Classification Tools | Network Quality of Service Technologies

Classification tools serve to identify traffic flows so that specific QoS policies can be applied to specific flows, such as TelePresence media and control flows. Often the termsclassification and marking are used interchangeably (yet incorrectly so); therefore, you need to understand the distinction between classification and marking operations:

• Classification refers to the inspection of one or more fields in a packet (the term packet is used loosely here to include all Layer 2 to Layer 7 fields, not just Layer 3 fields) to identify the type of traffic that the packet is carrying. When identified, the traffic is directed to the applicable policy-enforcement mechanism for that traffic type, where it receives predefined treatment (either preferential or deferential). Such treatment can include marking/remarking, queuing, policing, shaping, or any combination of these (and other) actions.
• Marking, on the other hand, refers to changing a field within the packet to preserve the classification decision that was reached. When a packet has been marked, a trust boundary is established, upon which other QoS tools later depend. Marking is only necessary at the trust boundaries of the network and (as with all other QoS policy actions) cannot be performed without classification. By marking traffic at the trust boundary edge, subsequent nodes do not have to perform the same in-depth classification and analyses to determine how to treat the packet.

MQC performs classification based on the logic defined within the class map structure. Such logic can include matching criteria at the data link, network, or transport Layer (Layers 2 to 4) or even at the application layer (Layer 7)

Collaboration Tools | Cisco TelePresence

Two common tools found in most conference rooms today are speaker phones and projectors. Most of today’s meetings consist of one or more individuals sharing documents with a group of people, often located in multiple locations. Using a web/audio conferencing tool such as WebEx allows users to simultaneously share documents and bridge audio between multiple sites, while using a projector to locally display content for in-room participants.

The Cisco TelePresence codec provides these features, allowing non-TelePresence users to participate, through audio only, in a TelePresence meeting and share documents with all meeting participants.

Auto Collaborate is a feature that allows any user in a TelePresence room to easily share any application on a laptop PC or an item from an in-room document camera. As with any in-room projector, a user simply connects a laptop to the VGA cable on the TelePresence table to start sharing. With an optional ceiling mounted or desktop document camera, users also have the option of sharing additional items such as documents, fabric samples, and so on with TelePresence participants. Users simply select the document camera softkey on the 7975 Series IP Phone and use the simple touch-screen phone interface to power on and control the document camera. Users don’t need to worry about granting control for sharing from one PC to another or a document camera. The last device to become active is the device that displays in all TelePresence rooms.

The VGA cable and document camera in the TelePresence room connect directly to the codec that automatically displays the image locally, using the system projector, while encoding the image and sending it to all TelePresence systems in the meeting. Application data is compressed using H.264 at 5 frames per second (fps), which is sufficient for sharing slides or items from a document camera but, in most cases, is not sufficient for full-motion video. If full-motion video is a requirement, a high-speed presentation codec can be added to the system providing 30fps for document and video sharing.

Most TelePresence meetings have attendees who don’t have access to a TelePresence room. TelePresence meetings can easily connect to a web/audio conferencing application such as WebEx or Meeting Place to accommodate non-TelePresence participants.

When the TelePresence meeting is in progress, one TelePresence room connects to the audio bridge, essentially adding the audio bridge to the TelePresence meeting, using the audio add-in feature. At the same time, the presenters in the TelePresence rooms join the web conference, allowing shared content to be viewed by all TelePresence and audio/web participants.

After the TelePresence meeting is connected to the audio/web conference, non-TelePresence participants can participate in the meeting using audio and view or even present, shared content throughout the meeting. The overall experience is similar to today’s meetings where a group of individuals meet in a conference room, dial into an audio bridge using a speaker phone, use a projector to locally display content, and share the local content with remote participants using web conferencing.

Audio add-in is a feature allowing audio-only participants to participate in a TelePresence meeting. From any TelePresence room a user simply selects the conference softkey on the 7975 Series IP Phone and dials the number of the audio participant or audio conferencing bridge. The audio add-in participants are connected through the initiating Telepresence system where audio is decoded, mixed, and played out all system speakers. The audio is then re-encoded in AAC-LD and sent to all Cisco TelePresence rooms in the same meeting.

Audio and Video Multiplexing

Each Cisco TelePresence system connects to the network using a single 100/1000 Ethernet connection. All TelePresence systems support multiple audio and video channels, allowing support for system video, audio, and shared data. Single-screen TelePresence systems support two audio channels and two video channels, whereas three screen TelePresence systems support four audio and four video channels. RTP multiplexing minimizes the number of video and audio connections across the network, providing a single video and single audio connection between any two Cisco TelePresence systems.