Media Control Platform

This section describes issues with the Media Control Platform (MCP).

RTP Not Played: Announcement Application on Linux

Problem

On Linux, a call flow in which an announcement is played prior to being transferred to an agent, does not play the announcement and the RTP stream does not show up in a Wireshark test.

Resolution

This issue might be due to an incorrect configuration in the /etc/hosts file, which can cause the MCP to send an incorrect IP address in the Session Description Protocol (SDP). Some SIP phones filter RTP packets, based on the source IP address. There are two parts to this resolution:

1. Avoid this issue by ensuring that the first line of the original /etc/hosts file is not changed.

   For example, you will see the following instructions in the file:

   # Do not remove the following line, or various programs

   # that require network functionality will fail.

   127.0.0.1 localhost.localdomain localhost

   This means that the line that begins with 127.0.0.1 must not be changed.

2. It is possible that the MCP server cannot resolve the hostname of other servers in the network. In this case, there are a few options:
   • If DNS is used, ensure that the MCP server is configured to use the correct DNS server, and that it can resolve the hostname correctly (recommended).
   • Configure the other network components to use the IP address instead of the hostname.
   • Edit the /etc/hosts file for Linux, at C:\WINDOWS\system32\drivers\etc for Linux to specify the mapping between the hostname and IP address.

   For Linux, you must still ensure that the first line in the /etc/hosts file is not modified.

Network Connection Problem: SocketError

Problem

When the Media Control Platform is under load, some calls are terminated due to an error when the network connection is created. The Media Control Platform log contains error messages that refer to SocketError.

Resolution

If this problem is found on Windows, ensure that you change the registry settings, as described in the section “Modify Windows Registry Settings”, see Chapter 5 in the Genesys Voice Platform 8.1 Deployment Guide.

On Windows, after a TCP connection is closed, the operating system does not release the TCP port for 240 seconds. The registry change reduces the timeout to 30 seconds to release the TCP ports sooner for new calls.

If the problem is not resolved after the registry change, increase the port range that is allocated for the connection that runs out of ports. The following port range configuration options are available for the Media Control Platform.

• [stack]connection.portrange
• [vrm]rtp.portrange
• [vrm]client.mrcpv2.portrange
• [mpc]rtp.portrange
• [mpc]rtsp.connection.portrange
• [mpc]rtsp.rtp.portrange

Conference Video Mixing Does Not Work

Problem

When attempting conference video mixing, the calls end immediately upon joining the conference or the video is not mixed.

Resolution

Confirm that the video transcoders corresponding to the conference participant video codecs are enabled (H.263 and/or H.264) in the [mpc] transcoders configuration.

Video Text Overlay does Not Work

Problem

Video text overlay does not work, either by not displaying any text overlayed on the video, or by throwing an error in the application.

Resolution

Confirm that the video transcoders corresponding to the video file being played and the video codec negotiated are enabled (H.263 and/or H.264) in the [mpc] transcoders configuration.

If this does not resolve the issue, check that the font file you want to use is located in the directory specified by [mpc] font_paths_linux (for Linux) or [mpc] font_paths_win (for Windows).

Calls Are Not Being Accepted

Problem

SIP calls are not being accepted, and the 100 Trying message is not being sent.

Resolution

Confirm that the firewall for your machine allows traffic on all SIP related and media related ports.

Media Files Are Slow to Start Playing

Problem

Media files (in particular large ones) are slow to start playing.

Resolution

If the files are large (as can be the case with video files), it is possible that the files are being fetched multiple times, and are not being cached. Try increasing the values on [fm] cachemaxsize and [fm] cachemaxentrysize, with [fm]cachemaxentrysize being larger than the file being played, and [fm]cachemaxsize being increased in similar magnitude to the increase done for [fm] cachemaxentrysize.

If this change does not resolve the issue, try separating the video file into smaller size files.

CPU Usage Higher than Expected When Using Video

Problem

MCP CPU usage is higher than expected when video calls occur, while all participants are using the same video codec.

Solution

If all users are using the same video codec and the same profiles and levels when relevant, disabling the video transcoders can improve performance, since the MCP may be performing bitrate or framerate adjustments as is requested by the negotiated codecs. Even though this adjustment is desired based on the negotiation, it does require additional CPU resources to perform, and may not be explicitly required by the clients. Removing the transcoders can be done by removing H263, H264 and VP8 from [mpc] transcoders and restarting the MCP, or, adding gvp.config.mpc.disabledtranscoders=H264 H263 VP8 to the relevant IVR Profile.

Important

This will disable text overlay, mixed video conferencing capabilities, track cache abilities for the video, and video transcoding between codecs and different profiles and levels will not work.