ShowTable of Contents
Introduction
This article
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provides a Sametime 8.5 audio and video (A/V) guide, with links to useful references
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summarizes features of Sametime 8.5 audio and video
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shares some good practices and troubleshooting techniques
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provides diagrams of A/V call flow to assist with planning and troubleshooting
This document is an accumulation of knowledge and lessons learned from many teams' contributions – issues uncovered from IBM Software Services for Lotus (ISSL) customer engagements and architectural discussions, lessons learned from test cycles, and Sametime Development’s in depth knowledge of the component and its intended design.
Review system requirements
First of all, review the Lotus Sametime 8.5 Detailed System Requirements document to make sure you are aware of the requirements and limitations of the Sametime 8.5 components for audio and video (A/V).
Requirements important for A/V are as follows:
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In the Sametime Media Manager Server section, note that Sametime 8.5.0 Media Manager is supported only on Windows and Linux platforms.
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The notes for the Sametime Media Manager Server section are as follows:
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Sametime Audio/Video Reflector (STUN/ICE server) is not supported
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No IPV6 support
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No FIPS support
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WebSphere Application Server 7.0.0.3 Network Deployment (included with installation)
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In the Audio / Video Client Requirements section, note the following:
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Windows XP or Windows Vista operating systems
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Memory requirements of a minimum of 128 MB of memory for video
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Requires a Sametime Media Manager server for voice chat and video calls unless using Classic Meetings
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Pre-Sametime 8.5 clients cannot participate in voice chat and video calls using the Sametime 8.5 Media Manager server
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(Stated another way, this means all participants must be connected to the same community used by the Media Manager, and all participants must be using Sametime 8.5 Connect client for Audio and Video)
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Default bitrate (CIF 352x288@15Fps 384kbps)
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6-person video limit in chat or meeting
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10-person audio limit in chat or meeting
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For a positive audio video experience a network latency of no more than 100 milli-seconds is required between the clients and servers. In addition a network bandwidth of of 200-300 kbps is required per video stream between clients and servers. A network bandwidth of 30-40 kbps is required per audio stream. The network bandwidth requirements will vary depending on the quality of audio, video, and number of streams selected.
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Sametime video codecs provide many resolution choices, from SQCIF to Wide Full HD (1080p). The higher the resolution, the more CPU, display memory, and graphics card power are required. Machines equivalent to Lenovo T60 can handle CIF and VGA, but HD will require Intel Core 2 Quad or better CPU and at least 256 megabytes of display memory.
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In the Audio / Video Client Requirements section, the Web client is listed as not supported, except on the Classic Meetings on only Windows platform.
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What this means is that A/V in Web meetings requires that such A/V Web Meetings be started through the Sametime 8.5 Connect client. Web A/V directly through a Web browser is not supported (namely, opening a browser, and typing in the URL directly to a Sametime Meeting Server). A Web A/V meeting must be entered through the Sametime Connect client user interface.
Check setup for A/V
For audio and video to work properly with Sametime 8.5 clients, ensure that you have the following installation and configuration in place:
Sametime 8.5 audio and video features
This section outlines what's new in 8.5 audio and video features and changes from previous versions of Sametime.
Client changes
In Sametime 8.5, the point-to-point audio/video and n-way audio has been radically changed in both the stand-alone and embedded clients. A Media Manager (also known as Media Server) is now used to perform all types of A/V calls, even for point-to-point calls. The 8.5 client now uses SIP and TCSPI to establish A/V calls; the 8.5 client does not support legacy phone grid based audio/video.
As noted in client interoperability in the Information Center, all participants must use 8.5 clients for A/V features; there is no backward compatibility for A/V with older Sametime clients. Sametime 8.5 clients are not backward compatible with previous versions for audio and video. Even with Media Manager, 8.5 clients will not be able to place audio and video calls to older clients (including SUT 8.0 clients). This limitation in backward-compatibility is due to the major improvements introduced in 8.5 with new audio and video codecs and multi-way audio/video, including a change to SIP-based standards. Therefore, there is a one-time switch to the new technology.
When an 8.5 client interacts with a pre-8.5 client, you see the following behavior:
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If the 8.5 client has access to Media Manager, a call invitation from an older client will be declined automatically
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If the 8.5 client does not have access to Media Manager, then an older client might display an error message when trying to call an 8.5 client (depends on the older release)
If you are upgrading from Sametime 8.0.2 client to Sametime 8.5, then make sure the Media Manager is also installed. Without the Media Manager, there will be no computer device and UI controls to start audio or video calls; they will be disabled.
The Information Center topic “Managing media codecs” lists the supported codecs for Sametime 8.5, summarized as follows:
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Video: H264, H263
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Audio: ISAC, iLBC, G.722.1-32, G.722.1-24, G.722.1-16, G.711
Audio/Video feature comparison by version
The following table shows audio-visual features by the version which includes them:
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Feature
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8.0.2 without ICE
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8.0.2 with ICE
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8.5.0
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8.5.2 |
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Point-to-point (P2P) AV
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Supported
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Supported
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Supported
Media Manager Server Component required
Non NAT
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Supported
Media Manager Server Component required
NAT'ed Support a TURN Server is required
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Multiway (n-way) AV
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Supported
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Supported
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Supported
Media Manager Server Component required
Non NAT
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Supported
Media Manager Server Component required
NAT'ed Support a TURN Server is required
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NAT and traversal between heterogeneous networks crossing firewalls
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Only via Reflector, has inconsistent performance
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Uses ICE to support many configurations, including using Reflector/TURN server
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Not supported
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Supported
Media Manager Server Component required
NAT'ed Support a TURN Server is required
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Backward- compatible
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Yes
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Yes
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No
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No |
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AV in online meetings
(using Connect Client)
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Yes
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Yes
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Yes, using 8.5 Connect Client
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Yes |
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AV in online meetings
(browser, not using RCP)
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Yes
(Classic Meeting Server MRC)
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Yes
(Classic Meeting Server MRC)
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AV in online *new* Sametime 8.5 Meeting Server requires 8.5 Connect Client
Classic Sametime 8.5 server still features AV in Java-based online meetings
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Yes, Requires a Sametime Media Server and Sametime Proxy Server Compontent. |
Making and joining calls
There are multiple ways for users to make or join a call or video call in Sametime 8.5, such as using the telephony icon or using the “Call” or “Start Video call” menu options from the Contact list. For steps and sample screen captures, refer to the following resources:
Voice and video with Lotus Sametime software
Lotus Sametime Help > What other ways can I communicate beyond text chats?
Meeting integration
When combined with the Lotus Sametime Media Manager, meeting rooms can be enhanced with audio-visual features.
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Using audio and video in chat (not Sametime Meetings) for point-to-point and multi-point does not require a meeting server. A/V is integrated with meetings when using the Sametime client.
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For audio/video to work in meetings, the Meeting Server and Media Manager are both required.
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Meeting rooms can be created with A/V or, in the case of an instant meeting, A/V can be added later to the room.
By default, only six participants with video are supported in a meeting room. To change the setting, refer to “Limiting participants in a video conference.”
For steps and sample screen captures of using audio-visual features in meetings, refer to the following resources:
Online meetings with Lotus Sametime software
Lotus Sametime Help > Make conference calls and use video
Third-party service provider support
Starting with Sametime 8.5, TCSPI has been extended to support video. Previous third-party TCSPI service providers can still be used with the Sametime 8.5 Community Server, but to do so telephony service needs to enabled. All new TCSPI third-party service providers must be deployed on the Media Manager. At this time, only one external provider being in use is supported. The external provider can use its own SIP based MCU to switch RTP data between Sametime Connect clients and different SIP endpoints. A sample “MyAV” TCSPI adapter is included in the 8.5 Software Developer Kit (SDK). The following diagram, an excerpt from the SDK, shows this sample MyAV adapter integrated to Sametime 8.5:
About the Media Manager
This section describes the Sametime Media Manager, including its architecture, components, and installation options. The Sametime Media Manager allows users to start point-to-point and multipoint A/V calls with each other using the Connect client and meetings.
Architecture
The Sametime 8.5 Media Manager consists of three server components:
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SIP Proxy and Registrar
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Conference manager
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Packet switcher
For details on each component, refer to the Information Center topic “Lotus Sametime Media Manager.”
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The Proxy and Registrar handles endpoint registration and SIP-based call routing.
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The Conference manager hosts TCSPI adapters (one internal and one external) and provides conference focus functions (as in RFC 4353).
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The Packet switcher routes audio and video to participants based on voice-activated switching. Note that point-to-point A/V calls do not use the Packet switcher.
All Media Manager components are WebSphere-based applications, and they must be running for audio and video to work. These components can be on a single machine or distributed across multiple WebSphere nodes.
This diagram shows the components of the Media Manager and their port ranges:
The diagram shows all the Media Manager's WebSphere applications running in a single server deployment of the Media Manager.
Proxy and Registrar
The SIP Proxy and Registrar contains and provides a list of all registered components and clients. It loads server configurations from proxy.xml and registrar.xml files. All SIP messages pass through the SIP proxy and are routed to the registered endpoints. There can be no SIP communication if the SIP Proxy and Registrar server is down. You can install multiple SIP Proxy and Registrar components and cluster them for high availability and failover.
Conference Manager
The Conference Manager provides call control, management, and notifications. The Conference Manager also starts the Sametime Telephony service on start-up. It loads internal and external TCSPI service provider using server configurations. It loads server configurations from the stavconfig.xml file in WebSphere Application Server. The Conference Manager registers with the SIP Proxy and Registrar that it is running. Clients get notified of the Telephony service and TCSPI service provider via VP protocol. Clients then register with the SIP Proxy and Registrar. During conference calls, the Conference Manager acts as a back-to-back user agent (B2BUA) for the client.
Packet switcher
The Packet switcher is responsible for receiving and sending media streams from endpoints to other endpoints in a conference. The Switcher works on audio streams to determine the active video stream to send to the participants, a process known as Voice-Activated Switching (VAS).
The Packet switcher loads server configurations from the stavconfig.xml file in WebSphere Application Server and registers with the SIP Proxy/Registrar. It periodically sends availability messages to the Conference Manager. In an A/V conference call, it acts as a SIP endpoint.
It is important to note that the Packet switcher dynamically allocates ports to all audio and video conferences and reuses these ports once A/V calls are ended.
Clustering of Packet switcher is not supported, but there can be multiple packet switchers on different hosts. If you have a Conference Manager cluster, then the Packet switcher is registered with the Conference Manager cluster, and each cluster member uses the same Packet switcher.
Installation options
You install the Lotus Sametime Media Manager using the Sametime System Console (SSC). The SSC can manage only one Media Manager server. (While it is possible to install without using the SSC, that configuration is not advised for production environments.)
You can use the “All components” deployment plan to install a stand-alone Media Manager in proof-of-concept environments.
If you are clustering Media Manager, take note of the following items:
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Clustering requires proper planning
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Only the Conference Manager and SIP Proxy and Registrar can be clustered
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The Packet switcher cannot be clustered, but there can be multiple switchers
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The “All components” installation (Proof of concept/Pilot installation option) cannot be used for clustering
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At least three machines are required for vertical clustering where each component uses the SSC deployment manager:
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1 x Conference Manager: Network Deployment – Primary node
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1 x Proxy and Registrar: Network Deployment – Primary node
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1 x Packet Switcher: Network Deployment – Primary node
Additional Packet Switchers can be deployed on different machines
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WebSphere Application Server Proxy server can be used on the same machines
Steps can be found in Sametime 8.5 Information Center topic “Clustering Lotus Sametime Media Manager components.”
A/V in Sametime Classic Meetings
The Domino-based Sametime 8.5 Classic Meeting Server allows for online Web meetings using the Sametime Meeting Room Client (MRC). This Java-based Web client allows for A/V to be used in online meetings. It interacts with the Sametime Classic Meeting Server; it does not interact with the new features in the 8.5 client, nor the Media Manager (and its components), nor the Sametime reflector.
The audio-visual features of the Sametime Classic Meetings client are:
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All A/V packets relayed through the Sametime Classic Server
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Audio supports the G.723, G.711 and iSAC codecs
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Video only supports the H.263+ codec
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Neither the client or server supports NAT traversal, but the server does have the option to tunnel AV packets over TCP.
Only a limited number of H.263 video resolutions are supported for this classic client, namely only the following H.263 CIF formats are supported:
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CIF, 352x288QCIF, 176x144
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SQCIF, 128x96
Newer webcams might not support lower resolutions. The Classic Meeting Client does not prevent the user from choosing an unsupported format. As a result, video will not appear even though audio continues to function properly. There is no anticipated change for the Classic Meeting Client to support another codec or additional formats, so users are encouraged to try using different webcams to resolve the problem.
Best practices
Review good practices in the following resources:
Practices that are important to highlight:
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All participants must be connected to the same community used by the Media Manager. All participants must be using Sametime 8.5 clients.
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One of the key factors affecting video quality is available network bandwidth. The higher the video resolution, the more bandwidth is required for better quality. Adjust and manage video bit-rates accordingly on the Media Manager Video Resolution configuration page.
Troubleshooting resources
General troubleshooting tips can be found in the Lotus Sametime Wiki article “Troubleshooting the Sametime 8.5 Media Server.”
If you need to collect diagnostic data (logs and trace files) to review, either on your own or when working with IBM Support, refer to “Collecting Data: Lotus Sametime Media Manager.”
Known issues and field notes
This section highlights some known issues and troubleshooting notes. You can also search technotes about known issues or frequently asked question in the IBM Support Portal. Or browse through Sametime 8.5 technotes on audio/video.
Problem: Poor video quality
Solution: Video quality is a combination of the end user's camera as well as the compression level set on the server + network bandwidth and latency available to support it.
Test the camera performance outside of Sametime to check whether Sametime is a factor. For example, you might notice that a laptop-integrated camera has poorer quality than an external camera even outside the Sametime environment.
There have been issues with cameras not working with Sametime if the Windows default drivers are used. The camera might test fine in Windows, but the Sametime client does not recognize the camera or show it in the preferences. To resolve, use the camera-specific drivers. If in doubt about whether the drivers are a factor, the UIM logs are a source to check for data.
Problem: Getting 'ST_CONNECT_NOT_PRIVILEGED' or ‘ST_CONNECT_HOST_UNREACHABLE' error in media server logs.
Solution: Add the media server IP in the trusted IP list of the ST community server. For more details see technote 1429413 and Information Center topic “Configuring a Lotus Sametime Community Server to allow connections from Conference Manager nodes”
Problem: AV does not work for n-way and meetings call, only point-to-point AV calls work.
Solution: All n-way and meetings AV calls require that at least one Packet Switcher is available to the Conference Manager.
Typically this problem occurs due to configuration settings
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Verify that a PacketSwitcher.info file is present in the media server logs directory
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Open the stavconfig.xml file under the DM profile directory in WebSphere Application Server and verify that the value of packet switcher host is the same as the machine on which it is running
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Might need to remove any host aliases from the OS hosts file
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Media Manager must be deployed on the primary host name of the machine if there are multiple IP/hostnames available on the machine
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Verify that none of the clients and media server are behind a NAT firewall
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Clients and media server should be able to open connections (or ping) in both directions
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UDP must be allowed through firewalls. Test by disabling firewalls on client and server and verify A/V
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Diagnose the media server logs and enable tracing if necessary
Problem: UDP port conflicts
Solution: Identify if UDP ports are already being used. If Sametime 8.5 finds that UDP port is being used, or there is a conflict, it will not try to use it again. Refer to the instructions from the following Sametime Information Center topics to see if you need to modify the UDP ranges:
Modifying the dynamic port range to improve Packet Switcher performance
Managing UDP ports for voice chat and video calls
Problem: How to modify the maximum number of participants in an A/V session?
Solution: By default, only six participants with video are supported in a meeting room. To change the setting, refer to “Limiting participants in a video conference.”
Problem: Some participants in a meeting room might see "waiting for call to start...." though the moderator has started the A/V call already
Solution: A hotfix is available; see technote "Meeting participant sees Waiting For Moderator in an instant meeting room" (#1427723).
Call flows and interactions
This section provides diagrams of various call flows or configurations to help you plan or troubleshoot in your environment.
Call flow for a point-to-point AV call
The following diagram shows how two Sametime 8.5 clients handle a point-to-point A/V call. Client A starts a call with Client B by sending TCSPI requests to Conference Manager through the Sametime Community server. The conference manager creates a new conference and communicates with both clients over SIP through the SIP Proxy/Registrar. Finally the clients negotiate the media and start sending audio and video data directly to each other.
Figure 9.1 - Point-to-point call
NOTE: Point-to-point A/V calls do not use the Packet switcher; however, it is included for consistency with other pictures in this article.
Call flow for a multi-point AV call and AV meetings
The following diagram shows how three or more Sametime 8.5 clients handle a multi-point A/V call. Note that the same sequence also applies to A/V calls in Sametime meetings where there can be one or more clients. Client A starts a call with Client B and Client C by sending TCSPI requests to Conference Manager through the Sametime Community server. The conference manager creates a new conference and communicates with the Packet Switcher and all three clients over SIP through the SIP Proxy/Registrar. All the clients negotiate the media with the Packet Switcher and start sending audio-video data to it. The Packet Switcher sends the data back to all participants in the call using voice-activated switching.
Figure 9.2 - Multi-point call
Point-to-point interception
In this diagram, endpoint A starts a point-to-point call with endpoint B by sending TCSPI requests to the conference manager. Both endpoints are then added to the conference by the conference manager and receive a SIP INVITE request. After getting SIP ACK from the conference manager, the endpoints are able to send/receive media between each other.
Figure 9.3 - Point-to-point interception
Escalation from point-to-point to multi-point
This diagram shows how a point-to-point A/V call between endpoints A and B is promoted to a multi-point call by adding endpoint C. The steps are similar when a multi-point call is started directly. The new endpoint is added to the existing conference by Conference manager using TCSPI and sent a SIP INVITE request. Endpoint C then negotiates media with the Packet Switcher and start sending/receiving media data from it.
Figure 9.4 - Escalation to multi-point
Media Manager Installer and System Console interaction
The diagram depicts the steps involved when the Media Manager is installed using a deployment plan created in the Sametime System Console. All of the Media Manager configurations are captured by the installer and stored in the stavconfig.xml file, which is used by the Conference Manager and the Packet Switcher components of the Media Manager.
Figure 9.5 - System console
Media Manager admin flow
In this diagram, the SSC pushes all the Media Manager's configurations and client policies on to the SSC database, which are then pulled by the Community server and used by the Sametime 8.5 client. The Community server will synchronize any configuration or policy changes made on the SSC server using the default time interval of 60 minutes.
Figure 9.6 - Administration flow diagram
Conclusion
You can achieve a successful implementation of audio/video features in Lotus Sametime 8.5 by understanding the components, checking requirements, and planning. If problems do occur, review best practices, troubleshooting resources, and call flow diagrams.
Sametime 8.5.1 resources
This article was written before Sametime 8.5.1 was released. To learn of A/V improvements and changes in Sametime 8.5.1, review the following resources:
Sametime 8.5.2 resources
This article was written before Sametime 8.5.2 was released. To learn of A/V improvements and changes in Sametime 8.5.2, review the following resources:
NAT traversal for audio/video
Bandwidth Manager
Multiple A/V partner integration
Call & video controls for web browser meetings