Cisco Telepresence Implementation for Telekom s Corporate Requirements

Transcription

1 Cisco Telepresence Implementation for Telekom s Corporate Requirements Zdravko Stafilov 1 1 Makedonski Telekom, Orce Nikolov bb, 1000 Skopje, Macedonia Abstract. The Cisco Telepresence system was the platform of choice for Deutsche Telekom and its affiliates as a videoconferencing solution for corporate requirements. This article explains the main Cisco Telepresence components and concepts, but its primary focus is on the concrete implementation of four Telepresence systems in three of the Deutsche Telekom s affiliates - Magyar Telekom, Makedonski Telekom and Crnogorski Telekom, emphasizing the explicit implementation in Makedonski Telekom. It explains the network infrastructure, the latency, jitter and packet loss setup for the Telepresence system, the bandwidth requirements and calculations, as well as the site topologies in three different cities where the nodes are implemented - Budapest, Skopje and Podgorica. The current Telekom s solution is based on Cisco model TP3000 on all four locations, which is a high-end Telepresence system that has three Codecs (1 master and two slaves), three cameras and three monitors. The article also describes the detailed physical requirements of the room where the Telepresence systems are implemented and explains in details the room design in Makedonski Telekom, including images from the room. It stresses out the specific factors that must be considered when designing a multipoint implementation such as this. The usage of the Cisco Telepresence System, or T-Presence as the Deutsche Telekom affiliates branded their teleconferencing system, has given benefits is in three ways financial as the biggest one, marketing and sales. 1 Introduction Magyar Telekom, Makedonski Telekom and Crnogorski Telekom have selected Cisco Telepresence system as a tool for videoconferencing and have implemented a joint Telepresence infrastructure over a dedicated MPLS VPN network. The Telepresence system is an IP only solution based on SIP. As such main considerations are given to bandwidth, CallManager integration, dial plans, QoS and security. The Telepresence network consists of 4 Cisco Telepresence Systems (CTS) model TP3000 which are deployed at the following four locations: Budapest, Krisztina - Magyar Telekom; Budapest, Infopark - Magyar Telekom; Skopje - Makedonski Telekom & Podgorica - Crnogorski Telekom. The Scheduling, Call routing components and the Multipoint switch are hosted at Magyar Telekom s data centre in Budapest. The Telepresence infrastructure is separate from the MT s existing infrastructure and it is not interconnected at any point. The overall design of the solution is displayed on Figure 1.

2 Figure 1. Telepresence Network Topology

3 2 Telepresence Solution Components and Concepts Telepresence solution s main component is the Codec. Codec provides the inputs for high definition cameras and outputs for high definition displays. Codec also provides the audio inputs for microphones and audio outputs for speakers and compresses the video and audio inputs with H.264 compression into IP packets for delivery on the IP network. Codec is a two way real-time communication platform so that you can see and hear the far end at the same time they are seeing and hearing you. The rapid delivery of the information is very important. Real time communications must have very low delay and uniform delivery of the packets across the network [1]. QoS is also very important to the Telepresence solution. The Codec is packaged in a complete Telepresence solution and Cisco offers two different packages: TP3000 and TP1000. The current telekoms sollution is based on TP3000 on all 4 locations. The TP3000 is a high-end Telepresence system that has three Codecs (one master and two slaves). It also uses a Cisco IP telephone for user operation. The systems are expected to connect with other IP video endpoints using SIP only and use the CallManager for translation between SCCP (Skinny Call Control Protocol, Cisco propriatary protocol) or H.323 endpoints. The combination of a phone (Cisco 7970 IP phone) and the Telepresence endpoint in the room present to the user a seamless environment where both devices act as if they are a single entity. The intent is that to have a phone in the room which is acting as the user's primary interface for both the phone and the Telepresence device. The TP3000 consists of three HD displays which simulate immersive environment [3]; three Codecs connected together, three microphones, three speakers, three cameras and three strip lights. Electronics and displays are mounted in the front structural facade provided with the system. No closet rack space is required. The Telepresence Triple consists of one Primary and two Secondary Codecs. The Primary Codec connects to the network infrastructure via Gigabit uplink. The two Secondary Codecs connect to the Primary via Fast Ethernet. The 7970 IP Phone connects and gets its power via the Primary codec (Fast Ethernet). The internal interconnectivity is displayed on Figure 2. The Telepresence Information Management is a software suite that consists of system management tools, real time diagnostics tools and reporting tools, and is located centraly at Magyar Telekom. Additional features of this suite include visual network management and billing software systems as well as real time video call support software systems. These tools and capabilities are required to meet operational requirements for fault management (alarming), configuration management, performance management, capacity planning and usage monitoring (call detail records).

4 Figure 2. Cisco TP3000 internal interconnectivity The typical Telepresence end-user is a business user with basic familiarity of telephone usage. It is expected that they may be uncomfortable with unfamiliar technology such as video conferencing systems [2]. As previously mentioned, the associated Cisco IP phone provides the primary end-user interface. It is envisioned that Telepresence specific end-user functions will be provided under the services menu of the phone. The phone is configured to use an HTTP server running on the Telepresence master unit to retrieve the end-user interface screens. The resulting user actions are sent to the same HTTP server running on the Telepresence master who in turn invokes the necessary software components on the unit to accomplish the desired action. Any resulting status information or changes of end-user screens are returned for displaying on the phone. 3 Physical Telepresence Requirements and Design Each of the four implementations of CTS3000 (TP Triple ) systems include: One Cisco Telepresence Primary Codec Two Cisco Telepresence Secondary Codecs One Cisco Unified 7970G IP phone Three 65 HDTV flat-panel displays Three HDTV cameras Three microphones Three (stereo) speakers One input for auxiliary audio One input for auxiliary video

5 The room requirements and specifications [5] in terms of dimensiong are presented on Figure 3. and images of the actual design of the Telepresence room in Makedonski Telekomunikacii are presented on Figure m (Target) 0.46m (min) 0.6m (min) 0.6m (min) 5.8m (Target) Door Location 6 2.4m (min) Minimum Room dimensions Network and Power access Room Dimensions: Table location constraint: Recommended: Front wall minimum clearance (for maintenance) 6.7m x 5.8m x 2.44m (22 x 19 x 8 ) Minimum: 0.46m Maximum: Side walls minimum clearance (for maintenance) 9.45m x 7.01m x 3.66m (31 x 23 x 10 ) Minimum: 0.6m Back wall clearance from table edge: Minimum:2.4m Figure 3. Cisco TP3000 room requrements A minimum of 300 Lux in overhead lighting is required. The Telepresence triple system comes with built-in lighting sources that deliver studio lighting to the room. If the room has windows, a window treatment such as curtains or blinds where natural light is obscured is recommended. Curtains with black-out backing are preferred. Curtains also provide acoustical enhancements that lessen room reverberation. The rooms in the Telekoms where the TP3000 is implemented don't have windows, so there is no need for a window threatment.

6 Figure 4. Images from the Telepresence room in Makedonski Telekom

7 4 Network infrastructure 4.1 Current Telepresence Systems Bandwidth For the bandwidth usage we have to reference to the agreed 4 Mbps (as a target bandwith for an acceptable picture quality [4]) to define the nature of the network traffic and how to quantify it, including any bursty nature of the traffic [1]. The bandwidth usage is restricted on a rolling window basis to a target bandwidth. This bandwidth can burst up to 20% higher to a ceiling over this rolling window. So, having in mind that the rolling window is 1 s and the target bandwidth is 4 Mbps, then in any given period of 1s the total bandwidth should average out to 4 Mbps (The rolling window means that the 1 s window can be arbitrarily picked.). The ceiling dictates that within the rolling window, the peak at any given moment in that rolling window will never go above 20% higher than the target average. So, the maximum burst in a 1s rolling window could be as high as 4.8 Mbps (but will not be sustained at this rate). The burst is only on the Variable Bit-Rate (VBR) video stream and not the Constant Bit-Rate (CBR) audio stream. The rolling window is currently defined as 1 s, but is subject to change. The following are the bandwith calculations for the actual implemented TP3000 system, at 1080p (one way bandwidth without IP overhead): 3 primary video streams (4 Mbps each): 12 Mbps 3 primary audio streams (64 Kbps each): 192 Kbps 1 auxiliary audio stream: 64 Kbps 1 auxiliary video stream: 400 Kbps TOTAL (Average): 12,656 Kbps TOTAL (Including Bursts): 15.3 Mbps For all configurations, there is also an additional VoIP call of 64 Kbps that can be made from the Telepresence system, but this traffic is not between the two Telepresence endpoints in the call. This call could be to a VoIP phone, MeetingPlace Bridge, or out to the PSTN network through a voice GW Latency, Jitter & Packet Loss The latency between two Telepresence endpoints should be <150 ms (one-way). The configured threshold behavior is that if a latency is >200 ms, a warning message is displayed Experiencing network delay, and if the latency is >400 ms, a 2nd warning message is displayed Experiencing severe network delay. Jitter within the system should be less than 5 ms peak, for a total of 10 ms peak to peak. Meaning, for example, if the average latency is 50 ms, then the min and max latency should not be outside of ms (or 10 ms peak to peak). Configured threshold behaviour: >20 ms, a warning message is displayed Experiencing network congestion ; >40 ms, the system will lower motion handling from Best to Good.

8 Packet loss should be under 0.05% from end to end. Configured threshold behaviour: >0.1%, a warning message is displayed Experiencing network congestion ; > 0.2%, the system will lower motion handling from Best to Good. If such bad conditions persist on the network, the call will be disconnected and an error message will be displayed Call could not proceed due to excessive network congestion Site topologies Figure 5. Network topologies of the four locations where CTS3000 are implemented

9 Figure 6. Makedonski Telekom Telepresence Network Topology 5 Multipoint Design Today, multipoint capability is a required component for any collaborative application. Over 40% of today s meetings consist of individuals from three or more sites. Multipoint for Cisco Telepresence allows three or more Cisco Telepresence Systems to participate in a virtual meeting. Simply put, multipoint Telepresence calls are handled in much the same manner as today s audio conference calls. Each Cisco Telepresence System dials directly into the Cisco Telepresence Multipoint Switch (CTMS), by either manually dialling the conference ID, or using the One Button to Push feature on the Cisco 7970G IP Phone within the Cisco Telepresence room. All video and audio streams from CTS rooms are terminated on the CTMS and switched among the CTS rooms in the meeting [4]. The first factor that must be considered when implementing multipoint is network bandwidth. It s important to remember that multipoint meetings for CTS are simply multiple point-to-point meetings terminated on a CTMS. A single CTMS is capable of simultaneously terminating 12 CTS 3000 rooms, at 15.3 Mbps each, with a maximum throughput of 180 Mbps. In the actual case with four CTS 3000 rooms, each with 15.3 Mbps of bandwidth, this results in 61.2 Mbps that are guarantied at Magyar Telekom s central site where the CTMS is located.

10 During a Multipoint session, the call flow between the Telepresence endpoints goes through the Multipoint switch [6]. The latency, jitter and packet loss between the CTS endpoint during the Multipoint call must still be that of the point-to-point call. That means that latency between the CTS endpoint and the Multipoint switch should be half minus the delay added by CTMS site. 6 Benefits from using the Cisco Telepresence System The T-Presence (the way the Deutsche Telekom affiliates branded the teleconferencing system based on Cisco Telepresence) has given benefits in three ways from using the CTS-3000: Marketing - Introducing this innovative technology had positive impacts on the T- brand; - Communication campaigns are built on using T-Presence and IP telephony in the Telekoms and its subsidiaries internally, and this is serving as reference to the Telekom s top customers. Financial - Using T-Presence instead of frequent traveling, resulted in considerable cost saving Sales - Telekom owned T-presence is utilized for demo/rent purposes; - Potential clients; - Enterprises with foreign owner and/or subsidiaries; - Clients with large outsourcing deals. References 1. Hirche, S., Buss, M.: Telepresence control in packet switched communication networks. In:. Proceedings of the 2004 IEEE International Conference on Control Applications, vol. 1, pp , IEEE (2004) 2. Chen, W.C., Towles, H., Nyland, L., Welch, G., Fuchs, H.: Toward a compelling sensation of telepresence: demonstrating a portal to a distant (static) office. In: Proceedings of the conference on Visualization '00, pp , IEEE Computer Society Press, Los Alamitos, CA, USA (2000) 3. Ebara, Y., Kukimoto, N., Leigh, J., Koyamada, K.: Tele-Immersive Collaboration Using High-Resolution Video in Tiled Displays Environment. In: Proceedings of the 21st International Conference on Advanced Information Networking and Applications Workshops, vol. 2, pp , IEEE Computer Society, Washington, DC, USA (2007) 4. Cisco Systems: Cisco Telepresence Network Systems Design Guide. (2009) 5. Cisco Systems: Cisco Telepresence Deployment Planning Guide. (2007) 6. Cisco Systems: Cisco Telepresence Network Requirements, TSBU Technical Marketing, EDCS (November 2007)