White Paper. Power Protection for Voice over IP, and other New, Mission-critical Network Applications

Power Protection for Voice over IP, and other New, Mission-critical Network Applications

Executive Summary 3 1. Voice over IP Market Opportunity 4 2. Power over Ethernet and IP Telephony 5 3. Powering IP Phones 6 4. How to Select the Appropriate Power over Ethernet Mid-span 8 5. How to Size and Select the Appropriate UPS 8 6. Remote management 11 7. Fit to other «Edge» Network Applications 12 Summary and conclusions 13 Appendix 1 : The Basics of Enterprise IP Network 14 Appendix 2 : Types of IP Telephony Installations 16 2

Executive Summary New, mission critical applications are being deployed at a fast rate on enterprise networks. Voice over IP (VoIP) is one of the most important ones, both in terms of deployment numbers and specificities (convergence technology, high requirements for quality of service and availability). Moving to IP Telephony is a key decision point in the evolution of an enterprise network. Independent of either the evolutionary or revolutionary approach to migration, in the end, the enterprise will have converted its entire voice network to be VolP based, while demanding equal characteristics of the traditional telephony, such as availability and voice quality. A new technology, Power over Ethernet, greatly contributes to make these deployments both simple and highly available. This technology, now an IEEE standard (802.3af) endorsed by all network actors under the name "Power over Ethernet (PoE)", allows to power IP-connected devices such as IP phones and Wireless LAN access points, over the existing LAN cabling infrastructure. This allows not only a very convenient and cost-effective powering of the phones (no local desk DC power needed), but also a simple, centralized power protection of the whole installation directly from the switch/wiring closet. PowerDsine, the leader in Power over Ethernet technology, and one of the major contributors in the development of the IEEE 802.3af standard, and MGE UPS Systems, one of the world leaders in high availability and high quality power solutions, have joined their efforts to outline in this document, some of the key power-related aspects to consider when deploying VoIP solutions. Using PowerDsine Power over Ethernet products for IP Telephony, and MGE UPS Systems power protection devices, IT managers and Facility managers and users will get the same level of availability from their VoIP architecture as they experience with the traditional circuit switched telephony systems. For more information on the PowerDsine Power over Ethernet mid-span products and our additional 802.3af compliant products, as well as the IEEE 802.3af standard for DTE Power via MDI, look us up at: www.powerdsine.com For more information on MGE s complete range of UPS systems and high availability power solutions, look us up at: www.mgeups.com 3

1. VoIP Market Opportunity Enterprise Voice over IP, also known as IP telephony, refers to the solution (hardware, software, services) that is used to transmit voice over the above-described enterprise data network, using the Internet Protocol (IP). Many closely linked applications (such as videoconference over IP, etc.) also exist, which also leads to the more generic acronym «XoIP» to which most of this paper also applies. Voice over IP brings significant advantages over traditional («circuit-switched») enterprise telephony networks : Reduction in carrier circuit charges (true when Voice over IP is carried over the Internet) Enhanced applications:! integrated messaging! voice-enabled web sites! desktop video conferencing, Integrated management systems and strategies Increased flexibility, reduction in overall complexity, elimination of circuit redundancy For these reasons, Voice over IP is currently experiencing a very fast growth, with analysts estimating compounded annual growth rates of 40% to 70%. The overall PBX market experienced a down year in 2001 but still represented sales just shy of $7 billion in the United States alone. This relatively large market is expected to grow over the next few years and could easily reach $8 billion by 2005. Total line shipments of 9.9 million in 2001 are predicted to grow to 13 million by 2006. As displayed in figure 2, the new Iine shipments for IP-enabled and IP-PBX systems are predicted to grow at a faster pace than circuit-switched line shipments and could completely displace circuit-switched new line deployments by 2005, according to Gartner Dataquest. IP PBX Market Forecasts (Line Shipments) (Gartner Dataquest) 14 12 New lines (in millions) 10 8 6 4 IP PBX IP Enabled Legacy (circuit-switched) 2 0 2000 2001 2002 2003 2004 2005 2006 Figure 1 : IP PBX Market Forecasts (Line Shipments) Other researches confirm that in 2003, the value of shipments of IP PBX equipment will, for the first time, surpass revenues generated by legacy PBXs. IP PBX seats are projected to grow from 1.9 million in 2001 to 42 million in 2007. The IP Phone handset shipments in 2002 has reached well over 1 million units with 30% growth compared to 2001. ln 2003, an additional 60% growth is forecasted, with vendors like Cisco, 3Com, Nortel, Mitel, Avaya, Alcatel and Siemens which are the market leaders. All vendors understand the importance and need for Power over Ethernet in VolP installations and are thus designing their next generation IP Phones to be compatible with the Power over Ethernet standard, the IEEE802.3af (see below). 4

2. Power over Ethernet and IP Telephony 2.1. What is Power over Ethernet? Power over Ethernet is a revolutionary technology that integrates data, voice and power over standard LAN infrastructure. It is the means to supply reliable, uninterrupted power to Internet Protocol (IP) telephones, wireless LAN access points, network cameras and other Ethernet devices, using existing, commonly used Category 3 (4 pairs) and Category 5 cable infrastructure. Power over Ethernet technology saves time and cost of installing separate power cabling, AC outlets and wall warts (AC adapters), as well as eliminates the need for a dedicated UPS (Uninterrupted Power Source) for individual devices. A single UPS placed centrally close to the switches and the Power over Ethernet source will indeed protect both the switches and all the connected devices. The power delivered over the LAN infrastructure is automatically activated when a compatible terminal is identified, and blocked to legacy devices that are not compatible, thus protecting them and the infrastructure. This feature allows users to freely and safely mix legacy and Power over Ethernetcompatible devices, on their network. There are two main implementations of Power over Ethernet Power Source Equipment (PSE): The mid-span - A patch-panel like device, residing between an ordinary Ethernet switch or shared media device and the terminais. Mid-spans are also referred to as "Power Hubs" or "Power Injectors". Power is added to the spare wires on a category 5 Cable while the data is passed without interruption. The end-span - Power over Ethernet enabled Ethernet switch. Power over Ethernet is integrated into the switch, and supplied directly from the data ports. Figure 2 : Power over Ethernet Architecture in the Enterprise Power over Ethernet technology was approved by the IEEE Standards Board on June 12, 2003 (IEEE 802.3af-203). 5

2.2. Key Drivers for Power over Ethernet in IP Telephony application The main key drivers for Power over Ethernet in the IP Telephony market are availability and simplicity of installation: Availability is a key consideration in IP Telephony Consider the promise of running telephony over data networks, where you can greatly benefit from new applications, such as unified messaging together with significant cost-savings in personnel and equipment using a single voice-data network, Before Power over Ethernet, corporations could not commit their mission-critical voice systems to run on the data networks, losing data during a power outage is one thing, but losing data and voice during an outage is something else entirely. By supplying power over the same cable as the data network, these systems can now deliver the kind of reliability expected from a business class phone system, Everyone has high expectations for voice service availability. A common goal is to consistently achieve 99.999% availability with 5.3 minutes of downtime per year or less, PowerDsine understands that high availability and reliability are absolute requirements for ail mission-critical applications, including IP telephony solutions. By connecting a UPS to a Power over Ethernet Mid-span in the communication room, the entire IP Telephony network is becoming more reliable and ensures continuous operation during a power outage. To understand the theoretical availability for power (North America), the following characteristics are presented. The following data varies from site to site and some areas like Florida are expected to experience an order of magnitude higher of non-availability. The data is also representative of Japan and Western Europe: The average number of outages sufficient to cause IT system malfunction per year at a typical site is approximately 15 90% of the outages are less than five minutes in duration 99% of the outages are less than one hour in duration Total cumulative outage duration is approximately 100 minutes per year Based on the theoretical availability and the power protection strategy, the availability levels of five nines or higher requires to install Power over Ethernet mid-spans backed up by a UPS system with a minimum of one hour battery life. Power over Ethernet technology, wh en implemented in a VolP installation, ensures full reliability and availability of the telephony network by eliminating power outages effects. Ease of Installation Power over Ethernet offers a simple means for IP Phone handsets installation, eliminating the need for a separate Ethernet link and dedicated AC Power outlet. A single cable is used to transport voice, data and power to desktops. The IP phone is connected to the Ethernet switch and the Mid-span, from which it gets data and power, and the PC is connected to an Ethernet port on the phone. 3. Powering IP Phones An IP telephone can be powered via one of three options: 1. Power over Ethernet mid-span - Power supplied over the Ethernet cable via an external Power over Ethernet Mid-span. 2. Power over Ethernet end-span - Power over Ethernet integrated into an Ethernet Switch, which offers standard IEEE 802.3af Power over Ethernet. 3. Power supplied via an AC adapter ln the market, different Power over Ethernet products exists, however, not all are compatible with the Power over Ethernet standard IEEE 802.3af. Like all global standards, it is significantly important to maintain an open environment to enable interoperability between different terminal vendors. 6

ln environments where an existing Ethernet Switch has been previously installed and is providing VolP QoS capabilities, there is no need to purchase and install a new Ethernet Switch to provide Power over Ethernet functionality. ln this case, the simplest means to power the IP Phones over the LAN infrastructure is to add an external Power over Ethernet Mid-span (see figures 3 and 4). The advantages include savings in installation costs, preservation of existing infrastructure while supporting pre-standard as well as IEEE 802.3af standard terminals. Figure 3 : Installing IP Phones with Power over Ethernet Mid-span Power over Ethernet End-span products are currently beginning to be available in the market, however some are not IEEE 802.3af compliant. It is recommended that enterprises will not purchase proprietary solutions (i.e. not 802.3af). Enterprises will be best served by an infrastructure that continues to support an open, multiservice environment. The third way to power IP phones, i.e. through an AC adapter, has significant drawbacks : not only this is more cumbersome as two cables (data and power) Figure 4 : Integration of Ethernet Switches, Power over Ethernet Mid-span, UPS in the Network Rack have to exist on each user s desk, but also (unless each user is equipped with a local UPS), any utility outage will result in the IP phone not being available. It is much more convenient to plan a centralized UPS at the Ethernet switch and the PoE Midspan level that will protect all the IP phones. This is of course also valid if the Ethernet switch/midspan are powered through an outlet that is permanently power protected by a large centralized UPS at the Enterprise site level. 7

4. How to Select the Appropriate Power over Ethernet Mid-span PowerDsine s Power over Ethernet Mid-spans utilized for IP Telephony applications, are the 6, 12 and 24 port units. These units fit low to high port densities of IP Phones. As usually done in Ethernet Switches installations, 25-30% of the mid-span ports should be left unused for future growth, in case the IP Telephony network is expanded, or the number of users is increased. For example, two spare ports in the 6-port mid-span, three spare ports in the 12-port mid-span and 6 spare ports in the 24-port mid-span should be left unused. PowerDsine Power over Ethernet Mid-span Family PowerDsine family of Power over Ethernet midspan devices, with over one Million of ports already deployed by PowerDsine and its satisfied partners, provides the most field-proven reliable solution. PowerDsine provides a full Iine of Power over Ethernet mid-span devices, including 1, 6, 12 and upto 24- port devices, targeted for IP Phones (an other compliant devices) from different vendors, such as Cisco 79xx, Nortel i2004, Mitel 50xx, Avaya 46xx, Siemens Optipoint 400/600 and Alcatel 4035/4037/4098. Figure 5 : PowerDsine 6001, 6006, 6012 and 6024 1/6/12/24-Port Power over Ethernet Mid-spans : 1, 6, 12 and 24-port Power over Ethernet Mid-span Powers Cisco and IEEE 802.3af terminals Advanced auto-sensing algorithm for non powered device protection Web-based SNMP management option 1 U high, 19" rack mountable LED Status indications IEEE 802.3af 5. How to Size and Select the Appropriate UPS 5.1. «Right-size» the UPS The level of power typically consumed in a communication room with Power over Ethernet capabilities is approximately 400% of that consumed by networks without Power over Ethernet. For example, a typical 24-port Ethernet switch consumes an average of 100W, whereas a simple installation of an Ethernet switch providing a power solution to 24 IP Phones requires powering backup in the range of 400W. More specifically, with the PoE standard specifies up to 15W per attached device, the typical Power over Ethernet-compatible terminals consume in the range of : 3-5W for IP phones, 6-10W for wireless access points, and 9-12W for IP cameras. ln a typical communication room, eight stackable Ethernet switches are installed, providing service to 192 users, the power backup requirements can be fulfilled with a UPS of 1.5KW. However, to achieve the same level of reliability in a converged voice environment with Power over Ethernet, the UPS backup solutions should be in the range of 6KW. In order to size the UPS requirement, one can use this attached worksheet that gives a quick first estimate. It is advised to plan for future growth and thus include a safety margin in the UPS VA sizing. 8

Equipment Rated input Power in Watts X Number of stacked switches X 1/Power Factor = Power in VA Switches without POE support X X = Switches with POE support X X = Mid-span units X X = Other equipment X X = Extra power = X% margin for future expansion Total UPS Sizing = Example : switching closet with 144 IP lines (6x 24-ports switches) providing connectivity to 72 users, each having a PC and an PoE-powered IP phone: Equipment Rated input Power in Watts X Number of stacked switches X 1/Power Factor = Power in VA Switches without PoE 170 X 6 X 1,10 = 1122 support Switches with PoE support 500 X 0 X 1,10 = 0 PoE Mid-span units 400 X 3 X 1,05 = 1260 Other equipment 0 X 0 X 1,43 = 0 Extra power = 40% margin for future expansion Total UPS Sizing = 3335 For this environment, a UPS such as MGE s Comet Extreme 4,5KVA would be a great fit. MGE s Pulsar Extreme 3000VA would also fit, with lower margin for future expansion (additional VoIP phones and an additional mid-span for instance). Backup time considerations are also important and can also point towards a larger UPS, that will be able to sustain longer outages for a given load (see under). Figure 6 : MGE s Comet Extreme UPS Note : the example above assumes that the switches and phones are power-protected at the switch closets level. In some companies, the whole building is equipped with outlets that are centrally protected at the site level, through a large centralized UPS. Of course, this represents an equally good solution. To calculate the exact amount of power being used in a Power over Ethernet environment, with a view to saving costs by «right-sizing» the appropriate UPS, it is important to calculate the exact amount of power consumed by the IP Phones. This can be done using the SNMP mid-span product, which provides telemetry of power consumption of the device. With this information, one can calculate the exact amount of power consumed by the network in case of power failure, and adapt the size of the UPS accordingly. This tool enables an exact measurement of power consumption and allows the installer to purchase the appropriate UPS. The managed version of the mid-span enables the user to define a power threshold. This capability offers a tool, which can be used to locate any deviation from the predefined level of power consumption by presenting a trap. 9

5.2. Select a high-availability UPS technology There are two major technologies for UPS systems. While Line Interactive UPSs protect your equipments and sensitive applications against the most common power quality problems at an attractive cost, only On Line Double Conversion UPSs ensures highest quality output against all power issues. With On Line Double Conversion UPSs, input AC is permanently regenerated without draining the batteries for high isolation from AC utility noise. All transfers to or from battery back up mode are completely undetectable and uninterrupted. An automatic failsafe and overload bypass is provided during extreme conditions if the UPS is no longer able to perform its task to ensure fault tolerance operation. This type of availability is often a requirement in Voice over IP installation, to reach the same type of availability as exist in traditional circuit-switched telephone systems. Some of the benefits of On Line Double Conversion UPSs are : Ultimate Voltage Regulation - Constant voltage regulation is one of the exclusive benefits of MGE On Line UPSs, ensuring a steady and precise voltage flow. This is the main difference with Line Interactive UPS designs, where output voltage will actually fluctuate within a much larger window. Another benefit of Double Conversion On Line UPSs is their ability to operate in extremely low line conditions (down to 150 volts input while still delivering 230 Volts in output to protected equipment) without draining their batteries. Genset compatibility - More and more customers combine the power quality provided by a UPS with the unlimited backup time of a generator. On startup, these devices may generate frequency fluctuations that some UPSs will not tolerate. Double Conversion MGE UPSs have been designed for full genset compatibility. 5.3. Assess backup time needed For selecting a UPS system, it is also important to consider for how long the installation should be able to sustain a power outage. For Voice over IP applications typical customers need range between ½ hour to 4 hours of backup time, and sometimes more. This leads to UPS configurations with long autonomies. MGE UPS Systems offers a full range of battery extensions and special long autonomies battery chargers, that also fit in the convenient 19-inches rack format. For details on configurations, please refer to MGE or use MGE s on-line UPS selector at : http://www.mgeups.com/selector/ups/ 5.4. Ensure graceful wiring/edge closet integration Often the wiring /edge closets have not been designed to accomodate much equipment. It is important to consider easy integration of the UPSs in the 19 inches racks present in the wiring closet. As many UPSs are optimized for deep servers racks and not for shorter internetworking equipment, they may not fit in wiring closets racks. MGE s Pulsar Extreme and Comet Extreme, for instance, have been designed for networking and telecommunication racks and are only 462mm deep. Also, for maximum uptime, it is important to consider serviceability questions such as : can I easily perform the maintenance of my UPS s (battery replacements, etc.) without disconnecting the loads? Features such as the manual maintenance by-pass of MGE s Pulsar and Comet Extreme series greatly help to that end. 10

5.5. Look for remote management capabilities As UPS equipments will be most of the time hidden and far away from the administrator in the switch closets, it is important to look for UPS solutions that are remotely manageable. Depending on the size of the company and its network management policies, different options are available : remote management of the UPS through SNMP or XML via a web browser, integration of the UPS installed base within the company s Network Management System (NMS), such as HP Openview, IBM Tivoli or Computer Associates Unicenter. In all cases, look for seamless integration of a network interface in the UPS and availability of the adequate interface software components (see under for more details). 6. Remote management As distribution and edge network equipment are scattered around the buildings or the floors within the enterprise, it is very important that they are remotely manageable using industry-standard tools. 6.1. On the PoE mid-span side : A unique option of PowerDsine's Power over Ethernet mid-spans is web-based SNMP remote management. This feature allows for remote control of the mid-span technology and the gathering of essential telemetry, collected by the units. Remote management provides an immediate alert and response to changes in the IP Phones in the field, and enables to remotely reset devices. Main features of remote management: Telemetry of IP Phones status and presence -The remote management feature will alert to a change in the status of the IP Phone such as fall in power consumption, disappearance and malfunction. Telemetry of power consumption - Collects power consumption information, to measure appropriate size of UPS for your network, saving the cost of needless UPS capacity. Power-off IP Phones to save costs - At times it may be desirable to power off selected IP Phones when not in use, such as over the weekend and holidays. This helps cost conscious enterprises and ensures the ultimate amount of security when the phone is not to be used. 6.2. On the UPS side : MGE UPS s are all remotely manageable either through SNMP, which allows seamless integration of the UPS s within standard Network Management Systems (NMS) platforms, or through XML technology that allows to securely, remotely access the UPS s embedded web server via any web browser on the network. In a Voice over IP environment, the following features are desirable : Interface with the enterprise standards MGE UPSs can be fitted with an internal network interface card, that both supports the SNMP protocol, and includes and embedded web server for web-based management Remote administration From a remote computer anywhere on the network, you can through an intuitive graphical interface, monitor UPS parameters such as battery levels, power quality, state of the UPS, receive alerts, etc. Automatic actions upon specific events you can program event notifications via e-mail, SMS/pager, program actions when battery levels are low such as system shutdowns etc. Easy integration in your company NMS platform UPS can be discovered, mapped and managed via standard platforms such as HP Openview, IBM Tivoli or Computer Associates Unicenter. 11

7. Fit to other «Edge» Network Applications Although this paper focuses on the Voice over IP application in particular, much of what it describes, also applies to a host of new applications that can greatly benefit from the Power over Ethernet technology and the centralized UPS protection that this allows. Among these, one can cite : Wireless LANs Together with Voice over IP, wireless LANs are one of the fastest growing segments in the networks market. Wireless LAN access points are low-power devices that are also connected to the edge closet switches and require low DC power. For such application, Power over Ethernet technology is of great benefit, because it dramatically simplifies the cabling problem (get rid of the low power DC power cable to each access point). This is why Power over Ethernet is one of the most demanded features for access points products and most suppliers already support this standard. In many cases, wireless LANs are also mission critical and can benefit from the centralized protection against power losses, provided by a UPS located at the switch closet level. Consider, for instance, the deployment of a «hot spot» in a public place (airport..) or a hotel. Customers will expect a high quality service from this infrastructure and will require uptime for this service, in the range of what they are used for with telecommunications services, especially if they have paid a fee for it. Security devices More and more security devices (network cameras, access control devices, ) are also designed to the IP standard to easy connect and be monitored through the Enterprise IP network. Such low power devices also tend to be more and more powered through the Power over Ethernet technology through the Ethernet cable. Needless to say, availability of such devices in case of a power failure is in most cases, an absolute requirement. 12

Summary and conclusions The emergence of a new standard, IEEE 802.3af or «Power over Ethernet», is changing the way we think about powering network components. It is now possible to power, from a central point located at the distribution/edge switch, a number of network devices through the same standard cable that is used for data communication, and that is already installed in most enterprises. This comes at the time when a series of new network applications and devices can greatly benefit from such technology. It is extremely convenient, cost effective, easy to manage and reliable to power network devices such as IP phones (but also, wireless access points, and IP-based security devices such as IP cameras), through such an architecture. This is why all network vendors are targetting these new, fast growing applications, have endorsed the 802.3af standard. Most of them are now shipping networking equipment supporting PoE, mostly, through using PowerDsine components. Using PowerDsine Power over Ethernet products for IP Telephony, and MGE UPS Systems power protection devices, IT and facility managers and users will get the same level of availability from their VoIP architecture as they experience with the traditional circuit switched telephony systems. For more information on the PowerDsine Power over Ethernet mid-span products and additional 802.3af compliant products, as well as the IEEE 802.3af standard for DTE Power via MDI, look us up at: www.powerdsine.com For more information on MGE s complete range of UPS systems and high availability power solutions, look us up at: www.mgeups.com 13

Appendix 1 The Basics of Enterprise IP networks how is an enterprise network structured? Enterprise IP networks are typically built in three to four layers. 1 st layer : «core» networking equipments An enterprise is connected to the Internet through a variety of networking and telecommunication equipments, including high-end «core» routers and switches. These equipments are typically located in a special room, often called the Point of Presence (POP) room or Main Distribution Facility (MDF) room. This room can be shared with other IT or telephony equipment, or be a distinct facility in the enterprise. However, it is always closely connected to the computer room or data center of the company, through high-speed networking connections. The equipment present in this layer, are typically stored in 19-inches racks that can draw 1 to 3KW 220V or 208V AC power. These racks tend to be shorter in depth than server or other IT equipments racks (600mm or less, vs. 800mm or more for servers). Figure 7 : Enterprise IP Network, Campus Environment 2 nd and 3 rd layer : «distribution» and «edge» switches To these core networking equipments, are connected high-speed fiber optics links that run through the floors or the different buildings of the enterprise campus (it is called the enterprise network «backbone»). This backbone is then distributed through either one or two levels of switches ensuring the distribution of this network through the company. In the case where there are two levels of switching equipment, the first one (closer to the core) is called «distribution» layer and the second one is called «edge» or «access» layer. In both cases, these switches are stored in 19-inches racks, that are fitted in «wiring closets» (or «telecommunication closets» as they often share space with traditional telephony patch panels). In these racks one finds ethernet switches, often stacked, and patch panels, that are used to conveniently change the patching configuration to evolving user requirements or floor distribution changes. 14

As above, because of space constraints in these wiring closets and because internetworking equipments manufacturers have standardized on relatively low depth equipments, these racks are often 600mm deep or less. Until recently, these switches tend to draw modest power (100-200W of 110V or 220V AC). Also, because most mission-critical data resides on servers in secured computer rooms or data centers, in many cases, these wiring closets have not been protected against power loss through the use of uninterruptible power supplies (UPS) systems. Things are changing, because the network is being used more and more for mission-critical applications such as voice over IP or security. To this end, the combination of Power over Ethernet technology and UPS systems, allows a very convenient, simple architecture to safely power not only the internet switches, but also, the low-power devices connected to them such as VoIP phones, security devices (cameras on IP ) or wireless access points. This, as we will see later, this increases significantly the power requirements within the edge wiring closets. 4 th layer : Workgroups and IP devices To the edge switches, are connected the LAN (Local Area Network) components (workgroup servers, PC s, workstations, printers, etc.). (In fact, the role of the switch is to connect but also isolate the LAN traffic from the rest of the enterprise network to increase the overall network performance.) The connection from the edge switches is done via patch panels and a series of «twisted pairs» copper cables -often called «category 5» or «category 6» cables. Figure 8 : Enterprise IP Network, LAN/Workgroup Environment Until recently, only relatively high-power devices such as PC s, workgroup servers and printers were connected to the LAN. These devices require 50 to 300W and need to be powered through a local 110V or 22OV AC outlet, so, there was no need to carry any power through the cat5 or cat6 network cables (unlike what exists on traditional telephony cables). With the development of the new «smart» connected devices mentioned above (that use only 10W or so of DC power) it is has become very convenient to power these -and protect them against power failure- via the ethernet cables, from a central place : the edge wiring/switches closets. 15

Appendix 2 Types of IP Telephony Installations There are different types of IP Telephony installations, which vary in the following parameters: 1. Infrastructure type - VolP system can be installed in a legacy infrastructure, using the existing Ethernet Switches and cabling infrastructure or in a totally new environment (Greenfield installation). 2. VolP PBX - The PBX can be IP enabled PBX or Pure LAN PBX. IP Enabled PBX are been offered by the traditional PBX vendors by accommodating a range of IP-oriented components-voice over IP trunks and gateways, IP Iine and station cards, IP telephones, etc.-in order to IP-enable existing circuit switched telephony systems. Pure LAN PBX is based solely on IP Packets routing. 3. Installation size - Number of IP Phones installed 4. Variety of end terminals in the installation - Different types of terminals can be installed in a LAN infrastructure, such as wireless LAN access points, network cameras and security devices. These parameters affect the type of Power over Ethernet solution which best suit the installation. The following lists a few examples of VolP installations and the appropriate Power over Ethernet solution: Pilot installation - ln a VolP pilot installation, a small amount of IP Phones are installed first, typically 20 to 30 IP Phones. This enables the company to carefully examine the performance of the new PBX system, in parallel to the existing circuit switched PBX. The full deployment is graduai, usually done in stages and may take between one month to two years. This type of installation can be seen in medium to large enterprises, with over 100 workers, in which the enterprise is moving locations or upgrading voice/data needs to address specific application requirements. Power over Ethernet mid-span solutions best fits this type of installation as it enables the user to examine the VolP system with minimum changes in the infrastructure, i.e. with no need to replace the existing Ethernet Switch, add Ethernet points and power outlets near the desktops to provide data and power to the IP phones. Greenfield installation - Greenfield installations are usually implemented in new buildings or new site locations with no existing voice and data infrastructure. ln this type of installation, new Ethernet Switches should be installed as part of the infrastructure deployment. ln this event, the appropriate Power over Ethernet solution is end-span, i.e. integrated in the Ethernet Switch. However, when choosing an end-span solution, it is highly recommended to verity that the Switch is IEEE 802.3af compliant. Enterprises will be best served by an infrastructure that continues to support an open, multiservice environment, which does not limit the customer to implement proprietary terminais of one vendor only. Hybrid VolP installation - ln this type of installation, IP components are added to the traditional circuit switched PBX without changing the existing infrastructure. As a result, the environment includes a mix of analog, digital and VolP phones. For these installations, Power over Ethernet plug and play Mid-spans offer the ideal solution. It provides the IP Phone handsets a reliable powering solution without replacing the Ethernet Switches with ones that provide in-line power. The Mid-span solution also offers a future expansion opportunity, by adding more Midspans to the network if needed. Small or spread installation - Enterprises with multiple site locations and remote offices, often evaluate the adoption of IP telephony solutions. They can benefit from economies of scale by having a single voice application at a central location, serving multiple remote office locations. This can be hosted in the enterprise's own network or that of a network service provider. This design limits the quantity of telephony hardware deployed in branch offices, keeping capital costs and administration to a minimum. Low-port density Mid-span products provide a cost effective powering solution which best fits this approach. Highly sensitive installations - There are few market segments, which can be identified as highly sensitive to down time, for example cali centers, brokerage houses and production lines. As a result, when installing VolP system in such sites, multiple backup systems are installed to assure full operation 100% of the time. ln this case, the appropriate Power over Ethernet mid-span solution must include both AC and DC input power, to ensure 100% availability and full back up to the network. 16

About PowerDsine PowerDsine - Powering Converged Networks PowerDsine Inc. is a leading designer and developer of software-controlled power solutions, which enable the delivery of operating power over converged voice-data communications and telecom networks. PowerDsine is the market leader of Power over EthernetEthernet, a revolutionary technology that integrates data, voice and power on standard Ethernet infrastructure. As one of the founding members of the IEEE 802.3af Task Force, PowerDsine is at the forefront of setting the global standard for remotely powering Ethernet devices over LAN infrastructure. Since Power over EthernetEthernet introduction to the market in 1998, PowerDsine has already established business relationships with leading major communications giants worldwide. PowerDsine LTD. 1 Hanagar St. Hod Hasharon 45421, Israel Tel: +972-9-775-5100 Fax: +972-9-775-5111 E-mail: techsupport@powerdsine.com Web : www.powerdsine.com About MGE UPS SYSTEMS MGE UPS SYSTEMS is a world leader in providing high quality power solutions that increase power availability and system uptime to PCs and enterprise-wide networks, mission -critical telecommunication systems, and industrial/manufacturing processes. MGE's comprehensive product offering includes Uninterruptible Power Supplies (UPSs), inverters, rectifiers, power management software, active harmonic conditioners, and surge suppressors that provide MGE's customers with end-to-end infrastructure solutions. With its Total Quality Management and PowerServices programs, supported by a network of 900 service specialists in 170 centers worldwide, MGE's customers are assured of the highest-level of quality and service throughout the complete life-cycle of their installations.with international headquarters in Grenoble, France and 37 subsidiaries in another 100 countries, MGE is able to deliver the latest in innovative solutions around-the-globe. MGE UPS SYSTEMS 140 Avenue Jean Kuntzmann ZIRST Montbonnot 38 334 Saint Ismier France Tel: 33 (0)4 76 18 30 00 Fax: 33 (0)4 76 18 40 00 Web : www.mgeups.com 17