together cost about £100. The
combined system is called VT Advantage.
The 7985 is a complete system with camera and display. It costs about £1575.
3.2. Systems Configuration
When we look at a complete system, this is illustrated in Fig. 1 below:
Video Unified VT
Endpoints Advantage
H.323/SIP
CallManager
5.X
GK
MeetingPlace IP
MP Audio Server- Gateway
PSTN or IP
MP API
H.323
IP Voice Link (RTP G.711)
MP MP Video
API
Scheduler
MCS Server
MP Web 5.4 IPVC MCU 5.0
MP Web
MP Video 5.4 • H.323/SIP and SCCP Ports
MP Outlook (Optional)
MP Voice • MP unique Service Prefix
MP Video Defined
•i.e. 65 + MP ID
Figure 1 Cisco Unified MeetingPlace Video with H.323 and Cisco Video Telephony Architecture
Here we will ignore for now the end-points. They have been discussed already in
Section 3.1. For our purposes the following exist:
• MCS Server
• Scheduler
• IPC MC 5.0
• MP Audio Server
• MP Video Scheduler
• MP Gateway
• GK
The MCS Server comes in various sizes.
The IPVC MCU does the multiplexing ; it comes in various models and sizes.
Probably the IPVC 3515 would be adequate for most purposes ; this allows neither
Basic Rate nor Primary Rate access. It would be helpful in include a 3522 Basic Rate
access gateway, to allow people to come in when they are not at their home place. We
could use either the MCU12 or the MCU24. The MCU12 allows 24 audio ports to be
transcoded, 12 video ports, and encryption. Both H.263 and H.264 are supported. For
signalling, H.323, SIP and SCCP are supported. The MCU24 has twice the capacity.
For the larger IPVC3545, there are both video and audio cards ; but I do not think we
need this.
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4. 31 May 2006 VoIP and Conferencing Facilities for OCCASION
We clearly need a Cisco MeetingPlace MP ; this provides all the scheduling and
synchronisation. We would clearly want the MP5.4.
We need the Call Manager, running Release 5.
One needs an IP-IP combined with a GK Gatekeeper. This would be a 2600 router for
QoS and Security, together with the 3725 for address resolution, user autorisation,
accounting and zone bandwidth management.
4. Proposed Configuration
4.1. Introduction
It is necessary to consider what we need to have at the end-stations, the Silk NREN
nodes, UCL and DESY. Each will be considered separately. With the present
equipment available from Cisco, it will be possible to do IPv6 work only with
software versions. Any equipment needed for this activity will be provided by the
OCCASION project – unless Cisco indeed decides to make such products. As far as I
can see this could only occur at a later stage – not earlier than 2007.
At least for this draft, I will assume that UCL will do all the experimentation, and
hence any of the Servers from Section 3.2 would come to UCL. DESY may put in
equipment for its own larger-scale deployment; hence it is expected that most of the
MCUs and similar equipment can be either obtained by DESY from using ESNET or
DFN equipment or will be purchased for DESY services.
UCL will put in the latest software releases that are advised; currently this will be v5
for any CallManager. DESY will put in software releases more slowly – because of
their need to run uninterrupted services.
4.2. End-stations
We expect that many of the Silk NRENs will put in telephones, desktop systems and
conference rooms. Cisco has already provided two 7960 telephones at each Silk site,
and several for UCL. I think that this has been a donation of about 24 telephones.
NATO has provided a Tanberg room videoconferencing system for each Silk site, and
the other three sites all have Tanbergs or Polycoms.
I would propose that Cisco considers whether it could make the following donations:
30 x 7970 telephones
30 kits to allow the 7970 telephones to become VT Advantage systems
6 x 7985 personal conferencing sytems
Any further systems should be purchased. Here it should be noted that some of this
type of equipment will be purchased as part of the Telephony and Conferencing being
taught under the Cisco Academies effort. A small number of these, probably two,
would go to each of the Western partners to ensure that they have compatible
equipment.
4.3. UCL Node
At the UCL node, we would need the following:
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5. 31 May 2006 VoIP and Conferencing Facilities for OCCASION
• Our existing Call Manager upgraded to run Release 5
• A PSTN gateway. Here we may be able to use our existing 3640, upgraded
with the latest software to provide Gatekeeping and QoS. This might require a
new box.
• An MCU. Here we would want a 3515-MCU12
• A Meeting Place Server. I am not clear whether this is a Media Convergence
Server (7800) or an Integrated Communications System (7750). This might be
an expensive item, but I cannot tell.
For the time being, all the QoS would be done at UCL and the call would be routed
directly from the end sites to UCL.
4.4. DESY Node
It would seem that at first we can run all the servers at UCL – on the assumption that
there is no QoS problem between UCL and DESY. It would probably be best to run a
unified Call Manager at both sites, in view of the operational role of VoIP in Silk
network management from DESY. It needs much more discussion which of these
servers will be needed eventually at DESY, and what they would expect to purchase
from their own resources. Since they will be a serious service provider, I suspect that
there is little point in their having the minimal equipment proposed here.
5. Making a System Work
Our experience over the last year has been that it has been very difficult to introduce
new services into an operational service system. Moreover, there has been slow
progress also in the NRENs due to the lack of effort in the NRENs. I propose to
request, and promise to Cisco, that if we get such donations, UCL and DESY will
provide half a person, and each of the NRENs provide a quarter of a person, for at
least a year. I propose also that three Silk NRENs provide somewhat more than the
above, since they would be part of any pilot systems.
I would expect that in addition to making the Cisco end-systems work, both UCL and
the Silk NRENs will introduce other end systems – particularly software based, PC-
based, conferencing systems.
There will be considerable work in many areas. First it will be necessary to configure
all the servers; this can be expected to require considerable work – and help from
Cisco. Moreover, it will require additional configuration on the communications
system; this was an effort which was envisaged in the original OCCASION proposal
as justifying some of the additional manpower at DESY. Finally, it will be essential to
have assistance at the Silk NREN sites both to participate in the experiments, and to
assist the eventual users.
6. Conclusions
This note has indicated how we propose to introduce the Silk sites to work with audio
and video conferencing. At this time I do not know the extent of a donation proposed
in the above. It is clearly that it would be invaluable in bringing the Silk countries into
the modern era of computer-based communications. The Public Relations and
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6. 31 May 2006 VoIP and Conferencing Facilities for OCCASION
Publicity payback would be considerable.The payoff to Cisco, when this is combined
with a training programme should not be underestimated.
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