ip mobility: raising the bar for convergence networks · 2009. 9. 3. · 3 ip mobility: raising the...

WHITE PAPER

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Introduction

Analysts predict that the explosive growthin enterprise wireless communications seenduring the past few years will continue.

• By 2006 the number of mobile workers inthe U.S. will reach 105 million—66 percentof all workers, according to IDC1.

• 50 percent of enterprises will have wirelesse-mail in place within three years, whichaccording to Meta Group2 will help triggera surge of wireless application projectsduring that time.

• Gartner3 estimates that by 2010, 80 percentof key business processes will involveexchange of real-time information amongmobile workers.

• Meta Group4 predicts that by 2005, 95percent of corporate laptops will ship withmobility capabilities. As a result, wirelessconnectivity within the enterprise willbecome the norm, “whether or not thebusiness is ready.”

Growth in mobility within enterprises hasbeen a grass-roots phenomenon largelydriven by end users and the requirementsof fast-evolving IP networks. In fact, someenterprises have wireless infrastructuresthat were deployed entirely by end usersindependent of the IT group. Gartneranalysts estimate that one in five companieshas a wireless LAN (WLAN) that the CIOdoesn’t even know about.

The good news is that many enterprisesnow recognize that they need to supportmobile devices and enhanced mobility

within and beyond their premises.Enterprises in healthcare, government,education, and high-technology industrieswith sizable campuses and large populationsof mobile workers are proactively deployingmanaged wireless enterprise infrastructurescomprising wireless access points and wire-less switching that permit roaming.

While IP-based mobility has been enjoyingsignificant growth, enterprises are alsodeploying IP-based convergence applica-tions at an accelerated pace. IP telephonyand related technologies have gained groundmainly due to the maturity and robustnessof enterprise IP networks and the Internet.Sophisticated convergence applications suchas unified messaging, conferencing, andinstant messaging have enjoyed significantgrowth, as have convergence services suchas presence and standards-based end-userclients such as IP phones.

The confluence of IP-based mobility,convergence applications, and feature-richmobile devices offers exciting new oppor-tunities for enterprises. They can enhancetheir end-users’ productivity and theircustomer service levels at a much lower costthan is possible with conventional enterprisemobile telephony solutions based on time-division multiplexing (TDM) technologies.

3Com, as a leader in IP communications andenterprise network infrastructure, includingIP-based LANs and WANs, wireless networks,and IP convergence applications, is thereforein a unique position to take convergence tothe next level: mobility.

IP Mobility:Raising the Bar for Convergence Networks

C O N T E N T S

Introduction....................................................1

3Com’s Vision for IP Mobility ..........................2

Requirements and Challengesof Enterprise Mobility .....................................3

3Com Convergence Architecture to Enable Enterprise Mobility ..........................3

3Com SIP-Capable Firewalls to Enable Tethered IP Mobility.............................5

3Com Wireless Infrastructure to Enable Secure and Non-disruptive Roaming ...............6

3Com Client Software to Enable Mobile Access Convergence Applications .......9

3Com Convergence Services to Enable IP Mobility Across Public Domains .......9

Summary ......................................................10

1 “Managing the Mobility Imperative: Enterprises Embrace Mobility Strategies to Achieve Competitive Advantage”, 2004 2 “Wireless E-Mail: TCO Versus ROI: Part 1”, October 6, 2004, Report # Delta 3083 “Enterprises Must Assess Impact of Mobile Applications”, December 22, 2003 Report #DF-21-43744 “How to Succeed in Mobile Initiatives”, January 6, 2004 Report # Practice 2146

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Corporate Location Corporate Location

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Internet

IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS

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Mobility is the ability to roam and still beaccessible to other network users. However,mobility is sometimes regarded as pertainingonly to cellular networks. According to thisnarrow definition, an enterprise user whomoves between several different corporateand external locations has to resort to theuse of a cell phone regardless of whether atethered office phone or an enterprise wire-less network is available.

Cellular mobility can be quite expensive andsound quality can be poor due to patchycoverage in enterprise locations. Typicalcellular devices also lack access to sophisti-cated convergence applications such as datasharing. In addition, cellular mobility requiresusers to have multiple phone numbers: one forthe office phone, one for the cell phone, andone for the home phone. Customers have toremember multiple numbers to reach anenterprise user, or resort to calling the numberthat represents the most expensive option—the cell phone.

3Com takes a broader approach to mobility byconsidering the types of networks to which auser may be connected at various times of day,and the availability of cellular infrastructureor cost-effective alternative infrastructure suchas enterprise networks at any given location.As shown below, an enterprise user may beat any one of several possible locations:

• At a desk with a tethered desktop phone

• In a corporate office conference room withaccess to a tethered phone

• Roaming within the corporate location

• Driving between corporate locations, orelsewhere

• Visiting a corporate location with access to a workspace having a tethered desktopphone or a mobile phone on the convergedenterprise network

• At a hotel with PSTN or Internet connectivity

• At home with access to a home phone

3Com’s vision is to provide seamless mobilityby allowing users to leverage all the cost-effective alternatives available to them at anyparticular place or time. 3Com’s strategy isto deliver this mobility in three dimensions:

Physical Mobility. The user is able to movebetween networks, connecting and recon-necting using the most cost-effective networkoption available. Such options include enter-prise LAN, enterprise WAN, wireless LAN,the Internet, and public switched telephonenetwork (PSTN). 3Com’s approach deliversmobility at a small fraction of the cost ofconventional mobility delivered throughcellular networks.

Identity Portability. The user is able to roamwithin multiple network infrastructures andacross network infrastructure boundarieswhile retaining a single identity. The power of3Com’s approach is that the user is reachablevia one access method—such as a single phonenumber—by customers, colleagues, partners,and friends regardless of which network theuser is connected to and where the user islocated. Even if an employee should leavethe organization, continuity with customersand partners can be maintained through thisidentity which can be transferred to areplacement employee.

User Interface Universality. The user is able totake advantage of all the services and appli-cations that he or she is authorized to accessby means of various devices (desktop phone,desktop computer, wireless device). The userenjoys the same services and appears thesame way (presence) to other users no matterhow the user is connected to the network.

3Com’s Vision for IP Mobility

Mobility in Multiple Dimensions

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Requirements and Challengesof Enterprise Mobility

To realize the promise of universal network mobility, several challenges must be overcome.

Security When users are mobile, connections and data need to cross multiple networkboundaries, each of which poses a security threat. Wireless networks present uniquethreats because rogue users can enter the enterprise network through wirelessaccess points that may not be sufficiently protected as part of IT security protocols.Providing authenticated access to the wireless network and convergence applicationresources through the wireless domain are important requirements to consider whenenabling enterprise mobility.

Roaming Roaming implies crossing one network boundary and entering another while maintaining communication. Roaming occurs within the enterprise wireless LANwhen a user crosses from the user’s IP subnet to another. Such roaming can causedisruption, especially in connection-oriented real-time communications such as voiceconversations. Maintaining continuous connections and consistent access privilegesduring switchovers and hand-offs among the wireless networks is essential for enablingconvergence applications in enterprise wireless LANs.

Devices Mobility is enabled by remote tethered devices such as IP phones and handhelddevices used by roaming users. These devices communicate with other devices andoffer access to convergence applications. Conventional mobile devices cannot accessall convergence applications, which may include presence-based conferencing anddata sharing. In order to achieve universal IP mobility, mobility devices must have thecapability to access all the convergence applications deployed by the enterprise.

Portability In conventional networks, callers often have to try multiple numbers in order toreach the called party directly. It is much more convenient for callers to access thecalled user with one enterprise number, which is automatically inherited by any ofthe devices that the user might employ. Such inheritance enables the consistentappearance—including presence availability—of mobile users to the other uses.

3Com® ConvergenceArchitecture to EnableEnterprise Mobility

As shown below, 3Com employs a standards-based, layered architecture for delivering a suiteof convergence applications.

3Com IP Telephony

Module

3Com Convergence Center Client

3Com® Gateway

3Com IP Phone

Wireless SIP Device

3Com IP Conferencing Module

3Com Contact Center Module

3Com IP Messaging Module

3Com Presence Module

3Com Wireless Access Points and

Switches 3Com Switches, Routers, and Firewalls


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Key Aspects of 3ComConvergence Architecture1. The communications infrastructure is based

on the Internet Protocol (IP). This layeruses all the standard components of IPnetworks, such as IP routers and switchesthat provide connectivity, virtual LANsand subnet routing, Domain Name System(DNS), and Dynamic Host Control Protocol(DHCP). The higher layers are abstractedfrom additions and changes to thecommunications infrastructure.

2. Communication services—includingname/address resolution, location services,authentication, session establishment,presence, privacy, redirection, andforwarding—are provided by IETF-specified Session Initiation Protocol (SIP).SIP offers several advantages for enabling3Com® convergence applications using anIP infrastructure.

SIP uses existing Internet technologies such as DNS for name resolution, URLsfor naming, and HTTP and MultipurposeInternet Mail Extensions (MIME) forcontent packaging and transport. Withthese capabilities, SIP not only integrateswith Internet technologies, it also allowsdevelopment of applications usingpopular web technologies and interfaces.

True mobility requires identity portability,including consistent appearance andpresence. SIP standards specify severalcapabilities—including registration,authentication, and presence—whichinherently support mobility. 3Com SIPimplementation is based on a service-oriented architecture (SOA) that deliversthese capabilities network-wide. Thearchitecture allows services to be deployedanywhere in the enterprise network.Convergence clients such as IP phones,soft phones, and SIP-compliant mobiledevices, as well as convergence applicationssuch as IP telephony, can access thesecapabilities by invoking the appropriateSIP-based service across the network.

The 3Com architecture also allows theservices to be located and administeredcentrally5, while the services are availableto every client and application across thenetwork in a global manner. Using thisservices-oriented architecture, the 3ComSIP-based communication services layerdelivers key services that are critical to IP

mobility. These include:

• A standards-based authentication andregistration service through which aname with its IP address (or URL) can be registered dynamically.

• 3Com leverages this capability to enableusers to log in their identity (e.g. phonenumbers) at communication devicesother than their desk phones, enablingusers to receive calls made to their deskphone numbers at locations other thantheir desks, such as remote offices,hotels, and home offices.

• The ability of multiple devices such astelephones to receive connections (calls)simultaneously and complete the callwith the device that responds first.

• 3Com leverages this capability to enableidentity portability to multiple devices andmultiple locations, enhancing mobilityfor traveling and work-at-home users.

• Notification to the presence server ofthe presence and availability (presencestate) of compliant (SIP) clients.

• The server “publishes” the presence stateto all the other subscribing clients, lettingeach user know when another user isavailable on the network—even if theuser is mobile—so that the user can beincluded in a call or ad hoc conference.

3. 3Com offers a suite of applications thatleverage the SIP-based communicationsservice platform. Convergence applicationmodules include IP Telephony, IPMessaging, IP Conferencing, and IPContact Center. As a result of abstractingthese applications from the communicationslayer through IP and SIP-based communi-cations services, these applications arenot dependent on a particular type ofnetwork infrastructure. They run equallywell on an enterprise IP, wireless LAN, or public Internet service infrastructure.All the convergence services and applica-tions are delivered to SIP-capable clients.In addition, the 3Com ConvergenceApplications Suite offers a complete arrayof voice-over- IP (VoIP) gateways to bringnon-SIP devices such as analog phonesinto the SIP world.

4. While conventional telephony devicescan access most of the convergence appli-cations, including IP Telephony, IPMessaging, and IP Conferencing, certain

5 Note that the services may also be optionally administered locally in each enterprise location, or in regional enterprise locations.

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As just indicated, 3Com SIP-based convergencearchitecture allows portability of users’ identityto different devices and mobility from onedevice to another. These capabilities are usefulin a variety of scenarios such as the following:

• An enterprise user traveling to a differentcorporate location, even an internationallocation, can log his or her identity (e.g.telephone number) to a temporary devicethat can receive or place calls.

• An enterprise user staying at a hotel canconnect to the enterprise network and logan identity using a convergence centerclient to receive or place calls.

• An enterprise user working at home canconnect to the enterprise network, log inthrough an IP phone or convergencecenter client, and receive or place calls.

The first scenario is enabled by authenticationand registration (note that this is commonlyknown as registrar in SIP parlance) servicesprovided by the 3Com communications serviceslayer. In addition to the authentication andregistration services, the latter two scenariosrequire a secure infrastructure to enableremote communications with a mobile user.

The conventional way to provide remoteaccess for mobility is to use virtual privatenetworks (VPNs). VPNs offer authenticatedand encrypted access to the enterprisenetwork, so the user is virtually inside theenterprise network and has access to all ofthe enterprise resources that the user wouldnormally access while on site. Because VPNsconsume significant processing and networkresources, encrypt data, and expose all theresources within the enterprise network to theVPN user, they are typically reserved for on-demand access to business applications andfor infrequent and short-duration connectivity.

Enterprises that want to offer Internetconnectivity to convergence applicationsrather than the entire enterprise application

suite, long-duration connections, andfrequent connectivity (such as access to IPtelephony from home) require a more scalableand cost-effective solution than a conventionalVPN can provide.

A more appropriate solution is to access theconvergence applications without VPNs andrestrict such connections to the enterpriseconvergence suite whenever the Internetconnection is available. However, direct accessfor Internet-based clients and SIP devices tothe enterprise network is prohibited in mostenterprises, since firewalls are typicallyconfigured to block traffic that attempts toopen ports and enter the network. Trafficfrom outside the corporation is generallyrestricted to a few selected addresses and afew selected ports that are not widely publi-cized. The rest of the traffic is restricted toresources in the DMZ.

As a result, remote users who inherit dynamicaddresses through DHCP cannot connect toconvergence applications located inside thecorporate network, including IP telephonyservices. Yet opening up the firewall forconvergence application traffic is tantamountto an open invitation for denial-of-serviceattacks and infiltration of the corporatenetwork by hackers.

To solve this security issue, 3Com offers aSIP-capable firewall. As shown in the figureon the following page, a SIP firewall residesat the border of the enterprise network andmonitors VoIP signaling protocols such asSIP registration and session establishmentarriving from the Internet. It intelligentlyassigns and memorizes end-point addressesso they can be used statefully for real-timetraffic within the context of a session. TheSIP firewall also acts as a SIP proxy whileenabling SIP sessions through the firewall,executing the following steps:

1. SIP signaling comes in on a dedicatedport (usually 5060) at the firewall.

services provided by 3Com convergenceapplications require a rich user interface.For example, 3Com IP conferencingprovides a data sharing capability thatallows two users in conference to haveshared access to each other’s screens,desktop applications, or files. This type of service requires a user interface that is

beyond the capabilities of conventionaltelephony devices. To enable access tosuch application services, 3Com offersConvergence Center Client software thatcan be ported to a variety of clientdevices, including software-download-able IP phones, mobile SIP devices, anddesktop and laptop computers.

3Com SIP-Capable Firewallsto Enable Tethered IP Mobility

Most enterprise networks are optimized forusers who work at fixed locations. Such staticoptimizations are achieved by configuring theuser as a part of a virtual LAN or IP subnet.In addition, user privileges are configuredinto access control lists (ACL) on router andswitch ports in fixed locations such as wiringclosets and the data center. As users roamthrough wireless LANs, they will come withinthe radio coverage of an access point that isattached to a different port on a differentswitch and router subnet than their homesubnet (subnet on which they are configured),VLAN, or router and switch ports. Thiscreates challenges in terms of security anddisruption to continuous communication.

As part of the 3Com Wireless LAN MobilitySystem, 3Com offers wireless LAN switcheswith 3Com Wireless Switch Manager softwareto centrally manage and control 3Com wirelessLAN Managed Access Points (MAPs). Theswitch manager enables central MAP config-uration and optimization of radio-frequency(RF) coverage and performance. These wire-less solutions help secure the enterprise

network from intruders while providingcontinuous communications.

Secure Access to Network Services. Rogueaccess points and rogue users are a majorsecurity concern in enterprise wireless LANs. It is not uncommon for enterprise users tointroduce access points inside the networkthat are not authorized by IT. Methods ofcontrolling unauthorized access includesweeping the enterprise manually to detectrogue access points, and using packet sniffersto analyze Layer 1 and Layer 2 informationto detect packets transmitted by rogue accesspoints. 3Com Wireless Switch Manager soft-ware provides scheduled or on-demand RFscans to identify unauthorized access pointsand ad-hoc networks. It then alerts thecentral IT staff of anomaly in the network.Dedicated access points can continuallysweep the airspace for 24/7 protection inenvironments that require rigorous security.

3Com also recognizes that controlling rogueaccess points alone is not sufficient foroptimum security. Sometimes, it is the rogue


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2. The SIP registrar (registration service) isconsulted to determine the private addressat which the recipient is located, and thesignaling is passed on to the recipient.

3. Once the two clients have agreement thatthey want to set up a session, the firewalldynamically opens UDP ports, with theport numbers agreed upon during setup.

4. The firewall allows media traffic throughthe ports opened during the session.

SIP firewalls offer the following benefits:

• Protection of convergence applicationsfrom intruders and denial-of-serviceattackers at the firewall

• Control of call admission into the IPtelephony system

• Concealment of the internal address spacefrom the public Internet

• Support of VoIP-optimized and VoIP-protocol-cognizant network addresstranslation services

3Com Wireless Infrastructureto Enable Secure and Non-disruptive Roaming

Internet

Main Office

Telecommuter

Enterprise IP Network

3Com IP Telephony Module Server

SIP Firewall

3Com Convergence Center Client

3Com® Gateway

Legacy Phone

3Com IP Phone

3Com IP Conferencing Module

3Com Contact Center Module

3Com IP Messaging Module

3Com Presence Module

SIP-Capable Firewall for Secure IP Mobility

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user who represents a security threat andthe rogue access point is merely one of theenablers. A rogue user may use several tech-niques, including spoofing MAC address, togain access to the corporate resources, evenif the rogue access points are detected andeliminated. Therefore, controlling rogueaccess at the user level is just as important as discovering rouge equipment.

Another security concern is that user ACLsand permissions are typically configured as apart of a subnet according to wired IP networkbest practices. In order for roaming users to getaccess to the network resources as they roamon a wireless LAN, network permissions basedon ACLs need to follow users as they roam.Without this capability, roaming users will bedenied service at various segments of theenterprise wireless LANs.

To ward off rogue users and limit wirelessnetwork and network resource access tolegitimate users, 3Com wireless LAN switchesoffer Identity-Based Networking™. Thisinnovative capability delivers network servicesbased on user identity instead of ports ordevices. In convergence applications, 3ComSIP implementation performs authenticationof users based on their IDs (such as phonenumber or URL). The same ID may be usedby the wireless LAN switch to authenticatethe user.

During the authentication process, the systemlearns each user’s network authorizationattributes such as VLAN/subnet membership,ACLs, and Mobility Profiles which may limitwhere the user is allowed to roam. Multiplewireless LAN switches may be grouped into aMobility Domain™ to share user profiles anddatabases, supporting mobility and security

across the entire network infrastructure—including remote offices. The wireless LANswitches that form the Mobility Domainauthenticate each user and enforce theirnetwork authorizations wherever they roambased on a single sign-on.

3Com Wireless Switch Manager softwarealso monitors RF signal strengths from eachuser and ascertains the location of the userrelative to the enterprise floor plans basedon signal strengths and radio coverage of theaccess points. Using this capability, theswitch manager can locate rogue users andprevent rogue access.

Subnet Roaming. Subnet roaming occurswhen the user roams to an access pointhosted by a wireless LAN switch whosenetwork port is not directly connected tothe roaming user’s VLAN/subnet. Mobiledevices involved in live communications,such as mobile SIP phones, may inherit IPaddresses of different subnets and sufferdisruption of communications, conversations,and connections. To prevent such disruptions,the 3Com Wireless LAN Mobility Systemsupports subnet roaming with Identity-BasedNetworking that allows the Mobility Systemto enforce network authorizations based onthe user’s identity, even when the user roamsacross subnets. In addition, Identity-BasedNetworking provides seamless, non-disruptiveswitchover from one IP subnet or VLAN toanother while the user is roaming betweensubnets. As users roam, the mobility systemsallow the user to roam from one wirelessLAN switch to another by leveraging Layer 2tunneling technology.

To illustrate the ability of the 3Com WirelessLAN Mobility System to provide seamless

Building 1

IP Tunnel

132.2.1.0 132.2.3.0 132.2.8.0

Doctor's Office

NurseBuilding 2

Hospital Campus Using the 3Com Wireless Mobility Solution

and continuous connectivity during subnetroaming, consider the real-world healthcarescenario shown in the diagram on page 7.

• A nurse looking for a doctor would typicallycall the number assigned to the doctor’soffice phone at the doctor’s desk.

• If the doctor is in the vicinity of his or heroffice but roaming with a wireless devicein the same subnet as the office (subnet132.2.1.0), the doctor would be reachablethrough the wireless LAN. If the doctor isusing a SIP-compliant mobile IP device andis authenticated with the office number onthe wireless SIP device, the call would beautomatically routed by the 3Com SIP-based IP telephony server to the doctor’smobile device in the 132.2.1.0 subnet.

• Consider that the nurse is informing thedoctor that a patient needs the doctor’sattention in another part of the hospital,which is covered by a different set of wireless switch and access points andconnected to a different subnet (subnet132.2.3.0), shown in the precedingdiagram in the lower right of Building 1.

• While the doctor is walking to the patient’ssubnet area, the nurse provides the patient’shistory. While in conversation with thenurse, the doctor roams into this othersubnet and comes within the radio coverageof a wireless LAN switch in this subnet.

• The wireless LAN switch that detects thedoctor’s identity automatically searches itslocal Mobility Domain database of wirelessLAN switches to find the home (where thedoctor is permanently configured) wirelessLAN switch, whose network port is directlyattached to the doctor’s office VLAN/subnet.Once the home wireless LAN switch isfound, the wireless LAN switch hosting theroaming doctor establishes an IP tunnel tothe home switch and forwards the doctor’sconversation to that switch. The homeswitch, in turn, forwards the traffic overthe SIP session that is already in progresswith the nurse.

• After visiting the patient, the doctor roamsto another building, located in a differentsubnet (132.2.8.0) within the hospitalcampus to consult with a specialist aboutthe patient. When the doctor comes withinthe coverage of another visited wireless LANswitch located in the remote building, thatswitch performs the task of locating thehome switch of the doctor and establishingan IP tunnel with the home switch.

• If the nurse calls the doctor about anotherpatient, the call is automatically routedfrom the home switch through the IPtunnel to the visited switch located in theremote building.

This scenario is applicable in several types ofenvironments, including airports, educationalinstitutions, and businesses with largecampuses and multiple offices.

Since the process of locating the home switchand establishing a tunnel may result inunnecessary delay and processing, 3Comwireless LAN switches multiplex multipleusers’ traffic on an existing tunnel, if one hasalready been established to support anothersession between the visited switch and thehome switch of the user. If the roaming useris in the same subnet as the user with whomhe or she is communicating and they are bothwithin the coverage of the same wireless LANswitch, the switch short-circuits the tunnelsto and from the roaming user’s home switch,and switches the traffic locally withouthopping multiple tunnels.

In summary, 3Com mobility solutions, togetherwith 3Com convergence applications, offerthree key benefits for roaming users:

1. Regardless of the subnet in which the user(mobile client) is defined and where theuser is roaming, the client always has thesame IP address.

2. Regardless of the access point with whichthe mobile client is associated, the wirelessswitch that controls the access point forwardsthe traffic to the appropriate wireless switchat which the client is defined. This switch,in turn delivers the traffic to the appropriateend point or application.

3. Independent of the persistent addressassigned to the client, the user can registerwith the appropriate SIP-based communi-cation services layer component, such asIP telephony server. When the client’senterprise number is dialed, the clientcan receive the call even if the user isroaming in a different state or country.


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3Com Client Software toEnable Mobile AccessConvergence Applications

3Com’s strategy is to provide access toconvergence applications from users’ desk-tops and mobile devices. Because 3Comconvergence architecture is based on SIP,desktop and mobile devices compliant withSIP (user agents) are required. 3Com offers acomplete array of SIP-compliant desktopdevices, including IP phones and software-based convergence clients. In addition, sinceSIP is becoming a widely accepted standard,several third-party vendors—such as RIM andPulverInnovations—provide SIP-compliantdevices. 3Com plans to offer its own SIP devicesand will work with industry leaders to offer awide array of other SIP-compliant solutions.

Certain aspects of convergence applications,such as data sharing, need a richer userinterface than the interface provided onconventional phones and mobile SIP devices.As previously mentioned, to provide accessto convergence applications from desktopsas well mobile devices, 3Com has implementedthe user interface required for convergenceapplications as a hardware-independent,portable software platform, the ConvergenceCenter Client. 3Com will work with leadingmobile SIP device vendors to port this soft-ware to their platforms, so that the power ofconvergence applications is at users’ finger-tips while they roam.

3Com Convergence Servicesto Enable IP Mobility AcrossPublic Domains

This discussion has focused on mobilitywithin enterprise premises, including roamingacross wireless LAN domains and access toenterprises from remote locations through theInternet. Roaming can also occur when awireless user crosses over from an enterprisewireless LAN to the public cellular air space.Providing the ability to roam from privatewireless LANs to public cellular networks andvice versa is of great interest to 3Com. 3Comrecognizes, however, that this is a complexissue—not only because of the technicalchallenges but also because of the businessand commercial concerns of the variousoperators involved.

To overcome these challenges, multiple inde-pendent networks—including the enterprisenetwork, PSTN (SS7), and public cellularnetworks—must interoperate. In addition,the business entities responsible for thesenetworks must collaborate though part of ahighly competitive environment. Therefore,while 3Com is making significant progress inthis area, especially in solving the technicalissues, fulfillment of this requirement isexpected to take longer than the technicalsolutions that are within 3Com’s control.

In the interim, 3Com understands that usersbenefit from single-identity portability, notjust within enterprise boundaries but alsowhile they are in public wireless space. Inother words, the single number at which callsare received anywhere within the enterprise

must work while the user is roaming outsidethe enterprise. With this in mind, 3Com offersa convergence service for routing user callsto alternate numbers, including those in publicwireless domains. A user can set up a routingprofile that will route all calls to the deviceson which the user’s unqiue identity isauthenticated. These devices will receive thecall first. Furthermore, the user profile canbe set up to try other numbers in case thecall attempts are not successfully completedon the authenticated device.

The capability of finding the user at numbersother than those on the authenticated devicesby sequentially following the user at alternativenumbers is called find me/follow me. With thiscapability, the user can set up a cell phone andother non-SIP-compliant phone number,(such as a home number) as a contact option.

Brandon Regional Health Authority inManitoba, Canada, uses the find me/follow mecapability to enhance its homecare services.The medical center relies on 3Com poweredconvergence applications to enhance bothinternal and public communications. Thebuilt-in find me/follow me service allowshomecare workers to forward their calls totheir tablet PCs equipped with a cellularcommunication capability and 3Com pcXset™

software. This essentially transforms theportable computers into mobile phones thatwork on the road and in patients' homes.

Summary True mobility goes beyond cell phones.Enterprise-level mobility requires cost-effective network options and communica-tion devices for access to convergenceapplications. 3Com takes a broad view ofmobility that encompasses roaming users aswell as remote users who are away from theirdesktops. The 3Com strategy includes iden-tity portability to enable single-numberappearances regardless of the device or thenetwork through which the user is accessingthe convergence applications and services.In addition, the strategy covers access torich convergence applications from a varietyof devices, tethered and mobile, employedby users while they are mobile.

3Com offers a variety of products architectedto work together to provide true mobility. ItsSIP-based convergence architecture delivers

mobility through single-identity portability.Furthermore, 3Com IP mobility solutions solvesecurity concerns by safeguarding the borderof the enterprise network from intruders onthe Internet and by protecting against roguewireless users. These solutions allow users toroam within enterprises and be continuouslyconnected, as well as to roam outside theenterprise and be easily located throughfind me/follow me capabilities.

3Com offers solutions and products thatdeliver the full power of convergencethrough mobility infrastructures. Bybringing about the confluence of enterprisemobility, convergence applications, andconvergence clients that include mobiledevices, 3Com is raising the bar for conver-gence networks.


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3Com Corporation, Corporate Headquarters, 350 Campus Drive, Marlborough, MA 01752-3064

To learn more about 3Com solutions, visit www.3com.com. 3Com is publicly traded on NASDAQ under the symbol COMS.

The information contained in this document represents the current view of 3Com Corporation on the issues discussed as of thedate of publication. Because 3Com must respond to changing market conditions, this paper should not be interpreted to be acommitment on the part of 3Com, and 3Com cannot guarantee the accuracy of any information presented after the date of publication. This document is for informational purposes only; 3Com makes no warranties, express or implied, in this document.

Copyright © 2005 3Com Corporation. All rights reserved. 3Com and the 3Com logo are registered trademarks of 3Com Corporation.Exercise Choice and pcXset are trademarks of 3Com Corporation. Identity-Based Networking and Mobility Domain are trademarksof Trapeze Networks. All other company and product names may be trademarks of their respective companies. While every effortis made to ensure the information given is accurate, 3Com does not accept liability for any errors or mistakes which may arise.Specifications and other information in this document may be subject to change without notice. 503146-001 02/05


ip mobility: raising the bar for convergence networks · 2009. 9. 3. · 3 ip mobility: raising the...

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