Managing media encryption and codecs

You can manage the type of media encryption and codecs used in meetings on the IBM® Sametime® Media Manager.

About this task

A codec compresses streaming data, such as audio or video, on the transmitting side and decompresses it for playback on the receiving side. Codecs reduce the amount of bandwidth required to send streaming data. Generally, higher compression conserves more bandwidth. Higher compression also results in poorer audio or video quality and requires more resources to compress and decompress the data streams.

You can change the type audio and video codecs.


  1. Log in to the Integrated Solutions Console.
  2. Click Sametime System Console > Sametime Servers > Sametime Media Manager.
  3. In the Sametime Media Managers list, click the deployment name of the Sametime Media Manager.
  4. Click the Configuration tab.
  5. Follow the procedure appropriate for your deployment:
    • Single computer deployment with all components on one computer: In the "Audio Video Media" section, keep the default encryption option as Disable or click Enable. Calls made between the Sametime Connect client and any other endpoint supporting SRTP including another Sametime Connect client or a partner conference bridge are encrypted. Audio/video conferences with three or more participants using the Sametime Media Manager or the Sametime Unified Telephony Media Server are not encrypted.
    • Non-clustered distributed and clustered deployments: In the "Audio Video Media" section, change the encryption option to Enable or Disable. This action only automatically updates the stavconfig.xml file of the Conference Manager component.
    The Sametime Community Server default refresh interval is one hour. The Sametime Connect client gets the updated server policy attribute after one hour.
  6. Prioritize the audio codecs by using the Up and Down buttons to move the audio codecs in the list.
    Sametime Media Manager supports the following audio codecs:
    Note: Sametime 9.0 client and more recent does not support ISAC and iLBC.
    • G.722.1 Annex C - Also known as G.722.1C, this codec is the low-complexity extension mode of G.722.1. It doubles the audio bandwidth to 14 kHz using a 32 kHZ audio sample rate at 24, 32, and 48 kbit/s. It is a monaural version of Siren 14.
      Note: G.722.1-32000,G.722.1-24000,G.722.1-16000 are different frequencies for G.722.1 codec.
    • G.711 - Old and widely supported narrowband codec. It requires 64 kbps bandwidth but consumes less CPU to process.
    • G.729 - Audio data compression algorithm that compresses digital voice in 10-millisecond packets. It performs audio coding of speech at 8 kbits per second. A low bandwidth codec, it is most frequently used in VoIP applications (conference calls) so that bandwidth is conserved.
    • SAC - Simple AudioCodec (SAC) is a batch audio transcoder. It converts most music and popular audio files to MP3, MP4, iPod and other MP3 player formats at high speed and with high CD quality.
    • Siren-LPR - Lost Packet Recover (LPR) protects IP video calls from packet loss. It works with commonly used codecs during video calls, including G.722.1C and others.
  7. Prioritize the video codecs by using the Up and Down buttons to move the video codecs in the list.

    Sametime Media Manager supports two video codecs:

    • H264 - Also known as AVC and MPEG-4 part 10. It provides high quality, block-oriented, motion-compensation-based video codec for video conferencing. It supports the Baseline Profile without Flexible Macroblock Ordering (FMO).
    • H264 Scalable Video Codec - Also known as SVC, this software is Annex G extension of the H.264 codec standard, which is used by most of today's video conferencing devices. It enables forward compatibility for older hardware, because the same bitstream can be used by basic hardware to decode low-resolution (720p or 1080i), and newer advanced hardware can decode high quality video stream (1080p).
    • H263 - A legacy codec of a lower quality than H264.
  8. Click OK.
  9. Restart the Sametime Media Manager.