MNET Services>Telecom Video>FAQ>Troubleshooting

What are the most important things to know?

A universal tip: make sure you have power to all involved devices. It may sound silly, but it's possible a power strip was turned off or has tripped its internal breaker.

Power-cycle your equipment (especially the main system unit [codec]). Systems are nothing more than specialized computers and computers sometimes get stuck, or go insane.

I cannot hear any audio or the audio is too low

Verify that there is not an on-screen speaker icon with the universal NO symbol through it.

Check that the volume on your television or amplifier is appropriate for your room (usually set to 3/4 full).

Check the volume control on system remote or touch-panel.

Check the red/white cables running between back of system (audio out) and TV or amp jacks (audio in). On newer flat panels the Audio & Video are on a single connector (DVI), be sure these cables are snug and the flat panel is input is set to the port the cable is connected to. Note that HDMI connectors do not have audio, only DVI.

I cannot see any incoming video

If you can see your own site only, try the layout or far-end button (system dependent) on your remote.

Try changing the monitor input, using the controls on the monitor's remote or front panel. You should see some on-screen text indicating the video source selected.

Try connecting a known good source (like a VCR or DVD player) directly to the monitor to verify its operation. If you can verify an input, move your system.s output cable to the known good port.

Some systems have a built-in color bar test in the diagnostic menus; if those are not visible, try selecting a different source.

Check the video cable between the system and monitor. Newer, high definition systems use one of several connector types. The site has for examples.

A blue screen normally indicates an invalid video source (like a turned off camera or VCR). A black screen normally means the TV/Monitor is off, or there is no signal at all at the input.

My system rings and rings but never answers

Press the call button to answer manually or check your setup menus and turn on auto-answer for incoming calls, if appropriate for your location. If you do not want auto-answer, consider setting the Do Not Disturb function on the system (if available) or shut it off.

Computer screens are barely (or not at all) readable

This is becoming a problem of the past. Any video system made in the last 5 years will have some sort of input for a computer. If you have a very old system and/or still use a Tube television, you may have a tough time seeing PC screens. If this is the case, see if the presenter can send you a copy of the slides to review locally.

I hear echo

Echoes you hear have been generated by someone else in the conference if participating in a multipoint and are most often caused by a microphone in close proximity to the system speakers, or a phone/speaker phone connected to the room you've called.

In multi-point calls, ask all the parties to mute their microphones, then call on them one by one to un-mute while you speak.

Make sure all of the participants are only connected to the MCU and not to another site on the call. All sites should conference only through the MCU.

Rule of thumb: If you hear the echo, it.s not coming from your system.

I can dial anyone by IP address but no one by E.164 identifier

This happens when your system is not registered to its assigned gatekeeper. Check the H.323 configuration and make sure the gatekeeper option is set to manual and the gatekeeper address is either, or

Some systems are connected to and controlled by a Cisco Call Manger and use SIP (email like address) to reach the far end or MCU, or like H.323, a standard 10-digit number.

If the problem persists, your H.323 ID or E.164 identifier may be already in use by someone else's system. This can be fixed by calling the Service Management Center.

I cannot get my system to register to the gatekeeper

If you system will not register, contact the MN.IT Service Management Center for video assistance. There could be a number of causes and the video team at MN.IT will assist you if finding the issue.

I just moved my system to a new room and now I can't call anyone

Your system may be connected to an inactive jack or is on the wrong local LAN segment. Video addresses are manually assigned. PC addresses are normally automatically assigned (DHCP). If the system's been moved and plugged into a jack meant for PCs, you will not get the correct (or any) IP address assigned. Most systems will display its IP address on the monitor or touch-panel for a brief period during the power up sequence. Watch for it. If you are unsure as to what it should be, check the video white pages, or contact the MN.IT Service Management Center.

You may also need a different IP address. Your local IT support should know if this is the case. If you do, contact the Service Management Center to get the IP address.

My calls disconnect if I am in a long conference

All systems have a maximum call length setting. Normally, this value should be set to zero (no limit), but factory settings are 480 or 240 minutes, or it may have been changed to an even lower limit. Firewalls also have connection timers and may sever the system's connection when it thinks it's idle too long. Contact the Service Management Center if your call disconnects by something other than a hang-up command or the system.s connection timer. Video staff will help you determine if the issue is a firewall or some other issue.

My receive video and/or audio is always broken and/or choppy

This is usually caused by a duplex mismatch between the system and the switch it's connected to. Both devices must be set the same way, usually set to auto if it.s a Gigabit Interface on the system, connected to a Gigabit switch. If connected to an older 100Mbs switch, set both for 100Mbps Full Duplex. Contact your LAN administrator or the Service Management Center for assistance. Other causes can include malfunctioning equipment, improper priority, electro-magnetic interference, insufficient bandwidth, or too many active video calls at one end of the call or the other.

Our remote locations say we sound like we're at the bottom of a barrel

An echo will occur in rooms with no acoustical treatment, such as rooms with cinderblock walls, no curtains and/or wall hangings. Even if you don't hear the echo locally, the videoconference equipment will pick it up. For an inexpensive fix, hang something on the walls that will dampen sound or use a lath frame with fabric (no striped or checked patterns).

Our remote locations complains about noise coming from our site, or another system in the conference.

The most common cause is air handler, equipment fan noise or vibrations coming up through the table. If possible, shut off the room air handling during conference calls. If that's not possible, try noise canceling microphones. To avoid vibrations from the table your microphone is on, stick felt or rubber feet to the bottom of the microphone. When all else fails, make sure users know that they need to keep the microphone muted unless theirs is the speaking site.

My calls always disconnect after a couple minutes

This is most likely due to a firewall timeout. MN.IT SERVICES does not recommend putting the video behind a firewall but if so, make sure it does not have any TCP conversation timeout parameters set. Other causes could be a very poor connection or an improper call timer setting in the video system itself.

Why does my video look choppier than my television?

Video codecs (coder decoder) break the video conference picture down to small rectangles. This is one way to achieve the large amount of compression needed to compress the signal, sacrificing some detail and color information in order to be sent at IP video rates. Videoconference resolution is (352 x 288), or (488 x 366) for rates under 1Mbps, and less than 30 frames per second. This is a noticeable difference between today.s High Definition pictures. MN.IT does have a limited number of High Definition MCU ports, available on a first come first serve basis. We hope to be able to increase our HD port count at some point during the 2015 calendar year.

How can I get a better picture?

Local picture quality is determined by many factors:

  • For the majority of conference uses, 512 or 768kbps is adequate. If a better picture and/or motion handling is required, the MN.IT video group can assist you in get the most bang for your buck.
  • When an older system is in conference with a newer one, the picture at the newer system will likely look worse that it did on a tube screen. This is normal.

Why does video degrade when multiple calls run at the same time from a location?

Not all systems capable of multiple connections will support those connections at the system.s highest rates. Check your operator or owner.s manual for details.

My receive video behaves like a poorly dubbed movie (lip-sync)

This can be caused by a host of issues. Your best bet is to hang up the call and redial. If you are part of a multipoint call, ask the MN.IT Service Management video staff to disconnect and reconnect you.

Why does my conference with a non-MNET location look bad?

Calls between conferencing systems subscribed to MN.IT video services will have their data packets delivered end-to-end with minimal delay. This is accomplished by putting special tags that prioritize traffic through the routers and switches. Calls between MNET video systems and other, non-MNET, systems will not be able to make use of priority packet marking. The data streams for the call will be delivered at the lowest priority, having a better chance of being dropped.

Why is there a very noticeable delay when conferencing with some overseas locations?

Your overseas data may be traveling via satellite, which can cause excessive delays. Long delays can also result from too much processing. In very rare instances delays are caused by signal processing.