Video Conferencing Bandwidth & Quality of Service (QoS)

This web page complements the e/pop FAQ and Data Sheet providing additional details and illustrations on the topics of IP video bandwidth consumption and quality of service.

Fixed-site boardrooms and telepresence studios generally use some form of dedicated network routes and Internet connections. Dedicated routes are required to achieve the high bandwidth (lots of data) and low-latency (fast), full-motion, full-screen video.

These dedicated routes are expensive, complex if you are not familiar with detailed grades of service, and most importantly, sit idle while not being used.

The latest generation IP video conferencing software and online services (also called video over IP) are capable of running over existing networks. They run over dedicated routes too, which is useful for “apples to apples” comparisons between boardroom hardware and IP conferencing software. But the value proposition and most popular configuration is running over existing networks. This often leads to questions regarding bandwidth consumption and quality of service.

e/pop Web & Video Conferencing

e/pop is an excellent example of multiparty IP video. e/pop is firewall and proxy friendly, an especially important requirement for business and government conferencing, where each user is behind their own, separate firewall. Many peer-to-peer and classroom legacy products fail when it comes to business applications over the public Internet. Today, over 99% of business users are behind a firewall, and future network security requirements are always growing. While firewall and proxy traversal are required for online business meetings, they are not the primary topic of this web page. For more information on firewall traversal, please refer the IP video technology white paper.

e/pop Bandwidth Consumption & Video Codecs

Video applications consume bandwidth similar to web browsing, web conferencing, desktop sharing and VoIP. Video differs in one important respect, video is continuous. When sharing a desktop, bandwidth is usually only consumed while you are moving the mouse around or changing the display; with VoIP, only while you are talking; and with e/pop PowerPoint and document sharing, only when the document is initially shared, thereafter only page change commands go “over the wire”.

The quality of a video over IP depends on the network connection and Internet access, including bandwidth or data carrying capacity, and latency, or the speed of the connection. Note it is possible to have a high-bandwidth connection, but long latency (slow). For example, a high-end satellite link may provide good bandwidth, but still have one or two seconds of latency.

Other considerations include the video codec, the compression quality setting (low, medium, high), size (1/8th screen, 1/4 screen, full screen), and frame rate (1 to 30 frames per second, 6 default). Some industry veterans say they can tell the difference between the video coder/decoder too. e/pop uses MPEG4 as a default, with optional H263 and H263+.

e/pop users do not need to worry about these details, as the meeting host can go to the Conference menu and select Set-All-Video to low, medium or high, and then Play-All. Or just say Play-All, and e/pop will use defaults. Conference hosts can also make individual video settings if desired. Say for example, making the primary speaker’s video the largest, or “floating” their video (see screen shots above). e/pop will not allow settings that are not possible under current network conditions, on a connection-by-connection basis. Once set, e/pop also dynamically optimizes, raising or lowering the frame rate in response to changing real-time conditions, all without interrupting the host or meeting participants.

	In the screen shot shown at left, the small videos are running at low quality, 177x144, also known as 1/16th screen or “postage stamp”. These use ~28 kbps each, and multiparty video conferences are possible over virtually any broadband connection.
	In this example, the videos are running at medium during a desktop sharing session (CAD). The conference room window was “floated” by the conference host and stretched, but the native resolution is 320x240, also known as 1/4th screen. At default 6 frames/second, this will use approximately 128 kbps for each person talking or moving around.
	The last example shows the conference host at high quality, full screen (640x480). At 6 fps this will be ~256 kbps, at full motion, or 30 fps, it will run ~512 kbps. Bandwidth consumption is not linear due to compression involved.

Bandwidth Guide

An e/pop user will generate an uplink load averaging 28 kbps or less for VoIP; with video ranging from ~28 kbps (low), ~128 kbps (medium, 6 fps, default), ~256 kbps (high), all the way up to ~512 kbps for full-screen video conferencing (high, 30 fps). The latter is not recommended except for internal conferences, dedicated routes, or other specific circumstances where exceptional (DS3 and above) bandwidth is available (same as traditional boardroom hardware). These averages vary by customer, quality of video capture and so on. For example, better video cameras may use, on average, more bandwidth as they have better sensitivity.

User uplink bandwidth is cumulative at the server, so the server requires a symmetric Internet connection.

USER CONNECTIONS:
Any broadband connection. DSL and other “asymmetric” connections with limited uplinks will support low and medium video at best.

SERVER CONNECTIONS:
This can be complex, as various scenarios may include all internal conferencing, conferencing with a mix of internal and external participants, or one employee conferencing with hundreds of external participants. However, the following chart, albeit oversimplified, is a useful guide. Please contact WiredRed for assistance. We help our customers every day with this topic, and the easiest solution of all is often starting out with e/pop as a hosted service.

ON-PREMISE SERVER:

Standard DSL
At any video setting – not recommended (for server), use hosted service

Symmetric DSL
Note: figures below depend on actual grade of service delivered. This type of service often varies with distance from customer physical location to telephone company network access point (NAP) and can be as little as 128 kpbs uplink in rare cases.

Low quality video – 5 to 10 total
Medium quality video – up to 5 total
High quality video – not recommended (for server), use hosted service

T-1
Low quality video – 5 to 10 total
Medium quality video – up to 5 total
High quality video – up to 2 total
For larger scale meetings, use hosted service

DS-3 or Better

Low quality video – up to practical limits, 10-20 per meeting
Medium quality video – up to practical limits, 10-20 per meeting
High quality video – up to practical desktop limits, 2-3 per meeting

Note that without a conference room build-out, you can only display two full screens at a time with a standard dual monitor set-up

With DS-3 or better, multiple meetings in these ranges are possible. Please contact WiredRed for details and assistance. For large applications, consider also hosted servers below. See also Typical Configurations.

HOSTED SERVER:

Low quality video – up to practical limits (screen display area)
Medium quality video – up to practical limits (screen display area)
High quality video – up to practical desktop limits (screen display area)

Multiple online meetings routine; in addition to video participants, there can be dozens or hundreds of conference participants.

Hosted services can be activated with one phone call. With e/pop, you can switch from hosted service to on-premise software at any time. If any of the material on this page is unfamiliar, usage is hard to predict, or there are other unknown variables involved, then hosted services may be the best alternative. Please contact WiredRed for a live demo or impromptu Q&A session.

Quality of Service Defined

Quality of service (QoS) as broadly defined refers to control mechanisms that allow IT staff to provide different priority levels to different applications and users on their network. QoS discussions can be a challenge because of differences between computer networking and telephony terms, and growing informal notions of responsiveness associated with this topic. QoS is important though, because VoIP and video are typical application areas, and the user experience may benefit from a good QoS implementation, especially for internal conferences. More on QoS…

e/pop QoS

With respect to e/pop audio and video over IP, the following are some important points regarding this topic:

QoS settings are made on the network equipment, not e/pop. e/pop operates within industry standards and tags its packets, operates on known ports, IP addresses and host/domain names. Beyond that, the priority, latency and load controls are set at the router(s).
Older QoS facilities used packet inspection and required applications to tag their packets, but modern routers allow controls by additional means including application, network service (IP address or host/domain name), users, and more. e/pop tags its packets, so its traffic can be managed by older equipment.
QoS is relevant on your network, settings generally do not work over the public Internet, where many of the tags are ignored and you do not control the routing infrastructure. For IP conferencing over public networks, the user application experience may not benefit; but internal users and other prioritized applications might. This may change in the future as real-time connections become more prevalent, more specific grades of Internet service come online with end-to-end control, and more organizations become fortunate enough enjoy Internet2 connections.

Summary

In summary, e/pop observes industry standards for tagging, allowing customers to control the priority and quality of service for e/pop voice (VoIP) and video communications. QoS settings apply to company controlled LANs, they generally do not work for packets going over the public Internet.

e/pop is extremely bandwidth efficient, and employs state-of-the-art technology for mixing data, VoIP and video packets, and dynamically adjusts to real-time conditions on each conference connection. e/pop generates an uplink load of roughly 28 kbps or less for VoIP; with video ranging from ~28 kbps to ~128 kbps at the most popular low and medium settings. High quality video is easily possible even with desktop peripherals, but requires more bandwidth (see above).

e/pop users need not become video experts, they can simply select Play-All at the Conference menu. For those that choose to make specific settings, e/pop will not allow settings that exceed current network conditions, plus it adjusts automatically to real-time changes in throughput. Most importantly, e/pop allows IT staff and WiredRed hosted service customers to put limits on users, VoIP and video features for peace-of-mind in limited bandwidth scenarios.

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