Cascading servers
Consists of using computational resources of more than a MCU to increase the total of terminals of a conference
Reasons for cascade– Limit of depleted terminals– Computational resources depleted
(processing, memory) – Local bandwidth limitation – Local of administration needs
This example totalizes 42 possible connections
As balancing does not exist, is not possible, for example, more than 10 terminals connected to MCU 1
Cascade – without managing
Only one flow between MCUs
Increased capacity of each room
Connections to any room can be made in any MCU.
Cascade – without managing
Cascade – with managing
All the terminals connect in MC
MC provides a load balancing
MC manage all the terminals and conferences
Cascade – with managing
Only one flow of traffic between MC and MP
In this example, there are 45 connections in total.
Cascading
Multipoint Controller (MC):– it is responsible for control functions in a multipoint
conference. – it is responsible for setting of capacities with each
terminal that it desires to participate of the conference.
– it determines the selected ways of operation for the conference, that can be common for each participant of the conference or alternatively different for some terminals
Cascading
Multipoint Processor (MP):– receive signals from audio, video and data from the
participants of a centered or hybrid conference and makes a mixing or switching for each signal, returning the signal processed to the terminals.
– To the data signals, a MP will have to be able to act as a MCS not leaf or as a main MCS
Zone
The collection of all terminals, gateways, and multipoint control units managed by a single H.323 gatekeeper.
Gatekeeper provides control service of calls for the all H.323 terminals in the zone
Zona
Comparatively, a H.323 zone is similar to an autonomous system in the Internet: a single or a group of networks that is controlled by a common network administrator.
Inside the same Autonomous System, diverse H.323 zones can coexist, each one managed by gatekeeper different.
A H.323 net can be formed by several zones and and its gatekeepers
Zona
Register in the zone can be made of dynamic or manual form
IP addresses can be banished (blocked) of a zone
Zone – registration in gatekeeper (Cisco 3510)
< GK: 0001:33:31 Gatekeeper Request from ip 200.132.0.118:32829 [562602] > < GK: 0001:33:31 New message sent ->Gatekeeper Confirm to endpoint: [562603] >< GK: 0001:33:31 clearing registration number 19 [562603] > < GK: 0001:33:31 Registration Request from ip 200.132.0.118:32829 [562606] >< GK: 0001:33:31 New message sent -> Registration Confirm [562608] >< GK: 0001:33:31 No.|Type |RAS Add. |Call Signalling Add.|Phone |Terminal ID. [562608] >
< GK: 0001:33:31 19 |terminal|200.132.0.118:32829 |200.132.0.118:1720 | |Fabricio Tamus [562608] >
< GK: 0001:33:31 | |Trans. Name |Party Num. |EMail |URL [562608] >
< GK: 0001:33:31 | | | | | [562608] >
< GK: 0001:34:23 Unregistration Request from ip 200.132.0.118:32829 [567894] >< GK: 0001:34:23 New message sent -> Unregistration Confirm [567894] >< GK: 0001:34:24 clearing registration number 19 [567895] >
MeetingPoint (Features)
Vídeo support:– H.261– H.263
Audio support– G.711u– G.711a– G.723
Suporte a formatos de vídeo– CIF– QCIF
Authentication
MeetingPoint supports several authentication methods:– Authentication using IP source address– Password for each room: using local
configuration files.– Radius: each user has a password– LDAP: using radius as gateway– Easy integration with any enterprise
authentication system
Rooms Configuration
There are two manners to configure rooms in MeetingPoint– Editing a file name mpcs.cfg– Using java applets resources via Web.
Rooms Configuration
Conference ID– Identification of the room to be created– Must be unique for each conference
Conference Name– Room name
Conference Greeting– Welcome message (banner) shown when a user
get in the room.
Rooms Configuration
Conference Attributes– You can choose a room with any combination of
video, audio and T.120 protocol.– You can choose all attributes, but the video
requires an additional license. Conference Mode: Choice of the type of
transmission, it can be:– normal (appears who speaks), – broadcast (appears only one speaking) or – broadcast with possibility of intervention of the
auditorium (based in a human mediator).
Rooms Configuration
Maximum Participants– Maximum number of participants of the room. – It cannot be modified during an active conference
in the room. Message
– Message that appears when the limit of connected users have been reached.
Rooms Configuration
Template– It allows that this configuration turns a model for
create new configurations.
Password– Room password, only users that have this on can
ingress in a selected room.– It can be blank in the case of an identification by
source IP address or by user password.
Rooms Configuration
Invalid Password Message– Message that appears when the user provides a
wrong password Scheduling
– schedules the initial and final dates for each videoconference.
– It can also choose the conference as permanently open or closed.
Rooms Configuration
Bandwidth – Limit the bandwidth used for the videoconference – This option consider only the H.323 protocol
necessities, ignoring the T.120 bandwidth requirements.
Frames per Second– Total of frames to be shown by second– In low speed conferences, you must take care of
always have a low frame per second sampling, to prevent image distortions.
Rooms Configuration
Continuous Presence– Allows that four people appear at the same
time, sharing the screen – Require additional license
Audio Codec– G.711 or G.711a to high bandwidth– G.723 for low speed connections.
Rooms Configuration
Video Codec– H.261 for high speed connections– H.263 for low speed connections
Resolution– CIF or QCIF.
Rooms Configuration
Time Limit– How much time a user have to stay disconnected
after your participation in a conference.– Zero (0) disable this option.
User Authentication– Type of user authentication. Values can be:
• Without authentication• IP authentication• Radius authentication
– In this case it is possible use radius to forward to another authentication system, like LDAP or SQL database, using a enterprise single sign on schema.
Rooms Configuration
Audio Latency– Minimum audio latency to permit a user
get in room (LAN, WAN or modem)
GateKeeper– To create an entrance to use in set with
gatekeeper.
Rooms Configuration
Streaming– Allows to send the conference audio and
the video to another computer as a streaming, to be distributed by another way (as RealVideo, for example)
– Require an additional license
Inviting someone to ingress in a conference
This feature is very useful to permit equipments that does not have a web client to connect in a room (like IP phone)
Used to invite someone to ingress in a meeting
The conference manager only have to access http://<server-name>/mpcs/callout.html
Choosing who will appear
In a meeting you can desire show only one speaker
You can choose who using an java applet http://<server-name>/mpcs/h323.html
Does not work with broadcast conference (Zone)
Monitoring a videoconference
Reasons to monitor– In broadcast conferences you need to
know what another people are seeing. – Some participant can use inadequate
equipment an generate an audio echo.– Helps on audio and video problems
resolution.– Helps a lot in authentication problems
Moderator
Get a real-time snapshot of client participation in a conference
Get real-time bandwidth consumption and participation statistics for a particular conference
Get information on H.323/H.320 endpoints that are currently registered
Dynamically control client participation in an active conference or in all conferences
Moderator
This guy is responsible for all conference monitoring
They do your work generally using a web applet
http://<server-name>/mpcs/mpcs.html
Monitoring
Deny User– Add a user’s IP address to deny list – This disconnects the user and prevents
the user from reconnecting Disconnect User
– Temporarily disconnect a user from a conference
– Allowed to reconnect after a time configured for that room
Monitoring
Grant Floor– Permit that a participant video, audio, and
chat can be seen by other members of the conference even if this is not otherwise permitted in the conference .
Revogue Floor– Removes the time of speaks to the user. – In the case of new Grant Floor,
automatically Revogue Floor in the old user who had the video/audio.
Radius Authentication
Can be used a Radius in another server Only one server can be used to
authentication an billing purposes Each user has your own password Each room can be configured to use or not a
radius group
LDAP Authentication
It is possible using LDAP + Radius integration
MCU ask to Radius then ask to LDAP Most used solutions uses:
– FreeRadius– OpenLdap
CISCO IP/TV 3510
Have your own gatekeeper that work independent
Can be cascade with another MCUs Can be a MP (Multipoint Processor) or a MC
(Multipoint controller)
Room Configuration
Use a proprietary cisco software client to configure the server
The client configuration software uses SNMPv1 to configure the server
A new service need to be configured before, then that associated to a gatekeeper.
How to configure a service
Description– Service Description– Ever has to start with “#”
Prefix– Service Identification – Must be numbers, “#”, “*” or “,” (comma).
Video Format– Must be choose a video protocol to be used (H.261
or H.263)
Service Configuration
Number of Parties– Maximum number of participants in the room– It depends on the transmission speed of the video
Allow Dynamic Expansion– If marked, it allows dynamic increase of the number
of participants
Video Bit Rate (Kbps)– Speed of transmission of the video.
Service Configuration
T.120 enable– If selected, permit T.120 point to point
connection between participants using a web interface.
Frame Rate– Tax of pictures by second to be shown in
the videoconference.– How much bigger the tax, minor the quality,
depending on the room.
Service Configuration
Picture Format
– It chooses the size of the video to be sent (CIF ou QCIF)
– Only enable if not continuous presence Continuous Presence
– If used, enable continuous presence resource: until for people sharing the same transmition screen at the same time (see it in next picture)
Gatekeeper Configuration
One entry to each service must be associated in gatekeeper
The name of the service must the same be of the room
Conference monitoring
Completely made by web In your browser, inform
– http://<mcu-ip-addr> – Room to be administrated
Conference Monitoring
Disconnect Participant– Detaches the participant from the
conference
Lock/Unlock Video– Display only the current video (do not
change between participants)– Useful for broadcast
Conference Monitoring
Mute/Unmute Audio– Close the audio channel to one participant– Useful for echo
Data Share– Initiates a T.120 connection with the participant
from the computer– Only works if the T.120 option services is enable
Conference Monitoring
Invite– Invites a participant to a conference– You have to know your IP address
Terminate Conference– It Finish a videoconference– All participant will be disconnected
Troubleshooting
It is not possible to establish connection. The other part refused the call.
MeetingPoint– Take care with proxy – Remember: there are transparent proxies…– Take care with firewall
Ad-hoc connections– The other part must have your client enable– The other part must be apt to receive calls– The other part can not be in a call– Firewalls are a frequent problem.
Troubleshooting
You are connected but does not receive any audio or video.
Your room have audio/video support? Sound and video drivers are correctly
configured ? Someone in your room are sending or
sharing something ? Firewall ?
Troubleshooting
You cannot send any audio or video.
Firewall ? Drivers are installed and working on ? Its microphone is on? Are other devices using the same drivers?
Troubleshooting
You can not share files, use chat or whiteboard.
MeetingPoint– Your room supports T.120 ?– Firewall filtering T.120 ports
Ad-Hoc– Does it the client support T.120 ?– Has the other part negotiated T.120?– Firewall
Troubleshooting
You can receive video on RealOne.
Do you have the right CODEC installed? Right plug-in ? Does have the RealOne support for this
protocol? Firewall ?
Firewall configuration
389 – TCP– Internet Location Server
522 – TCP– User Location Server
1503– TCP– T.120
Firewall configuration
1720– TCP– H.323 Call Setup
1731– TCP– Áudio Call Control
40000-45000– UDP– RealTime Transport Protocol
Firewall configuration
7642– TCP– Web-based GUI
7648– TCP– CUSeeMe Connections
7648– UDP– CUSeeMe Data Streams