Cisco WebEx Network Bandwidth White Paper
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The spectacle of a Cisco WebEx ® session depends on many factors. Some of these factors can be administratively managed within the WebEx admin user interface, and the Cisco ® Collaboration Cloud, whereas others can be managed within the customer’s corporate network or home computing infrastructure. In this paper, we provide measurements for the network bandwidth generated during a WebEx session. This document also describes Cisco WebEx high-quality, high-definition (HQ and HD) movie technology and provides details on how it works in the context of your meetings. Eventually, this paper also offers information about storage capacity required for Network-Based Recording (NBR) functions. This paper does not contain information about the Cisco Jabber ® client.
Cisco WebEx services optimize bandwidth usage to lower the amount of data transmitted over the network, helping to reduce network congestion, increase spectacle, and improve your practice. The most significant optimizations go after.
The client software monitors text and graphics, and collective document views are transmitted. Incremental switches are detected and only these switches are transmitted again, fully optimizing the bandwidth use and preserving the user practice.
All large data transfers and file uploads are compressed, not only reducing network traffic, but also adding a level of encryption to the data stream. For more information about Cisco WebEx security, refer to our security white paper at http://www.webex.com/includes/documents/security_webex.pdf.
During application sharing, the contents of the window are dynamically updated. WebEx services incrementally update only those portions of the screen that have switched. The updates are transmitted as vector graphics guidelines and not as bitmaps.
V i d eo C omp r essi o n
Several movie compressions and optimizations have been incorporated into WebEx HQ and HD movie. The amount of bandwidth produced by movie transmission is directly related to the rate of switch of captured movie photos.
WebEx services can work through all firewalls using the Secure HTTP (HTTPS) protocol. However, WebEx will very first check if communication can be established using the User Datagram Protocol (UDP). This treatment is more efficient and reduces network traffic by approximately ten percent when compared to HTTPS. Security is achieved with use of the Transport Layer Security (TLS) 1.0 (Secure Sockets Layer [SSL] Three.0) standard protocol.
Cisco WebEx services create data flows that vary depending on the type of application being collective, complexity of the graphics, use of voice over IP (VoIP), use of movie, and other factors. WebEx services typically create network traffic when users actively share glides, desktop, and movie; or use VoIP. Simply viewing a slide presentation does not generate any activity in the meeting and transmits very little network traffic. Intense activity, such as switching a PowerPoint slide, generates intermittent spikes in network traffic, with a come back to low bandwidth use while there is no activity or no switches on the collective screen. WebEx data sharing provides up to five frames per 2nd (fps) refresh rate, requiring presenters to use the Streaming Movie Share feature for sharing movie from their computers (refer to the next section for details). The Data Share or Presentation Share features should not be used for streaming a movie file during a meeting. Figure one illustrates how to share your desktop.
Cisco WebEx Movie permits you to share movie by using the web cam affixed to your PC or Mac machine, or you can share and receive it on some mobile devices. High definition (HD) with resolution up to 720p is now available in Cisco WebEx Meeting Center and Training Center, and high quality (HQ) with up to 360p resolution is available in other centers. You can review details about WebEx web cam movie usage options and supported hardware in this section. Table one lists our movie products and their features, and Table two lists the movie resolutions that WebEx Movie supports.
Table 1. High-Quality and High-Definition Cisco WebEx Movie At A Glance
Maximum resolution (pixels) Maximum framework rates (per 2nd)
Maximum number of participants
Table Two. High-Quality and High-Definition Movie Resolutions
The following platforms support Cisco WebEx Movie.
● Linux (view only for HQ; no support for HD movie)
WebEx multipoint movie is supported on Android, Apple iOS, Blackberry, and Windows Mobile. It offers:
● Movie wall of 90p thumbnail movies
● Full-screen movie mode
● Capability to receive up to 360p movie
● Capability to send up to 180p movie (iPad two and above for iOS tablets)
Table three lists the system requirements for Cisco WebEx Movie.
Table Trio. C P U and M e m ory f or Ci sc o W eb E x V ideo (for PC and Mac)
Best Encoded (Sending) Resolution
Best Decoded (Receiving) Resolution
Minimum CPU Requirement
Single core Two.Four GHz
Single core with less than Two.Four GHz or Intel Celeron
Cisco WebEx Movie supports HD for the cameras listed below. (Refer to the latest WebEx release notes for the updated list.)
● Logitech HD Webcam C310
● Logitech HD Webcam C500
● Logitech HD Webcam C510
● Logitech HD Webcam C905/B905
● Logitech HD Pro Webcam C910/B910
● Logitech HD Webcam C920
● Microsoft LifeCam HD-5000/HD-5001
● Microsoft LifeCam HD-6000
● Microsoft LifeCam Cinema
● Microsoft LifeCam Studio
● Cisco Precision HD
● Cisco VT Camera III
● Apple iSight HD
Cisco WebEx Movie supports HQ for the cameras listed below. (Refer to the latest release notes for the
● Cisco VT Camera II
● Cisco VT Camera III
● Cisco Precision HD
● Logitech HD Webcam C920
● Logitech Quick Cam Pro 9000
● Logitech QuickCam Orbit AF
● Logitech QuickCam C905
● Logitech QuickCam S7500
● Logitech HD Pro Webcam C910
● Microsoft LifeCam HD
● Microsoft LifeCam VX-1000
● Microsoft LifeCam Cinema
● Microsoft LifeCam VX-6000
● Microsoft LifeCam NX-6000
● Microsoft LifeCam VX-3000
WebEx Movie provides two types of operation modes: single-point movie and multipoint movie. WebEx Support Center includes only point-to-point movie to support the most common type of interaction inbetween a support representative and the customer.
Multipoint movie provides a main active speaker window and thumbnail windows where up to six participants can be viewed at the same time in the participant list view; or up to five in the full-screen view. Each user has the plasticity to scroll through the alphabetical list of participants. It is preferred for very collaborative group meetings where numerous people are actively participating. Figure two demonstrates what a multipoint movie looks like. Multipoint movie is preferred for collaborative meetings or training sessions where numerous attendees are actively participating.
If you wish to display only one participant movie at a time, then when scheduling your WebEx session, simply disable the thumbnail view option. This will limit the number of active movies to one (see Figure Three).
Meeting participants can customize their own views inbetween the active speaker only and thumbnail view. Participants can customize either through the Meeting Options menu or by right-clicking the movie panel title and selecting the movie mode.
Figure three displays the options you have when setting up a meeting.
Streaming a movie file in to a WebEx meeting permits you to share a movie file during a meeting. This method of movie sharing is different from the desktop sharing and the website sharing features. Similar to webcam movie, streaming uses scalable movie coding to encode and decode numerous layers of movie bit flows.
In Cisco WebEx Meeting Center, Training Center, and Event Center, you should distinguish inbetween the webcam movie usage for movie presence of the participants in the meeting and the collective movie file feature, which the presenter uses to play the movie file to the audience from the presenter’s computer. The webcam movie refers to videoconferencing in real time, encoded and sent to the receiving clients using the Cisco Collaboration Cloud.
Webcam movie is used primarily for videoconferencing. The Streaming Movie File feature is a movie that is encoded and streamed to other meeting participants as collective content during a meeting. This streaming movie feature contains the movie and audio (if it is included in the file) and does not emerge in a multipoint videoconferencing pod as an active speaker. You can play, pause, or stop it from the file-sharing tab; it is similar to a previously uploaded presentation or whiteboard (refer to Figure Four).
From the Presentation Desktop, click the arrow next to Share My Desktop, select Share File, and select your movie file. The following media file formats are presently supported: WMV, WMA, WAV, MP3, ASF, AVI, MPG, MPEG, MOV, FLV, F4V, QT, and MP4 and WRF. (Note: The computer of the person sharing the file must be capable of playing the file).
The Cisco WebEx Meeting Center has adopted the H.264 standards-based Scalable Movie Coding (SVC) for movie compression to supply adaptive standard-quality (SQ), high-quality (HQ), and high- definition (HD) movie. HD (720p) movie is presently available in Meeting Center and Training center.
The movie engine consists of all the fundamental movie processing modules, including capture, encoding, transmission, receiving, decoding, and rendering. It also includes supporting modules for error control, congestion control, bit-rate adaptation, and encryption.
The SVC encoding protocol permits the captured movie to be separated into numerous layers of resolutions, framework rates, and quality. In the WebEx movie encoder implementation, raw movie sequences are compressed into a single base layer and several enhancement layers before they are transmitted to the receiving clients. The base layer in the compressed movie bit rivulets provides a relatively low movie quality and can be independently decoded. Enhancement layers serve as add-ons for the base layer to improve the movie practice. If more bandwidth is available, then more enhancement layers will send, resulting in better movie quality.
Similarly, when network congestion occurs for any participants, the clients could save bandwidth by receiving fewer enhancement layers, little by little degrading the movie quality while maintaining the best movie practice and dynamically adjusting the quality to switching conditions of the network or the participant’s computer.
Depending on various conditions, such as user eligibility, subscription modes of the receivers, capability of camera and PC, network conditions, and others, one or more of the available resolutions can be encoded at the same time that the movie is sent. On the receiving side, the client automatically selects and decodes one specific resolution. This encoding and decoding capability results in a higher bandwidth requirement for transmitting movie compared to receiving movie.
WebEx supports various frame-rate ranges. On the sender side, it depends on the camera capture capability and available computing and bandwidth resources. On the receiver side, it depends on the bandwidth and computing resources.
● Up to 30-fps HQ and HD movie is supported in a one-on-one meeting (only two participants point to point [P2P]).
● Up to 24-fps HQ and HD movie is supported in a multipoint meeting (three or more participants).
● Up to 18-fps 180p movie is supported in a one-on-one meeting (only two participants P2P).
● Up to 12-fps 180p movie is supported in a multipoint meeting (three and more participants).
● The WebEx client may stop sending and receiving the movie if the network or hardware environment conditions deteriorate drastically.
Administrators cannot control the default and maximum bandwidth levels for multipoint HQ and HD movie.
The levels and framework rates are managed automatically by software, and administrators cannot override the software control. Administrators can choose to disable the HQ/HD mode and limit the movie to 180p resolution. Refer to Figure five for the “Turn on high-quality video” or “Turn on high-definition video” checkboxes. This setting is a site wide-setting that affects all users. Refer to the site administrator’s guide for more details.
Figure six shows the HQ and HD settings available for a user profile.
Figure seven illustrates the settings available for meeting scheduling.
Most of the time, the bandwidth that the movie flows consume on your network depends on the type of movie view modes. Table four provides an example of the different modes with movie and average bandwidth usage. You can use information from this table to calculate the approximate bandwidth consumption per client.
Table Four. Modes with Movie and Average Bandwidth Usage