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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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xxx-xxx-xxxx
xxx-xxx-xxxx xxx-xxx-xxxx
xxx-xxx-xxxx
xxx-xxx-xxxxxxx-xxx-xxxx
xxx-xxx-xxxx
xxx-xxx-xxxx
Corporate Location Corporate Location
PSTN
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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IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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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IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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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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IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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
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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
IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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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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IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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
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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.
IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
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.
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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.
IP MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS
10
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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 MOBIL ITY: RAISING THE BAR FOR CONVERGENCE NETWORKS