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Technical FAQs

Below are answers to the popular questions our customers ask most frequently. If you do not find your answer here, have further inquiries, or would like to suggest a new FAQ, please contact us.

1. What is Telepresence?

Telepresence, in videoconferencing, refers to a set of conferencing technologies which allow a person, or a group, to feel—via a videoconference—as if they were present – while in-fact being at a remote location, locally or around the world.

2. What is High Definition or HD?

High Definition (or HD) signals require an HD television or computer monitor in order to be viewed. High-definition video has an aspect ratio of 16:9 (a.k.a. widescreen). Standard-definition television (SDTV) has a 4:3 aspect ratio.

High-definition television (HDTV) resolution is 1080 or 720 lines. In contrast, regular digital television (DTV) is 486 lines (upon which NTSC is based) or 576 lines (upon which PAL/SECAM are based).

To achieve true HD videoconferencing, it must achieve these standards:

  • The bandwidth necessary to transmit the larger packets of data – typically 1 MB or above
  • A resolution and a frame rate (usually 30 fps) that is defined as HD (in descending order):
    • 1080p (1080 progressive scan lines)
    • 1080i (1080 interlaced lines)
    • 720p (720 progressive scan lines)
  • An aspect ratio of 16:9 or widescreen (vs 4:3 aspect ratio with standard TVs)
  • Visual equipment that will allow these HD resolutions be transmitted, with the available bandwidth necessary:
    • HDTV monitor (e.g. Plasma, LCD)
    • HD video camera and HD-capable codec

3. IP or ISDN? Which network is right for me?

This depends on the amount of usage you have planned. ISDN is generally a lower monthly charge but on top of that you pay a per minute/hour fee for usage. IP generally has a higher monthly charge but there is no per minute/hour fee for usage—therefore a flat monthly rate, regardless of usage. If you already have a large ISDN infrastructure in your company and only make one or two short video calls per month, then ISDN may be the better solution. If you plan to implement a converged network and are a medium to heavy user of videoconferencing per month with multiple video rooms, then IP may be a better choice.

4. What is VoIP?

Voice over Iinternet Protocol. Please refer to our Business VoIP FAQs page.

5. Which ISDN numbers or IP addresses can I use to test my system?*

ISDN Network (Max Call-In Bandwidth: 512Kbps):

703-848-7992 or 703-848-7998

IP Network (Max Call-In Bandwidth: 768Kbps): or

* These test numbers are for VSGi customer-use only.

5. When I do an IP video call over the public Internet, I can connect, but I do not receive an audio or video signal. However, the other side can see and hear me fine. What can I do to fix this problem?

This is most likely because your organization’s Firewall is blocking the incoming video from the public Internet. Have your network administrator configure the Firewall for H.323 Video.

6. What ports do I need to open on my network’s firewall?

For Cisco/TANDBERG systems use the following video port ranges:

TCP 1720
UDP 1719 (only if using a Gatekeeper)
TCP 5555-5560
UDP 2326-2406

TCP 1720
TCP 5555-5560
UDP 2326-2365

For POLYCOM systems use the following video port ranges:

TCP 3230-3243
UDP 3230-3285

VSX & ViewStation
UDP1719 (only if using a Gatekeeper)
TCP 3230-3235
UDP 3230-3253

TCP 1720
TCP 1503 (T.120)
TCP/UDP 3230-3237

7. What is the default password for my videoconferencing system?

For Tandberg Systems:
The default password is “TANDBERG”

For Polycom Systems:
Use the serial number as the password. The password can be found on the system information screen.

8. I am in a video call using the public internet. I am connected with the far end, however, the video is choppy or freezes. What can I do to fix this problem?

Since using the public Internet can occasionally cause increased latency and/or packet loss, you might try reestablishing the video call at a lower bandwidth. VSGi offers video network services, via ISDN lines or IP circuits, that are consistent and allow for 100% packet delivery. VSGi’s vIPConnect network service guarantees 100% throughput for video– at all time and under all network conditions.

9. I have a new plasma and setup videoconferencing system that needs to be mounted on a wall. What is the recommended height the plasma should be mounted?

38″-41″ off the floor to bottom of the plasma.

10. What color should I use for my videoconferencing room?

The best choice for wall paint color is a light blue. VSGi recommends Benjamin Moore paint numbers 1627, or 829. The worst wall color to use is white, as it creates too much of a contrast and can literally erase the faces of participants casting facial feature in deep shadow.

A light to medium colored conference table will reflect light upward and make shadows disappear from the user’s faces. Do not use a white or black laminate or other high intensity colors that could reflect too much light and wash-out a participant’s face. Also keep in mind that the pattern on the laminate should be camera-friendly. VSGi recommends the following laminate colors (Wilson Art) – Featherstone, Pebble, Pewter, Sea Breeze, Bronze Legacy, Grey Tigris, Saffron Tigris, Fusion Maple, Wild Cherry. If you plan to use a veneer conference table Natural Cherry, Medium Cherry, and Natural Maple are excellent choices. Avoid patterns that are large or repeated on furniture, walls, or clothing. The room does not have to be monochromatic, but just keep it simple.

11. How secure is videoconferencing over the public Internet and what can be done to overcome it?

IP videoconferencing can be secured using different methods. Setting up encryption and firewalls (will require network administrator) are some examples. Depending on your requirement and your network setup, additional methods or devices can be installed. VSGi offers an array of video network services which can help your organization get started — regardless of your current network infrastructure.

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