My customer has about 100 branch offices and is interested in IP telephony solution . Video over ip is a part of requirements . They would like to have a simple way for point-to-point video conferencing (just one session from each branch to the headquarter) with medium quality . What is the best (and cheapest ) way to implement that?What video codec is the best for WAN links?
Recently I have designed IPVC solution for one of our customers with number of Polycom room systems connected to LAN and communicating via corporate ATM WAN and MCU located at head office.
During design I have found the following that may be of interest to you:
1. IPVC equipment to use is design independent and you can rate it in the following way: the more expensive is better.
2. According to H.323, IPVC endpoints will negotiate all parameters before establishing sessions (remember H245): video codecs (current IPVC hardware capability), audiocodecs, etc
3. Theoretically minimum of 384Kbps I would recommend for good quality IPVC session plus 10 15% for some overhead.
4. Practically during IPVC session your IPVC session bandwidth will be in between 50 75 % of 384 Kbps.
5. The very important parameter in MCU is continues presence. It can work in 2 modes: asynchronous and synchronous. When it run in asynchronous mode it can chew up a lot of bandwidth be careful.
6. The following video codecs are used today: H261 and H.263.
7. H.263 is better because it has better error correction mechanism and was designed to be used in IP networks (H.261 was designed to work in ISDN networks)
8. QOS, QOS and once again QOS on WAN routers LLQ is the way to go.
9. Use Gatekeeper on sites where more then 3 IPVC units presented (customer was surprised when I have asked him how many simultaneous sessions he wanted to allow from sites with more then 2 IPVC. But he understood my question when I presented quotation for ATM WAN link with 1024Kbps quoted only fort IPVC).
10. Use simple Zone structure, not a lot of tech prefixes, sub-zones and sub-areas.
11. It is a very big advantage to use one central Gatekeeper Master Gatekeeper for address translation and in some cases for central admission control.
My client is using Tandberg 990 MXP endpoints, and IPVC 3545 for Multi conferencing. They have totally 15 locations . When they do a point to point call between these locations the quality of both video and audion is reasonably good. But whenever the do it thru MCU the quality of video is poor. I changed the duplex and speed setting in the MCU to 100 Meg Full but still same result. Any Idea?
I would start at LAN QoS: have you implemented LAN QoS and are the trust boundaries are set correctly? Do you trust IP Prec on the switch port of the router and are you confident that you do not remark the IP Prec to 0 somewhere?
I would think it would depend on the amount of interactivity needed. You might want to consider streaming video to branches. Many codecs and MCUs allow this to dozens of sites. Instant messaging could be used for questions.
Just one branch connection to HQ is still 100 connections. MCUs don't tend to scale that high. We have an Accord MCU and two other older MCUs. We can do about 36 total connections this way. One MCU handles about 12 connections. You can get a larger one but one that would handle 100 connections will be expensive. Sometimes 384K is not enough. Ours are set at 768K for H.320. We keep the H.323 at 768K also but they could go higher. One thing you will find is lots of options. I would check out managed services also. Wainhouse Research is an excellent place to find info on videoconferencing.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.