MCUs – Configuration and Troubleshooting

Liane Tarouco

Leandro Bertholdo

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)

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] >

MCUs – MeetingPoint Configuration

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

MCUs – Cisco IPTV

Cisco IP/TV 3510

Audio protocol– G.711

Video Protocols– H.261– H.263

Video Formats– CIF– QCIF

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)

Continuous Presence

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

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 ?

Troubleshooting

Problems with multicast transmission

Are you network multicast ready?

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

Firewall configuration

24032– UDP– RTP áudio and vídeo for CUSeeme 3

1718– TCP– Gatekeeper Discovery

1719– TCP– Gatekeeper RAS