IP telephony lifecyclemanagementWhite paper

Table of contentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Managing IP telephony: scoping the problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2HP Management Solution for IP Telephony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

IntroductionThe adoption of IP telephony (IPT) is steadily growingas companies recognize the value of converged voiceand data networks. Growing evidence today suggeststhat IPT will eventually replace traditional telephonytechnology, and sooner rather than later. Helping drivethe success of IPT, early adopters are reaping thepromised benefits of reduced operating costs, increasedefficiency and productivity, and greater flexibility todeploy additional voice-related services.

Of course, IP telephony is not without risk. DeployingIPT can involve significant commitments of capital andresources to replace a high-quality, reliable legacyphone system. In addition, once an IP telephony systemis widely deployed, the phone service it provides isessential for conducting business and for the people whodepend on it—people like customer service representa -tives, sales teams and stock traders, to name a few.Lastly, IP telephony systems are highly complex, real-time systems with stringent quality and availabilityrequirements.

Given the benefits and the risks of IP telephony, it’svital that a company examines the challenges andemploys a rigorous and holistic approach for deployingand managing IP telephony.

This paper reviews the challenges of IP telephony, andthen provides an overview of the HP IP TelephonyManagement Solution. This solution is based on alifecycle approach that optimizes the utilization ofpeople, process and technology for managing IPT.From planning through delivery, to operation, the HPsolution simplifies management of the complex IP tele -phony environment and provides the highly specializedand automated management features needed forsuccess.

Managing IP telephony:scoping the problemThe importance and complexity of an IP telephonysystem creates a number of challenges related tomanaging the environment. These challenges resultfrom the fact that IP telephony:

• Is a business-essential application and thus, drivesstringent quality and availability requirements

• Is one of the first real-time applications to be widelydeployed on the IP network

• Is a service comprised of interdependent technologiesincluding: applications, systems and special network -ing infrastructure

• Is typically rolled out in phases over time

2

2.1 Stringent quality and availabilityIn general, a telephone service is considered a business-essential application. For example, voice communica -tion is essential for discussion and correspondenceamong employees within a company, among a com -pany and its vendors, and among a company and itscustomers. Thus, the availability and quality of thevoice service can impact business performance,including revenue.

Next, in most cases, IP telephony is replacing a highlyreliable and high-quality legacy phone service. Andlegacy phone systems have been known to work evenduring power outages. In order for an IP telephonydeployment to be successful, it must meet or exceedthese existing benchmarks. This translates to 99.999percent (“five nines”) availability and “pin-drop”quality of service (QoS).

At the highest level, these availability and qualitybenchmarks drive the objectives for the managementsystem. For example, an effective management systemshould provide comprehensive and detailed availabilityand quality reporting for the IP telephony system. Also,an effective management system should enable maxi -mum availability and quality through reduced meantime to repair.

2.2 Real-time applicationIP telephony is one of the first widely adopted real-timeapplications to run on the network and this presentssome unique management challenges. As a real-timeapplication, voice service quality is sensitive to networkjitter, latency and packet loss. General thresholds forthese metrics are as follows:

• Maximum jitter can be no higher than 40 milliseconds

• Latency must be less than 100 milliseconds

• Packet loss must be less than 1 percent

To meet these stringent network performance criteria,it’s typical for an IP telephony deployment project toalso include a significant amount of re-engineering of the IP network. Examples of network upgrades tosupport VoIP are provided in Figure 1.

An effective management solution can play importantroles in planning, delivering and supporting a real-time network for VoIP. For example, automaticallyconfiguring L2 and L3 QoS settings across a networkcan improve accuracy and save IT staff time. Further -more, management solutions can be used to monitorand diagnose transient and hard-to-locate voice qualityissues resulting from poor network performanceand/or configurations issues.

3

Figure 1. Network designconsiderations for VoIP ���������

��������������� ��� ��������������������� �� � ������ � ��� �� � �����

����� ����������� �����������

Sources of delay

CODEC (G.729A 25 ms Duplex mismatch Queuing delay Queuing delay Serialization delay (packet loss) (variable) (variable) (variable)

Jitter buffer (20–50 ms) Propagation delay (6.3 ms/Km + variable network delay)

Network design considerations

L2 QoS Separate VLANs for Rapid convergence Rapid convergence Modularityvoice and data

VLAN trunking Rapid convergence IP summarization L3 QoS WAN QoS

Trust boundary L2 QoS L3 QoS Traffic shaping

Link efficiency (LFI)

Source: Ramesh Kaza and Salman Asadullah, “Cisco IP Telephony: Planning, Design, Implementation, Operation, and Optimization,” Cisco Press, pages 117,125, 2005

2.3 Complex and multi-domainsystemIP telephony is a service comprised of interdependenttechnologies including: applications, systems andspecial networking infrastructure—all of which requiremanagement. Figure 2 and Table 1 provide a samplelayout for a distributed IP telephony system and alisting of associated potential problems for the keycomponents.

4

Figure 2. Distributed IP telephonysystem

������ ������

���

������������������ ��

���� ������ ��� ��������� �����������

� ! "# � ! "$ � ! "%

Table 1. IP telephony system component management requirements

Component

IP PBX—call processing system services, application processes, system resources

Gateway, gateway endpoints, channels

IP network

IP phones

An effective management solution should manageacross the entire IP telephony system from the phone, to the IP PBX, to the gateway and throughout the IPnetwork. Furthermore, it should manage for servicelevels, faults, availability, performance, capacity, etc.

2.4 Phased rolloutsFinally, within an enterprise, IP telephony is typicallyrolled out in a phased approach versus all at once andthis drives special management considerations. Thereare several reasons for phased implementations of IPTincluding: mergers and acquisitions, depreciationschedules of legacy telephony systems, brand newsites and, probably most importantly, enterprises workto increase IPT deployment success by building acenter of expertise around IP telephony deployments.Thus, a management solution should accommodate thelifecycle nature of IPT deployments. For example, theIPT management solution should be able to expandand scale as the IPT system grows overtime and itincorporates reusable templates (e.g. network config -uration templates for QoS).

Potential problems

Application availabilityApplication process faultSystem overload

OverutilizationGateway endpoint shows availability but zero utilization

Availability and performance of IP network

Routing configuration error sends voice traffic through inefficient path

Poor quality during call

HP ManagementSolution for IP TelephonyThe complexities of an IP telephony system and itsphased deployment schedule create many challenges.To handle these technical and management challenges,it’s prudent to adopt a rigorous and holistic manage -ment approach. One such approach is provided by theIT Infrastructure Library (ITIL).1 ITIL provides an applica -tion lifecycle management model, which offers a bestpractice framework that accommodates people, pro -cesses and technology and is well suited for IP telephony.And because it’s a lifecycle model, it matches thephased rollout plans typical of IP telephony deployments.

The HP IP Telephony Management Solution is basedon the ITIL application lifecycle management modeland is depicted in Figure 3.

The following sections describe how the HPManagement Solution for IP Telephony helps enable a successful IPT project at each stage of the lifecycle.

3.1 PlanThe first step toward migrating to IP telephony is towork through the business case. Companies deploy IPtelephony for economic and productivity benefits andan ROI analysis is a common first step. This paperassumes this step is complete.

Once the business justification has been completed,the technology planning begins. The key objective ofthe technology-planning phase is to gather data for thedelivery phase. So it’s important to look ahead to thedelivery phase to understand what data is necessaryto complete an effective design. Following are exam -ples of types of information collected during theplanning phase:

• Reliability of the existing network

• Redundancy and resiliency of existing network

• Capacity (bandwidth and ports) of existing network

• Performance of existing wide area network (WAN) to handle IPT traffic

The HP IP Telephony Management Solution providesseveral automated capabilities to aid in the planningphase. These capabilities include the following:

• Network availability and fault reporting to determinethe overall reliability of the network and individualcomponents. This reporting enables the identificationof network devices with the highest overall fault countsand the lowest mean time between failures, whichare potential weak links within the network.

• Automated network discovery and topology mapping.This can be used as the basis for network architec -ture analysis (i.e. subscription ratios between access,distribution and core layers).

• Automated network inventory reporting. Inventoryreports can be used to identify legacy networkhardware and software to assess upgrades that willbe required to support VoIP (e.g. identify whichswitches support L2 QoS and rapid convergencetechnologies).

• Network performance reporting and capacityplanning for establishing existing baseline capacityand performance. For example, performance reportscan identify congested devices, interfaces and links.

1The Information Technology Infrastructure Library (ITIL) is a framework of bestpractice approaches intended to facilitate the delivery of high quality informa -tion technology (IT) services. ITIL outlines an extensive set of managementprocedures that are intended to support businesses in achieving both qualityand value for money in IT operations. These procedures are supplier-independent and have been developed to provide guidance across thebreadth of IT infrastructure, development and operations. [Source: Wikipedia]

5

Figure 3. IP telephonymanagement lifecycle

DeliverPlan

Operate

Plan Deliver Operate

IPT business case/ROI NW routing service design Fault, availability, diagnostics

Information and data gathering QoS policy determination Service level management

Network configuration Performance management

Capacity planning

3.2 DeliverThe second phase of the IP telephony lifecycle is thedelivery phase. The delivery phase includes bothdesign and provisioning tasks. The design tasks utilizethe information and data collected during the planningphase to design the IP telephony system and the under -lying IP network to support VoIP. The provisioning tasksinvolve implementing and commissioning those designs.HP IP Telephony Management Solution provides cap -abilities to support the design and delivery tasks withinthe delivery phase.

DesignThere are many aspects associated with designing anIP telephony system. However, this paper only focuseson some of the design tasks associated with the IPnetwork to support VoIP that are aided by HP software.

The first area of focus is associated with network con -figurations for VoIP. Because of the connectionlessnature and required real-time performance of VoIP, it’s common to deploy special network configurations.Examples of configurations deployed to support VoIPinclude the following: separate VLANs for voice data,layer 2 and layer 3 quality of service and advancedrouter settings (e.g. link fragment interleaving). But inlarge multi-vendor environments, planning and designfor network configurations can be a tedious, time con -suming and error prone. Automated network changeand configuration management software by HP pro -vides a significant amount of automation and controlfor these tasks.

Another key area of design for the network is the IPnetwork routing service. Migrating from traditionaltelephony to IP telephony places additional traffic onthe network and it must be designed for. HP providesautomated simulation and modeling capabilities to aidin the design process for routed networks.

6

Figure 4. Route analyticmanagement system (RAMS)traffic view showing networkperformance baseline

Table 2. VoIP bandwidth calculation example

Small site Medium site Large site

Phones 250 1,000 5,000

Call profile

Utilization 20% 20% 20%

Simultaneous calls 50 200 1000

Internal 60% 60% 60%

Internal calls 30 120 600

Intersite (LAN) 60% 60% 60%

Intrasite (WAN) 40% 40% 40%

Intersite calls (LAN) 18 72 360

Intrasite calls (WAN) 11 43 216

External PSTN 40% 40% 40%

External calls (PSTN) 20 80 400

Utilization codec 6.711 (64 Kbps) 3.2 Mbps 12.8 Mbps 64 Mbps

The following example illustrates how HP softwareautomates this process. First, the performance baselineis automatically captured from the existing network(see Figure 4 above). Then, the required VoIP band -width is estimated using a table similar to Table 2.Next, the estimated VoIP traffic load is injected into thenetwork using an HP simulation and modeling engine.This modeling engine recalculates the routes and trafficacross the network and develops reports showing thenew state. See Figure 5. At this point, operators canchange network infrastructure and configurations andre-run simulations to optimize the network to supportthe VoIP traffic.

ProvisioningOnce the design phase is complete, the desired statemust be provisioned throughout the network. Networkchanges and configurations must be carefully imple -mented, equipment must be commissioned and itsproper functioning verified. This typically involves:

• Deploying and configuring new hardware

• Deploying new quality of service policies

• Provisioning the IP telephony system (IP PBX,Gateways, etc.)

HP IP Telephony Management Solution provides auto -mation for several tasks associated with provisioningthe IP telephony system. First, HP provides automatednetwork change and configuration management forautomating the configuration of network devices (e.g.L2 and L3 QoS configuration policies). Furthermore,HP WAN optimization capabilities enable real-timeviews of routing and traffic analysis for validatingexpected network performance.

3.3 OperateThe final phase in the IP telephony lifecycle is the opera -tional phase. The objective of the operational phase isto maintain the desired state for the IP telephony system(i.e. to increase its availability and performance).Because an IP telephony system is a complex multi-domain system a comprehensive end-to-end solution is required. That is, a solution that provides for themanagement of IP telephony services, applications,systems and networks. Furthermore, it’s critical that theHP IP Telephony Management Solution is integral witha company’s existing operational management frame -work to enable efficiency.

HP provides a comprehensive solution for managingthe operational phase of the IP telephony lifecycle,which includes the following: fault and availabilitymanagement, performance management, capacityplanning and service level management. Following aredescriptions of each.

Fault and availability managementThe HP solution provides for end-to-end IP telephonyfault and availability management. The dashboardpresented in Figure 6, illustrates the breadth of the HPsolution. For example, it provides status indicators forIP telephony services (e.g. route patterns), IP PBXresources and performance monitoring statistics, gate -keepers and gateway endpoints, all in one view. Fromthis one view, operators can quickly assess the healthof their cross-domain IP telephony system and respond

efficiently. Also, each status indicator enables drill-down to underlying real-time metrics for additionalinformation and links to performance reporting andcapacity planning.

In addition to overall monitoring of the IP telephonysystem, HP provides advanced diagnostic capabilities.Voice quality issues can be difficult to detect anddiagnose. The HP solution is designed to catch voicequality issues in real-time (i.e. while they are occurring).The HP solution initiates when call metrics exceedperformance thresholds and automatically analyzes thenetwork path among phones to isolate the problem. Animportant benefit of this approach is that, once set up,it works automatically without operator involvement.

Performance managementPerformance management is about verifying that the IP telephony system operates within acceptable perfor -mance thresholds on an ongoing basis and it’s aboutcapturing data for diagnostics. The HP solution pro -vides performance reporting and monitoring across an IP telephony system for the following:

• CallManager system resources: CPU, memory, diskusage

• CallManager usage/load: calls active, calls rejecteddue to call throttling

• Call statistics: call success ratio (CSR), disconnectcause, call type distribution

• Gateway, Gateway endpoints and Gateway endpointchannels: availability and usage

7

Figure 5. Network topologyshowing redesigned networklinks

Figure 6. Network nodemanager smart plug-in (NNMSPI) for IPT IP communicationconsole

Capacity planningCapacity planning verifies that the IP telephony systemis right-sized. Most of the data that is collected for faultand availability management and performance man -agement is automatically trended and forecasted forcapacity planning. For example, CallManager systemresource metrics, such as CPU utilization, are trendedand alerts can be generated when forecasted trendsexceed acceptable capacity limits. Capacity planning isprovided for the entire system including CallManagers,CallManager clusters, Gateways and Gatewayendpoints.

Service level managementAs with other business services, service level reporting isessential to provide ongoing service health and quality.Furthermore, service level reporting provides evidenceand justification as to the success of an IP telephonyproject for stakeholders. The HP solution provides forautomated service level reporting for service availability

(voice services), CallManager availability and voicequality (i.e. minimum mean opinion score (MOS),average MOS and maximum MOS reporting).

ConclusionIn summary, HP IP Telephony Management Solutionprovides the capabilities necessary to manage the IPTlifecycle and delivers: • Increased service availability and performance for

the business-essential voice service• Reduced business risk and successful deployments of

VoIP• Reduced capital and operational expense via

optimized converged infrastructure • Increased operational efficiency and productivity for

converged operations teams, engineering and telecom

To learn more, visit www.hp.com/go/software© Copyright 2007 Hewlett-Packard Development Company, L.P. The information contained herein is subject tochange without notice. The only warranties for HP products and services are set forth in the express warrantystatements accompanying such products and services. Nothing herein should be construed as constituting anadditional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein.

4AA1-6016ENW, October 2007

Figure 7. Automatic root-causeanalysis for voice quality issues NNM + IPT SPI

SNMP Collect

BLR_EdgeRouter

RCA Event

L2

SNMP Collect

IPSLA Tests

HP ProblemDiagnosis

x142

DEN_EdgeRouter

L2

Figure 8. Voice quality servicelevel reporting: mean opinionscore (MOS) reporting

WAN Problem between Nodes BLR_Edge and DEN_Edge,Phone: Src. Ext 132 (15.106.79.68) Dest. Ext. 142 (15.10.79.93)