1. QSZ225

QSZ225, tendered from ZCTT, provides complete real-time analysis for performance, QoS and user behavior of PSTN, GSM, CDMA (CDMA2000), GPRS and IN by expanding its penetration both into SS7 and into Datacom. Combining innovative features, functionality and performance into a single cost-effective product, the QSZ225 is the most advanced testing platform available today.


Physical Layaer Performance Management
QSZ225 scans channel physical characteristics to adapt its configuration to testing environment automatically and master physical layer performance :

  • auto PCM signaling timeslot searching and corresponding protocol loading
  • link-level transmission performance alarm and load alarm monitoring
  • DPC and OPC scanning and test, confirming relation between Tx/Rx of link and two end offices
  • real-time data storage, real time and in-office analysis, time test and data collection

Link Performance Statistics

Analysis includes CRC error, retransmission number, FISU count, LSSU count and number of various LSSU messages in Tx & Rx of signaling link. Link load real-time curve provides graphic display for time-sharing Erl value, which offers user direct view of peak value and nadir value.

Statistics of abnormal message is designed for locating detailed switch-related troubles:
1) ACC automatic congestion control failure
2) RSC, GRS/GRA, BLO/BLA occurrence
3) H/M/S series maintenance-originated and blocking messages burst;
4) too much SAO and GRQ/GSM meaning adjusting inter-office relay usage method.

Testing in SCCP aims at UDTS message including SCCP error, SCCP rejection and SCCP return. TCAP analysis provides statistics of TCAP transaction operation such as Start, Resume, Unidata, End, Abort, Reserved at Tx and Rx ends. TCAP_ABORT is the key indicator of TCAP problem meaning inefficacy transactions occurrence or absence of processing capacity of network entities such as SSP, SCP, and IP.

Protocol Resolving

  • Automatic decoding for all SS7 signaling message, including LSSU, SNT, SNM, TUP, ISUP, SCCP, TCAP, INAP, MAP, CAP, BSSAP, Abis.
  • Displaying signaling message in various styles: main event content, detailed extended decoding and original code stream
  • Detailed signaling message filter settings subscriber label: calling number, called number, MSISDN, IMSI, MIN, GT...
    signaling label : protocol layer, message type, parameter type, error type, event type, process result..
    network label: direction code, DPC, OPC, link... with supporting wildcard (*.?).
  • Providing key field prompt function, such as message time, message type, calling subsriber number, called subscriber number, release reason and error reason etc to help technician pay more attention to these import message.
  • Automatic link to deriving call follow for every signaling message. For example, when technician gets one ISUP_CFN message, he could obtain all related signaling flow on new window by clicking on this message.

Full-protocol & Multi-interface Call Trace
Network problem may be caused by equipment fault or cooperation failure between two equipments. Error message may be generated in different network segment and transported via other related signaling link, which could bring out more failure message. Error message caught in one interface may be mapped into another one. The Traceer must be able to ombine all related messages of different network segments into one complete sequence even when they belong to different protocol stack.

QSZ-225 support automatic search and combination for message among multiple interfaces: finding all messages belonged to the same event or process (call, transaction) and displaying messages in "Call Flow Chart", which is used to help technician master interaction of different network segment entities and locate signaling fault with help from detailed decoding of selected message in correlation windows.

Network QoS Analysis
Network service quality is influenced by various factors. CCR (Call Completion Rate) refflects basic network service quality. QSZ-225 implements time-sharing statistics for all stored CDR, including CCR, seizure times, answer, answer time-out and call drop according to office direction and call number in different time duration for incoming call, outgoing call, forwarding call and terminating call. Statistics result could be sort by any item. Top N analysis for CCR is used to help technician locate lowest QOS area/direction.

Call responding time reflects processing speed of network entities. The function implements time-sharing statistics of network responding time for all stored CDR and calculates maximum value, minimum value and average value. Network responding time is time difference between the time when sending IAM/IAI and the time when receiving the first response message such as ACM/GRQ/SLB/CFL, and it must conform to network specification for different interoperation of network entities. The movement of average network responding time refflects movement of network call service quality and change of processing ability of switch movement of average network responding time reflects movement of network call service quality and change of processing ability of switch.

Operators can query detailed CDR records and original signaling data by :

  • start time
  • source id (such as calling subscriber number)
  • destination id (such as called subscriber number)
  • holding resource (such as circuit id-CIC)
  • result
  • duration
  • message sequence

Circuit Usage Analysis
Analysis of circuit usage helps operator master distribution of subscriber traffice :

  • usage balance between different incoming/outgoing circuits both from PCM scale and from CIC scale. It can be used to look for dual-seizure calls, uni-connection calls and blank circuit caused by switching circuit control configuration.
  • call duration balance between different incoming/ougoing circuits both from PCM scale and from CIC scale. It is used to detect abnormal circuit occupation in some direction such as too short average duration meaning severe circuit fault.

User Call Inspection
User Call Inspection focuses on user call behavior statistics on various call parameters and generate sorted list for distinguishing exceptional user charactered with abnormal ACM count, CCR, ANC count, ANU count and call drop counts or any of them. Testing provides :

  • Subscriber sorting list with maximum engaged times
  • Subscriber sorting list with maximum chargeable/unchargeable answer
  • Subscriber sorting list with highest/lowest CCR
  • Subscriber sorting list with maximum answer time-out
  • Subscriber sorting list with highest busy call rate
  • Subscriber sorting list with maximum LOS
  • Subscriber sorting list with maximum CFL
  • Call number sorting list with maximum UNN

Call Loss Delving
Reducing call loss is ever kept as the key task of network maintenance. Call Loss Delving carries otu comprehensive resolution of call loss including network (direction) CCR, seizure, bidding, answer, waiting time-out, SLB, STB, SEC, CGC, CFL, ADI, LOS, SST, UNN and other special call drop reason, such as call dual-seizure, according to switch code, OPC/DPC, prefix and area code etc.

Call dual-seizure test provides detailed record of dual-seizure call, whose content includes happening time, route id (DPC, OPC, CIC) and call record message sequence. Clicking every dual-seizure record will fetch related call flow so as to see whether controlling subscriber made successful call and whether the other party reselected circuit.

Mass Traffice Test
Long-time mass subscriber traffic test on switch verify :

  • Performance of switching capacity
  • Veracity of billing
  • Veracity of switch counters

Mass subscriber traffic test is used for switch installation, capability expansion, update test and periodic test of import switch office. Long-time call test is also used for finding equipment with mass congestion.

Mobility Service Analysis
Mobile transaction such as subscriber roaming influence performance of mobile communication network. GSZ-225 provides analysis of mobility service for GSM/CDMA/GPRS from three different views.

MAP operation
Statistics is used to monitor detailed distribution of MAP operations such as Location update, Send identification information, Send routing message, Provides roaming number and SMS service etc for network optimization and planning. Meanwhile, MAP performance including operation quantity, success amount/ration, and failure amount/ratio is combined into together. Based on above acknowledge of overall MAP service, MAP error and reason in the specified office direction is given for probing network fault.

MAP User
Analysis of user activity is used to analyze mobility of subscriber and help operator distinguish different subscriber groups with special features such as regular roaming, large SMS consumption, regular shut off and long-time off line. It could help operator find network/subscriber configuration problem and master mobility activity rules of subscriber groups, so as to expand market and prevent fraud. IMSI and MSISDM (CDMA MAP_MN) are both taken as user identifier for following objects :

  • total service amount
  • total failure amount
  • Roaming amount, failed roaming amount
  • CM amount, failed CM amount
  • other service amount, failed service amount with sorting ability

TDR Transaction Data Record
Listing of detailed data records of MAP service includes fields as below

  • beginning time
  • calling GT (include SSN)
  • called GT (include SSN)
  • result (Ended, Going, Error, Reject, Abort, UDTS)
  • duration
  • IMSI number
  • MSISDN number
  • MAP message sequence
  • MAP operation code
  • MAP error code

Operators can search those records interested by its any field.
By flexible configuration, operator can launch analysis for the mentioned below.

1> service between two subscribers by GT (SSN)
2> transaction trace for subscribers by IMSI and MSISDN number
3> trace analysis for error reason
4> specific MAP service
5> ultra-short or ultra-long operation

Base Station Network optimization
QSZ-225 provides A&A-bis based test and wireless network optimization.

  • switch and update: providing detailed data for switch and update operation of base cell interested, including switching (in/out/all) count, switching success rate, switching failure rate, switch request, switch fault, switching cleanup, switch rejection, location update count, registering count and failure reason.
    The tester also provides detailed statistics for failed reason to shoot existing troubles.
  • A interface circuit: analysis and trouble-shooting of :
    • Call drop
    • PCM and CIC fault
    • Holding duration
    • Fault rejection
    • Reason of cleaning up request
    • Disconnection
  • wireless coverage: for cell radio coverage and interference problem.
    Abs message statistics provides detailed message statistics on LAPD, RSL, and DTAP layer of Abis interface. Wireless isolated island will be located by analysis of relations etween service quality level and distance from various BTS and intuitionist graphical result is for easy understanding. Relation of service quality level and Rx power level clarifies Abis coverage & interference situation.
  • A interface process record: start time, process type, LAC : Cl of BS, process result, duration and BSSMAP sequence included.

GPRS Service Analysis
QSZ-225 supports GPRS integration test. It collects data at Gb, Gi, Gn and Gp interfaces and makes deep analysis of QoS and subscriber service.

  • wireless network optimization: based on Abis and Gb data, probing problem of wireless quality of GPRS through analysis on information from measurement report of mobile.
  • backbone network service: focusing on datacom service of GPRS by testing Gn, Gi and Gp. It provides protocol analysis and service statistics of IP package, provides GSN traffic monitoring and verifying processing ability of backbone network by traffic simulation.
  • service signaling flow: tracing GRPS data service process by online test at Gb and Gn interface. Operation can obatin hole signaling flow and data exchange flow in a separated window for each GPRS data session. All messages and packages can be decoded by their own sequence.
  • GPRS QoS: including upstream/downstream message traffic, responding delay of different interfaces, jitter, package loss and call drop.
  • subsriber service: subscribers amount, subsribers region distribution, application traffic and download rate etc. With authorization, operator even can check the application data contents for information monitoring.

IN Service Survey
QSZ225 supplies applications for INAP and CAP (WIN) service assurance. Service records of all IN service process, composed of start time, calling number, called number, process result, call duration, IMSI, BCSM event type, BCSM event reason, calling GT (including SSN), called GT (including SSN), WIN code, WIN error code, MIN, MDN, are also provided and detailed signaling flow can be gotten. Real-time CAP call trace for specified error reason, IMSI, calling number and called number help operator solve network service maintenance trouble.

Subscriber-based analysis provides searching and sorting for subscriber featured by vast call amount or high bill amount or high failure ocurrence so that operators can put more attention on these key subscribers and take pertinent solution to preserve network resource.

CAP operation performance including their respective success rate, failure rate and error distribution can be reported. Network processing power can be measured by Call Attempt Per Second (CAPS) for SCP.

CDMA Data Service Test
Real-time monitor of R-P interface: R-P interface is access interface from wireless network to package core network in CDMA20001X, where both signaling message and user data pass. Real-time monitor of R-P interface is used to master data traffice and data speed to help operator observe network condition.

PPP link analysis includes :

  • connection monitoring
  • connection process fetching
  • link status analysis
  • link abnormal status analysis
  • traffic analysis
  • performance cognizance

Radius AAA analysis includes :

  • Authentication request sum, success amount and ratio
  • Authentication failure reason
  • Billing request sum, success amount and ration, billing exception reason

CDMA2000 core network performance analysis includes :

  • core network protocol decoding including RADIUS, MIP etc
  • traffic monitoring of PDS an HA
  • traffic simulation

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  • Completely supporting 2G/2.5G network test
  • Distinct testing logic, easy operation and three mouse clicks fulfill statistics for finding trouble, process test for analyzing trouble and decoding for locating trouble.
  • Strong data filtering & catching; tracing specified message or process
  • Supporting multi-interface signaling interaction for straight trouble shooting.
  • High resistance isolator allowing longer test cable (> 100M) and non-intrusive test
  • Designed from customer view for more praticable application

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Layer Compliance Standard Layer Compliance Standard
MTP ITU-TQ.700-710 MAP GSM09.02 V7.7.0
TUP ITU-TQ.721-725 PP SMS GSM04.11 V7.0.0
ISUP ITU-TQ.761-767 LSC GSM04.80 V7.1.0
SCCP ITU-TQ.711-716 CAP GSM09.78.V7.0.0
TCAP ITU-TQ.771-774 BSSMAP GSM08.08 V8.0.1
INAP ITU-TQ.1218, X.208,X.209 DTAP GSM04.08 V7.4.2
T1TCAP ANSI T1.T114 ABIS L2 GSM08.56 V7.0.0
  ABIS L3 GSM08.58 V8.0.0
Layer Compliance Standard Layer Compliance Standard
NS GSM08.16 V7.1.0 PP SMS TIA/EIA IS 637
BSSGP GSM08.18 V7.0.0 LSC TIA/EIA IS 664
LLC GSM04.64 V8.0.0 WIN TIA/EIA IS 771
SNDCP GSM04.65 V6.4.0 WIN (PPC) TIA/EIA IS 826
GMM/SM GSM04.08 V7.4.2 BSSAP TIA/EIA IS 634 , IOS2.4, IOS 4.0
GTP GSM09.60 V7.4.1 A3 / A7 IOS4.X, IOS3.X, IS-634
GTP´ GSM12.15 V7.2.1 WIP TIA/EIA IS 835,3GPP2P.S0001-A
BSSAP+ GSM09.18 V8.0.0 A10 / A11 IOS4.X
RLC/MAC GSM04.60 V PPP RFC 1661 / 1662 / 1962 / 1974 / 1979 / 1994
  IP RFC 1438 / 1577
UDP / TCP RFC 793 / 768
MIP RFC 2002 / 2003 / 2004 / 2005 / 2006 RFC 2344
Layer Compliance Standard
Radius RFC 2138, RFC 2139
MAC IEEE 802.3
Routing Protocol RIP, OSPF, GBP
Application Protocol HTTP, POP3, FTP, TELNET

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  • bit Rate: 2048kbit/s + 50ppm
  • input Code: HDB3
  • Ethernet interface: 10/100M
  • input loss: <6dB
  • time precision: 100ns
  • jitter margin:>1.5UI (20Hz-2.4kHz)
  • echo loss:> 18dB (120KHz02048MHz)
  • linear Attenuation: 38dB
  • cable attenuation Compendation: 6dB
  • reliability: MTBF > 20000hr
  • power: AC 220V ± 10%, 48Hz-66Hz
  • input impedance: 120ohm, 75ohm
  • working temperature: -10ºC ~ +45ºC
  • storage temperature: -20ºC ~ +70ºC
  • relative Humidity: 20%-80%

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