MGW Performance Management Overview

MGW Performance ManagementOverview

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MGW Performance Management Overview

Contents

Contents 3

1 Performance management in MGW 5

2 Performance Management functionalities in NEMU 9

3 3GPP terminology differences 13

4 Performance monitoring functions 154.1 Periodic measurements 154.1.1 Service, transport and HW measurements 154.1.2 Measurement management 174.1.3 Measurement presentation in MGW 174.1.4 Reference Information Service (RISE) 184.2 Trace observation in MGW 184.3 Key performance indicators 204.4 Threshold-based notifications 21

5 Troubleshooting documents 23

6 Performance monitoring documents 25

Related Topics 27



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Contents

1 Performance management in MGW

Table 1. Performance management in different MGWnetwork environments

Functionality Applicable in MGW

MGW forMSC

MGW inUNC(UMA)

MGW forMSS

Performancemanagement

x x x

As MGW is an independent network element, it has to offer resourcemanagement capabilities to support operators since they need MGW performancedata to support network (element) dimensioning. By functionality, MGWperformance management can be divided into measurements and traceobservation. Measurements count events, data, or volume of the measuredobject(s). The measurement report is generated at the end of each resultaccumulation period.

For description of trace observation, see Trace observation in MGW.

In order to help the operator to optimal use of the network, MGW providesdetailed statistical reports on the resource usage related to different interfaces.Since MGW can be controlled by several MSC Servers, it is essential that thededicated resources are optimally utilised.

The operator can define a certain statistical measurement to start immediately orat a certain point of time (date and time). The measurement is active until theoperator stops it or when the predefined end time is reached (on condition that theend time has been defined when starting the measurement). The operator candefine a period of time (from 15 up to 60 minutes) for the measurement reports,that is, how frequently measurement reports are generated. The recommendedmeasurement interval is 60 minutes.



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Performance management in MGW

The statistical measurements in MGW can be controlled by using theMeasurement Handling (T2) MML and/or the NE Measurement Explorer GUI inNEMU. However, there are two exceptions to controlling the measurements withthe T2 MML, namely, PDH an SS7 measurements. Their measurement structureis not the same as that of the other measurements, and their reports can be seen inMGW with an MML command or with NEMU's www browser.

MGW performance management consists of the following measurements:

Table 2. MGW measurements

Measurement MeasurementID (MID)

Applicable in MGW

MGW forMSC

MGW inUNC(UMA)

MGW forMSS

Interface-specific TCmeasurement

512/200H x x

STM-1 interfacemeasurement

513/201H x x

IMA logical interfacemeasurement

514/202H x x

SONET/SDH protectiongroup measurement

516/204H x x

ATM layer performancemeasurement

528/210H x x

ATM virtual pathconnection measurement

529/211H x x

ATM virtual channelconnection measurement

530/212H x x

AAL5 protocolmeasurement in DMX

547/223H x x

AAL5 protocolmeasurement in Chorus

549/225H x x

AAL2 Path CAC resourcemeasurement

550/226H x x

AAL2 signalling at NNImeasurement

552/228H x x




Table 2. MGW measurements (cont.)


Applicable in MGW

MGW forMSC

MGW inUNC(UMA)

MGW forMSS

Ethernet interfacemeasurement

561/231H x x x

TCP/IP protocolmeasurement

563/233H x x x

Unit load measurement 592/250H x x x

Overload control with WACperformancemeasurement

594/252H x x x

Availability performancemeasurement

608/260H x x? x

DSP performancemeasurement in MGW

614/266H x x? x

RANAP protocolmeasurement

640/280H x

BSSAP protocolmeasurement

641/281H x

BID protocol measurement 642/282H x

Signalling transcodingmeasurement

643/283H x

Multi-party callmeasurement

644/284H x

Connection measurement 645/285H x

RTP/RTCP protocolmeasurement

646/286H x x

TrFO and TFOmeasurement

648/288H x

Data call measurement 649/289H x



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Performance management in MGW

Table 2. MGW measurements (cont.)


Applicable in MGW

MGW forMSC

MGW inUNC(UMA)

MGW forMSS

Announcementmeasurement

656/290H x

H.248 measurement 658/292H x

Acoustic EchoCancellation measurement

660/294H x

User Plane initialisationmeasurement

662/296H x

MGWoffers long-term performance data rather than single call -related data. Onephysical MGW can be divided up to several virtual MGWs (VMGW).

The system produces a measurement report at the end of each result accumulationperiod. There are two ways to examine the measurement reports:

. By using NEMU's NE Measurement Explorer. For instructions, see UsingNE Measurement Explorer.

. By using Nokia NetAct. At the end of each result accumulation period, themeasurements reports are transferred to NEMU, from where they aredelivered to Nokia NetAct. The performance management post-processingfor the reports is done in NEMU. For more information on performancemanagement post-processing, see Performance ManagementFunctionalities in NEMU.




2 Performance Managementfunctionalities in NEMU

Table 3. Performance Management functionalities in NEMUin different MGW network environments


MGW forMSC

MGW inUNC(UMA)

MGW forMSS

PerformanceManagementfunctionalities in NEMU

x x x

Performance Management (PM) post-processing is a Network ElementManagement Unit (NEMU) functionality which is used to transfer performancemeasurement result files from MGW to NEMU database. The operator can use anapplication called NE Measurement Explorer (GUI) to view and control all themeasurements and counters transferred to the NEMU database in textual form.

NE Measurement Explorer

The main components of the NE Measurement Explorer are the Explorer view,Measurement Management view and Browser starting dialogue.

Explorer view:

The Explorer view of the NE Measurement Explorer is used for viewingmeasurement data stored to the NEMU database. The view contains the followingparts:

. measurement type list (for selecting a measurement)

. object list (for selecting the target object of the measurement)



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Performance Management functionalities in NEMU

. save time list (for selecting the save time of the measurement)

. counter list (shows all the counters of the selected measurement type)

. KPI list (shows all user-defined KPIs of the selected measurement type)

In NE Measurement Explorer, there are two ways to get the counter values of aparticular measurement. When the measurement type is selected, the user cansearch all measurement objects of the selected measurement type and then searchall the save times of the selected measurement object. Alternatively, the user canselect the measurement type first, then search for all the save times of themeasurement and finally search for all the measurement objects of the selectedsave time. In both cases, the user selects the measurement type, target object andthe save time. When all of these parameters are known, the user is able to obtainthe counter and KPI values. The KPIs can be created using the NE ThresholdManagement application.

Measurement Management view:

The Measurement Management functionality is integrated into the NEMeasurement Explorer GUI. It provides a tool for easy-to-use graphicalmeasurement handling (that is, starting and stopping of the measurements) thatcan be used alongside with the Measurement Handling (T2) MML interface.

Browser starting dialogue:

Browser starting dialogue is used for opening the default web browser to a www-page in the NEMU web server containing the SS7 and PDH measurement reportsin textual form.

NE threshold management

The Element Manager GUI can be used for setting, removing and modifyingthreshold monitoring parameters. An operator can use predefined keyperformance indicators (KPI) or define customized KPI formulas. KPIs includeeither an individual counter or a combination of several counters, which arecollected in the network.

Note

In MGW NEMU, it is possible to create KPIs. However, if you wish to usepredefined KPIs, NetAct provides an optional MGW Reporting Suite thatconsists of predefined MGW reports and KPIs.




See Threshold-based notifications for more information on thresholds, and Keyperformance indicators for KPI information.



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3 3GPP terminology differences

Some measurement-related terms used in MGW documentation have differentmeaning than in 3GPP documentation.

Another point to notice in measurement terminology is that the 3GPPdocumentation uses terms that are not specifically defined in the 3GPP�Definitions� clause. Therefore, many of the 3GPP definitions presented in thischapter are Nokia interpretations of the 3GPP document. 3GPP is currentlyworking on the definitions and will hopefully define the terminology more clearlyin the future.

The table below describes the most important terminology differences betweenMGW and 3GPP documentation.

Table 4. Nokia Terms

Nokia Term Description Nearest 3GPP term

Measurement,Measurement type

Set of counters which canbe separately managed

Measurement family

Counter Measurement resultconsisting of a single valueand correspondingdefinition

Sub-Counter1

Counter, MeasurementType2

Key PerformanceIndicator (KPI)

Performance indicators,which are valuable for theoperator. KPI is calculatedas a function of one ormore counters.

Not available

1 Sub-Counter3GPP = A more detailed indicator for a specific Counter3GPP. Afailure Counter3GPP, for example, can have specific sub-counters for each separatefailure cause.

2 Counter3GPP = Measurement type3GPP which includes one or moreCountersNokia



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3GPP terminology differences

4 Performance monitoring functions

4.1 Periodic measurements

4.1.1 Service, transport and HW measurements

Transport and HW measurements provide statistical information on signalling, IP/ATM/TDM transport, DSP resources and the physical layer serving the transportnetwork.

Measurements that describe the transport network and Multimedia Gateway(MGW) internal performance are listed in the following table. The measurementsare divided into five groups according to their use.

Group of use Measurements

Transport network resources andservices

AAL2 path CAC resource

Announcement

Data call

TrFO and TFO

Connection

Multiparty call

Signalling transcoding

DSP performance

AEC

User plane initialisation

Signalling RANAP, BSSAP' and BID protocols(MGW for MSC)

AAL2 signalling at NNI

SS7 signalling



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Performance monitoring functions

Group of use Measurements

TDM/ATM/IP transport Interface-specific TC

ATM layer performance

TCP/IP protocol

AAL5 protocol in Chorus

AAL5 protocol in DMX

ATM VP/VC connection

RTP/RTCP protocol

H.248 protocol

Transmission quality STM-1 interface

IMA logical interface

PDH interface

SONET/SDH protection group

Physical layer Availability performance

Unit load

Overload control with WAC performance

Transport network resources and services describe the use of network resourcesfrom the upper layer service point of view.

All measurements related to transport layer signalling are in the second group.

The measurements related to TDM, ATM and IP protocols compose the thirdgroup.

The transmission quality measurements include the standard SDH and PDHmeasurements related to physical transmission.

The last group consists of the computing unit measurements that provide statisticson the load and availability of MGW units.

Detailed measurement and counter information can be found in documents MGWMeasurement and Trace Management, MGW Counters - Resource and ServicePart and MGW Counters - Transport and HW Part.




4.1.2 Measurement management

Service, transport and HW measurements in the MGW can be managed either byusing MMLs or NE Measurement Explorer GUI. MGW measurementmanagement is presented in the following figure.

Figure 1. MGW measurement management

The handling of measurement schedules and timing of data collection are locatedin OMU. From OMU the data is transferred to NEMU where it is post-processedand stored in the NEMU database.

NEMU sends the data further to NetAct, where it is stored in the database. Thedata can be analysed using the NetAct reporting applications.

SS7 and PDH measurements can be managed only by using MML. SS7 and PDHmeasurement data is stored in the NEMU disk as ASCII-formatted reports, whichcan be viewed with a web browser launched via NE Measurement Explorer. Notethat SS7 and PDH measurement data is not transferred to NetAct.

4.1.3 Measurement presentation in MGW

The measurement data of service, transport, and HW measurements can beviewed from the NEMU database using NE Measurement Explorer GUI.

measurementreports

NetAct

measurement reportsMGW

MGW EM (NEMU)



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The storage time in the NEMU database is seven days after which data isoverwritten. All data of these measurements is also transferred to NetAct where itcan be viewed using the reporting tools available in the NetAct.

SS7 and PDH measurement data is stored in the NEMU disk as ASCII-formattedreports, which can be viewed with a web browser launched via NE MeasurementExplorer.

4.1.4 Reference Information Service (RISE)

The main sources of counter information are the performance monitoringdocuments, to which this document also belongs. However, the documentscannot be updated immediately after each counter improvement action. Thepurpose of the Reference Information Service (RISE) is to bring the latest counterinformation immediately available to the customers.

RISE can be found under Nokia Online Services� Documentation� ReferenceInformation.

4.2 Trace observation in MGW

Table 5. Trace observation in different MGW network environments


MGW forMSC

MGW forMSS

MGW forIMS

MGW forUMA

RANAP trace x

IMSI trace x

Monitoring erroneous Iuand A' interfacemessages

x

IMSI / IMEI traceobservation

x x x




As MGW is an independent network element, it has to offer resourcemanagement capabilities to support both operators and vendors. Operators needMGW performance data to support network (element) dimensioning, and vendorsneed data on network element performance (such as possible fault situations). Byfunctionality, MGW performance can be divided to measurements and traceobservation. For more information on measurements, see Performancemanagement in MGW.

RANAP trace in MGW for MSC

MGW for MSC uses RANAP trace for monitoring the conversion process fortesting and fault tracing purposes. When tracing, it is possible to get either themessage identity or full content of the message. You can also select whichmessages are monitored.

RANAP trace can be started in two ways. First, it can be started by the mobileservices switching centre (MSC) by sending the msc_invoke_trace message toMGW for MSC. Trace can be invoked either in MGW for MSC or in both MGWfor MSC and radio network controller (RNC). Secondly, RANAP trace can bestarted locally via an MML command in MGW for MSC. In this case, trace canbe invoked only in MGW for MSC. The trace reports are stored on the OMUdisk.

IMSI trace in MGW for MSC

The IMSI trace in MGW for MSC is used for testing and fault solving. It providesinformation on the RANAP/BSSMAP messages and error codes for selectedIMSIs.

Monitoring erroneous Iu and A' interface messages

For internal fault solving, there is a cyclic buffer for erroneous messages. When aprogram block receives an erroneous message, the message is stored in the cyclicbuffer. The cyclic buffer can contain up to 200 erroneous messages and additionalinformation about the failure (for example, time of the failure).

Cyclic buffer is also used for storing error codes of user plane applications. Thecontents of the buffer can be output with MML commands.

IMSI / IMEI trace observation in MGW for MSS / MGW for IMS / MGW for UMA

MSC Server sends a trace activation (H.248 add command) to MGW viaMEGACO in a Nokia-specific package when the termination reservation isrequested by MSC Server. The maximum number of simultaneous trace cases inone MGW is limited and if the number of trace cases reaches the limit, MGWdiscards the trace activation and sends a notification to MSC Server if thenotification event has been armed.



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MSC Server also sends an H.248 modify command to activate trace. The use ofH.248 modify commands enables trace activation also in MGW located on theother end of the ATM/IP/TDM backbone even though its termination is alreadyreserved. Thus it is possible to get trace reports in all call cases.

MSC Server can also deactivate IMSI/IMEI with the H.248 modify command.

The trace records generated in MGW are sent to the Nokia NetAct throughNEMU. The trace results are stored in MGW and the full report files aretransferred to NEMU after the trace event is finished. NEMU sends reports toNokia NetAct by using the Nokia proprietary NWI3 interface.

Trace observation can be used by subscriber administration and networkmanagement for subscriber observation (for example, following a customercomplaint, or when the network operator suspects that an equipment malfunctionhas taken place). MSC Server includes an IMSI/IMEI type indication in the traceactivation that it sends to MGW, which makes it possible to monitor activesubscriber traces via the NetAct Trace Viewer. By utilising IMSI/IMEI typeindications, the NetAct Trace Viewer can be used to trace multiple subscribers(SIM cards) simultaneously.

Enhanced MGW trace database provides a logical database structure and plentyof space for traced terminations.

4.3 Key performance indicators

Key performance indicator (KPI) is a function of counters. In its simplest form,KPI is an individual counter.

The reason behind the KPI concept is that the information provided by a singlecounter value is rarely sufficient. The operator also needs information on networkperformance in a compact form to minimise human analysis effort. With carefullydefined KPIs, the operator can easily get information on the performance, level ofusage and malfunctions encountered in the network element.

There are two kinds of KPIs:

. Nokia-defined KPIs (as defined by NetAct documentation)

. User-defined KPIs

KPI calculation can be carried out in MGW, NetAct, and with third party tools.This section concentrates on KPI calculation which is carried out in MGW.




The operator can view MGW KPIs via MGW Element Manager (MGW EM).Transport network and HW KPIs can be viewed via NE Measurement ExplorerGUI.

The operator can use predefined KPIs or define their own customised KPIformulas. The operator can create and modify KPIs via NE ThresholdManagement GUI (part of MGW EM).

Figure 2. KPI Calculation in MGW

In addition to NetAct, the tools available in MGW NEMU allow the operator toanalyse measurement data. This may be the case when the operator does not wantto transfer all measurement data to NetAct (for example, because of capacityreasons).

NetAct tools provide an overall picture of network performance while MGWtools can be used to see deeper into the network element, for example, introubleshooting.

For more information on MGW KPI calculation, see the online help of the NEThreshold Management GUI (part of MGW EM).

4.4 Threshold-based notifications

The operator can define thresholds for counters and MGW Key PerformanceIndicators (KPIs). If a threshold is exceeded, MGW sends a notification toNetAct.

measurementdata

NetAct

define KPI

KPI values

MGW

PredefinedKPIs

User-definedKPIs

MGW EM (NEMU)



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With this feature

. the operator can quickly detect problems worth attention, and at the sametime

. the operator can decrease the amount of measurement data that needs to betransferred to NetAct.

Threshold-based notifications can be used also as a proactive method for networkmanagement. Thresholds can be set so that problems are noticed before theybecome too severe.

The operator can create and modify thresholds via NE Threshold ManagementGUI, which is part of MGW Element Manager (MGW EM).

Figure 3. Threshold-based notification

The counter and KPI values of active measurements are compared against activethreshold values. When a threshold is exceeded, a threshold notification is sent toNetAct. In addition, a threshold event log is stored in the network element forlater study.

For more information, see the online help of MGW Threshold Management GUI(part of MGW EM).

measurementdata

NetAct

set threshold

threshold logMGW

thresholdnotification

MGW EM (NEMU)




5 Troubleshooting documents

Troubleshooting issues related to MGW performance management are discussedin the document MGW Measurement and Trace Management.

Note

A copy of the troubleshooting chapter of the MGW Measurement and TraceManagement is also included in the document Troubleshooting MGW.



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Troubleshooting documents

6 Performance monitoring documents

Table 6. Performance monitoring documents

Document name Content

MGW Performance ManagementOverview

Provides an overall picture of MGWperformance management and traceobservation.

MGW Measurement and TraceManagement

Describes the management of MGWmeasurements. The document alsoincludes a description of subscriber andequipment trace.

MGW Counters - Resource and ServicePart

Describes the performance counters ofresource and service -related MGWmeasurements.

MGW Counters - Transport and HW Part Describes the performance counters oftransport and HW -related MGWmeasurements.

Multimedia Gateway Trace Report inNEMU

Describes subscriber trace post-processing.



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Performance monitoring documents

Related Topics


Descriptions

NEMU in MGW

Trace observation in MGW

Descriptions

RANAP trace in MGW for MSC

IMEI/IMSI trace observation in MGW for MSS

Instructions

Monitoring erroneous Iu and A' interface messages in MGW for MSC

Handling IMSI trace in MGW for MSC



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Related Topics

MGW Performance Management Overview

Documents

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