- C H A P T E R 1 Cisco TelePresence Solution Overview 1-1. - Cisco TelePresence System 3000 1-1. - Cisco TelePresence System 1000 1-2. - Cisco TelePresence Codecs 1-3. - Cisco TelePresence Manager 1-8. - Cisco TelePresence Network Interaction 2-4. - Cisco TelePresence Solution Overview. - Cisco TelePresence System 3000. - Cisco TelePresence System 1000. - Cisco TelePresence Codecs. - Figure 1-5 Cisco TelePresence Codec. - The Cisco TelePresence 65” displays and cameras natively support 1080p resolution and utilize digital media interfaces to connect to the Cisco TelePresence Codecs. - Degree of compression applied to the original video signal. - “better,” and “best.” The “best” quality level has the least amount of compression applied and therefore requires the most bandwidth, while the “good” quality level has the most amount of compression applied and requires the least amount of bandwidth.. - Degree of compression applied to the original audio signal. - Cisco TelePresence Manager. - Figure 1-8 Cisco TelePresence Manager. - automatically sent to the Cisco TelePresence systems involved in the call. - Cisco TelePresence System Manager. - Cisco TelePresence. - Cisco TelePresence Multipoint Solutions. - Cisco TelePresence Virtual Agent. - Essentially, all components connect to it and it, in turn, connects to the network infrastructure.. - Specifically, the Cisco Unified 7970G IP phone connects to the TelePresence primary codec via an RJ-45 cable that provides it network connectivity and 802.3af Power-over-Ethernet (PoE).. - Another RJ-45 cable connects from the TelePresence primary codec to the camera, providing the camera with 802.3af PoE. - A second cable from the primary codec to the camera provides video connectivity.. - A video cable also connects the primary codec to the 65” plasma display. - Finally, an RJ-45 cable provides Ethernet connectivity from the primary codec to the network infrastructure. - A video cable connects the primary codec to the center 65” plasma display. - another of these cables connects the right display to the (right) secondary codec, and a third connects the left display to the (left) secondary codec. - Each of these secondary codecs, in turn, are connected to the primary codec via a RJ-45 cable. - The left camera is connected to the (left) secondary codec.. - The center camera is connected to the primary codec.. - The right camera is connected to the (right) secondary codec.. - Cisco TelePresence Network Interaction. - The primary codec connects to the network access edge switch via a RJ port. - Additionally, the primary codec provides a RJ-45 connection to the Cisco Unified 7970G IP phone, to which it supplies 802.3af PoE. - When the IP phone boots up, it sends a Cisco Discovery Protocol (CDP) message to the primary codec. - The primary Codec passes 802.1Q tags between the 7970G IP phone and the network access edge switch, extending the VVLAN all the way to the IP phone. - The TelePresence primary codec can be set to automatically answer the incoming call or can be set to send an incoming call alert to the 7970G IP phone. - The CallManager relays this SIP 200 OK message to the originating TelePresence primary Codec and the call is established. - Figure 3-4 TelePresence to the Executive Home (an Extension of the Intra-Enterprise Deployment Model). - TelePresence to the Executive Home CTS-3000. - Therefore, serialization delay is fixed and is a function of the line rate (i.e., the clock speed of the link). - The general recommendation for this split is 80:20, with 80% of the latency budget allocated to the service provider (demarc-to-demarc) and 20% to the enterprise (codec-to-demarc on one side and demarc-to-codec on the other). - Similar to the latency service level requirement, Cisco TelePresence codecs have built in thresholds for jitter to ensure a high quality user experience. - Similar to the latency and jitter service level requirement, Cisco TelePresence codecs have built in thresholds for packet loss to ensure a high-quality user experience. - Once the service level requirements of TelePresence are defined, then the network administrator can proceed to the next step of the QoS deployment cycle (illustrated in Figure 4-1) of designing the actual policies.. - One of the first questions to be answered relating to TelePresence QoS design is: should TelePresence be assigned to a dedicated class or should it be assigned to the same class as existing. - Telephony Cisco TelePresence. - An addition to the Intra-Enterprise Deployment Model came with the release of the Cisco TelePresence Multipoint Solution, based on the Cisco TelePresence Multipoint Switch (CTMS) product offering. - The campus is the primary Place-in-the-Network (PIN) where TelePresence endpoints connect to the network infrastructure. - —typically via an Intermediate Distribution Frame (IDF)—to the campus access-layer edge switch port.. - Therefore, the switch port connecting to the TelePresence primary codec can be configured to trust DSCP.. - Alternatively, the access switch ports can be set to trust CoS, as both the Cisco 7970G IP Phone and the TelePresence primary codec are assigned to the Voice VLAN (VVLAN) and tag their traffic with 802.1Q/p CoS values. - Only one change is recommended to be made to the default CoS-to-DSCP map, which is to map CoS 5 to EF (46) instead of leaving the default mapping of CoS 5 to CS5 (40). - This is because Cisco IP Telephony devices, including the Cisco Unified 7979G IP phone that is an intrinsic part of the TelePresence endpoint system, have the ability to identify themselves, via Cisco Discovery Protocol (CDP) to the network infrastructure. - Upon a successful CDP negotiation/identification, the network infrastructure dynamically extends trust to the endpoints, which include both the Cisco Unified 7970G IP phone and the TelePresence primary codec. - As a generic campus queuing guide, it would be recommended to assign CoS values 4 (TelePresence) and 5 (VoIP) to the strict priority queue, CoS 3 (Call-Signaling) to a (non-default) non-priority queue, and CoS 0 (Best Effort) to the default queue. - The actual QoS policies may be more complex than those shown here due to the myriad of other data, voice, and video applications on the network. - —which corresponds to the DSCP mapping for CoS 4—is set to 32 (CS4). - Under such a queuing structure, TelePresence traffic, along with VoIP, is recommended to be mapped to the strict-priority queue. - Furthermore, because the egress queuing is CoS-based, Videoconferencing/Video Telephony (AF41) will also be assigned to the strict-priority queue. - This section maps the CoS values to the Queues/Thresholds wrr-queue cos-map 1 1 1. - Interactive-Video) and CoS 5 (VoIP) to the PQ. - Under such a queuing structure, TelePresence traffic, along with VoIP, is recommended to be mapped to the strict-priority queue.. - Furthermore, because the egress queuing is CoS-based, Videoconferencing/Video Telephony (AF41) is also assigned to the strict-priority queue. - Int-Video) and CoS 5 (VoIP) to the PQ. - The cost of subscribing to realtime SP services • The “33% LLQ Rule”. - An implicit policer attached to the LLQ • A final output buffer called the Tx-Ring. - Let us first take a look at the implicit policer attached to the LLQ. - Two options exist to the network administrator. - The first is to admit both VoIP and TelePresence to the same LLQ. - However, there are some design considerations unique to the branch LAN edge discussed below.. - The first scenario consists of a Cisco router on the WAN edge connecting to a Cisco Catalyst switch, which then connects to the branch endpoints, including the TelePresence system.. - Such a policy would be similar to the simplified example provided in Example 6-3 (but with different bandwidth values for both VoIP and TelePresence, based on how many calls of each type were being supported over these links).. - If, on the other hand, TelePresence is to be assigned to a CBWFQ, then in addition to adequately provisioning guaranteed bandwidth to the CBWFQ, one additional design parameter needs to be considered, the length of the CBWFQ.. - The Tx-Ring also serves to indicate interface congestion to the IOS software. - There is a 35% hard limit to the amount of traffic that can be configured with priority queuing.. - One of the first considerations is that IPSec adds network overhead to the packets. - Therefore, a mismatch is created between the queue depths on the sender’s output interface (multiple queues of 64 packets each) as compared to the width of the receiver’s Anti-Replay window (a single sliding window of 64 packets per SA). - As discussed in the previous section, it is not recommended to deploy TelePresence over IPSec VPNs over the Internet, due to the lack of service level guarantees of the Internet in general. - As brought out in Chapter 4, “Quality of Service Design for TelePresence,” the bandwidth and service level requirements of TelePresence (including latency, jitter, and loss requirements) are very high—some are even higher than the SLAs of VoIP. - This is due to the behavior of these respective protocols during periods of congestion.. - At times applications may need to be remarked in order to gain admission to the desired SP class. - Figure 6-13 Enterprise-to-SP Mapping—4-Class SP Model Example with TelePresence Assigned to the Realtime Class Along with Voice. - As shown in Figure 6-13, in this example TelePresence traffic must be remarked on the CE egress edge to CS5 to gain access to the SP’s Realtime class. - Also, Broadcast Video must be remarked to CS2 to assign it to the UDP SP class (SP-Critical 2). - All other traffic does not require remarking to gain admission to the desired classes. - Example 6-14 Enterprise-to-SP Mapping—4-Class SP Model Example with TelePresence Assigned to the Realtime Class Along with Voice. - Now let us turn our attention to the 6-Class SP model, also illustrated in Figure 6-10. - As shown in Figure 6-15, in this second example TelePresence traffic does not need to be remarked to gain access to the dedicated, non-priority SP class to which it is assigned (SP-Critical 1). - Cisco TelePresence Manager (CTSMGR). - Cisco Telepresence Manager (CTSMGR) Microsoft. - This causes the 7970G IP phone to generate an XML message to the TelePresence Codec. - The XML message instructs the TelePresence Codec to generate a SIP INVITE, which is sent to the CUCM cluster. - Under normal conditions though, the TelePresence Codec is the one to answer the call and the SIP INVITE to the 7970G IP Phone is canceled.. - Ad hoc meetings—An end-user simply dials the extension of the Cisco TelePresence system at the other end through the 7970G IP phone that functions as the user interface to the Cisco TelePresence system. - However, due to the limitations of this approach, more advanced CAC mechanisms for TelePresence are being developed and evaluated.. - For the current release of TelePresence, it is recommended that the Cisco Unified 7970G IP phones that serve as the user interface to the Cisco TelePresence system endpoints be marked to indicate that they should not be used for emergency services calls
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