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LawfulInterceptionVoiceRecorder

CONTENTS:

• Stillink 3200 Lawful Interception Recorder in Brief
• Reliability, Duplication and Redundancy
  • Firmware and Processing
  • Power System
  • System Resources
  • HI3 (E1) and Ethernet Interfaces
  • Reference Models
    • Single Recorder, Single FTP
    • Single Recorder, Dual FTPs
    • Dual Recorders, Dedicated Single FTP
    • Dual Recorders, Dedicated Dual FTPs
• Technical Specifications
• Physical Connections
• Programming
  • Set the Signaling Type as SS7 ISUP
  • Enable Voice Recording
  • Make Virtual Routing
  • Adjust FTP Parameters
  • Set File Name Format for Voice Records
• Verifying SS7 Communication / Signaling

STILLINK 3200 LAWFUL INTERCEPTION RECORDER IN BRIEF

SS7 has been playing a principal role in controlling the signaling in intelligent networks. This standard has been deployed globally for intelligent networks in wireline and/or wireless environments. SS7 offers an alternative source of intelligence collection.

Telesis Stillink 3200 LIR is a voice recorder element in monitoring center of LEAs. The applied solution is according to European (ETSI) standards for LI. LEAs ,using various network elements of multi-vendors, may consider Stillink 3200 LIR.

Some hallmarks of the solution are:

• Cost-effective for either TSPs or government LEAs
• Robust, reliable hardware and firmware
• Telesis proprietary firmware (Xymphony tailored for lawful interception recording)
• High MTBF values
• Web based, easy management and provisioning
• E1 physical interfaces to connect MD (mediation devices) for recording
• Scalability. Up to 16 E1s, 480 channel recording capacity in a single system
• SS7 ISUP signaling on E1s
• Flexible parameter adjustment for SS7 like point codes, CIC
• Up to 16 E1 SS7 link sets (1 to 16, programmable)
• The interface model: handover interface HI3 (CC - Content of Communication)
• Monitored and recorded HI3: unidirectional
• Use of subaddress and UUS for interception related information
• Voice (Content of Communication) recorded transparently without any compression (64kbps, wav files)
• Using FTP, the recorded data from the Stillink 3200 is automatically exported to a file server in advance
• With support of dual FTP servers (primary and secondary), file transfer is warranted
• Voice records buffering capability in case both FTP servers fail
• Flexible file naming of intercepted voice records before exporting to FTP servers
• Auto selection of directories in FTP server before export (related to intercept information)
• SNMP alarm traps for E1 status
• Generating performance metrics, statistics, and records

Information, which may be used in file naming of intercepted voice records are:

• Any alphanumeric separator
• Recording start date
• Recording start time
• Recording end date
• Recording end time
• Calling number
• Called number
• B channel number
• Domain identifier
• Lawful interception identifier
• Communication identity number
• Call identity number
• CC link identifier
• Operator identifier
• Network element identifier
• Direction indication
• TMR (Transmission Medium Requirement)
• High layer capability
• Mobile bearer service code
• Mobile teleservice code
• Any fixed alphanumeric character set in any location

All or some of the above information may be used in file name in any sequence. Consequently, TSPs or LEAs may program their desired file naming description easily.

RELIABILITY, DUPLICATION AND REDUNDANCY

The hardware and firmware of the Stillink 3200 LIR are reliable and fault tolerant solution for no loss of valuable intercept data. In addition, higher levels of system availability can be achieved via external redundancy and duplication as mentioned in reference models.

FIRMWARE AND PROCESSING

The advanced design of the Stillink 3200 LIR incorporates state-of-the-art Industrial CPU and Digital Signal Processors that are capable of executing hundreds of millions of instructions a second. Highly efficient use of the system`s processing power, with the help of intelligent algorithms, leaves no possibility that an overload condition will arise. In the operation of the Stillink 3200 LIR, there is a sufficient margin for overload situations. Improved speed, security, and reliability are guaranteed by the placement of the generic programs and operating parameters in non-volatile semiconductor memory elements. The Stillink 3200 LIR incorporates processing units that take full advantage of the massive amount of computing power that is now available, along with the myriad of software development tools.

The Stillink 3200 LIR is a Stored-Program-Controlled (SPC) system. Its leading-edge operational software, Xymphony, has been developed by Telesis A.S. specifically for this system. With many programmable features, Xymphony makes the lawful interception recording highly efficient. Xymphony within the Stillink 3200 LIR is well structured and is developed by a high level language of C. Xymphony software provides strategies to prevent the occurrence of programming errors to escalate to present sufficient information for quick solving of the errors. The Stillink 3200 verifies the integrity of its software at regular basis.

POWER SYSTEM

By default, the Stillink 3200 LIR has a single solid state, high quality, robust (with high MTBF value), convectional cooling (without mechanical fans), field-proven power system. Hallmarks of this power system are:

• Built-in active PFC function
• Short circuit / Overload / Over voltage protections
• Cooling by free air convection
• 100% full load burn-in tested
• Fixed switching frequency at PFC:67KHz PWM:134KHz
• Overload protection: Constant current limiting, recovers automatically after fault condition is removed
• Overvoltage protection: Shut down o/p voltage, re-power on to recover
• MTBF 224300 hours MIL-HDBK -217F (25 )

SYSTEM RESOURCES

Although some of the Stillink 3200 LIR`s common control function is implemented in a centralized manner, many resources like digital signal processors (DSPs) are distributed. Digital signal processors provide HDLC for E1 interfaces. DSP distribution provides redundancy. All available channels from all DSPs are collected in a common pool, which is ready to serve any request within the system. In other words, in case of a failure in a DSP, its functions can be handled with other DSPs in this distributed system. The expense in this method may be concurrent call recording capacity.

HI3 (E1) AND ETHERNET INTERFACES

External synchronization sourcing is programmable and multiple HI3 E1 interfaces may be candidates for sourcing. Intelligent algorithms within the Stillink 3200 LIR select the source among the available HI3 E1 interfaces. Consequently, loss of signal in an E1 interface does not necessarily cause the loss of synchronization. The Stillink 3200 LIR has multiple ethernet interfaces. The Stillink 3200 LIR continuously monitors ethernet interfaces for faults and warnings.

REFERENCE MODELS

Different levels of system availability can be achieved via redundancy, from duplicated FTP servers to fully redundant Stillink 3200 LIR systems and FTP servers.

TECHNICAL SPECIFICATIONS

PHYSICAL CONNECTION

HI3 E1 interface on the Stillink 3200 LI Recorder is receive only. This being the case, it is sufficient to have single pair of wires from mediation device to the Stillink 3200 E1 interface.

HI3 interfaces on Stillink 3200 can connect to 120 ohm balanced terminations. The clock of a Stillink 3200 should be programmed to synchronize with any of the E1 interfaces. The line code is programmable as AMI or HDB3. Cyclic redundancy check (CRC4) can be enabled or disabled for each E1 interface individually.

PROGRAMMING

1. SET THE SIGNALING TYPE AS SS7 ISUP

Although licenses may have been installed at the factory, Stillink 3200 LI Recorders are not pre-configured at the factory for signaling. With some simple programming, signaling type of an E1 can be selected as SS7.

Selecting another signaling or protocol type for an E1 interface is easy. In Common properties page, Change interface type is used for changing the interface type. Select E1 ITUT SS no:7 ISUP signaling from the pulldown menu and press Apply button next to the right. After the page refreshes, set Line signalling to Non-Std as shown below.

Be aware that setting the signaling type is not the last step for programming an E1 interface.

Do not forget: Whenever OK button is clicked in Common properties pages, the modified parameters are sent to the operational memories of the Stillink 3200 LI recorder. The operational memories are RAMs, so that, they can be lost if the Stillink 3200 is powered down. In order to store these programmed parameters to the nonvolatile memories of the system, Save command in Homepage should be operated. There, click on OK button to store programmed parameters to the nonvolatile memories.

After setting the signaling type to E1 ITUT SS no:7 ISUP, in the same Common properties page, adjust Destination point code DPC, Originating point code OPC, and Circuit identification code prefix values according to connected HI3 interface with provisioning.

2. ENABLE VOICE RECORDING

In Common properties page, mark Voice recorded for all calls checkbox marked.

3. MAKE VIRTUAL ROUTING

In Common properties page, select a Routing criteria table and click on Edit button.

In selected (or assigned) Routing criteria table table, for all Prefixes (0 to 9), set Min and Max fields to 1. Set the Law action as Test tone. Keep Authorizations as 1.

4. ADJUST FTP PARAMETERS

In homepage, Ethernet paragraph, click on Voicerecorder link. The following page opens.

Set the access authorization parameters for the primary and secondary (if available) FTP servers, where voice records to be exported.

5. SET FILE NAME FORMAT FOR VOICE RECORDS

The Stillink 3200 LIR is capable of flexible file naming of intercepted voice records before exporting to FTP servers. File name format can be designed in Voicerecorder page.

File name may include up to 32 fields in any combination or sequence. These are; Recording start date, Recording start time, Recording end date, Recording end time, Calling number, Called number, B channel number, Domain identifier, Lawful interception identifier, CC link identifier, Communication identity number, Call identity number, Operator identifier, Network element identifier, Direction indication, Transmission Medium Requirement, High layer capability, Mobile bearer service code, Mobile teleservice code, and Any fixed alphanumeric character set in any location.

Furthermore, the first location Sub Directory allows to export voice records to predefined directories onto FTP server.

Marking a field and clicking on Edit button opens File name field page with a pulldown menu for the selection.

VERIFYING SS7 COMMUNICATION / SIGNALING

Thanks to the advanced signaling analyzer embedded into the Stillink 3200 LI Recorder, it is possible to monitor or analyze the signaling (protocol) on a selected E1 interface without requiring any additional and costly external analyzer. The signaling (protocol) analyzer is capable of analyzing various events and signaling layers. After programming the signaling parameters, and establishing a physical connection, the analyzer may be utilized to verify the communication.

To monitor a selected E1 interface, you may use the freeware Telesis XTools Utility.