SOSM. System of Operative-Search Measures

SOSM system developed for providing legal information monitoring for operative-search possibility in the fixed and mobile networks. Protei Ltd specialists develop protocol-tester SOSM and SOSM-analyzer for technical support of the national legislation requirement.


TOR-4Protocol-Tester TOR-4

The protocol-tester TOR-4 is integrated testing equipment for SOSM interface in switching nodes and exchanges of Russian PSTN.

The system presents intelligent simulator of SOSM CP (Control Point), equipped by monitoring facilities for voice and control channels of the SOSM interface, possibilities for creating and starting scenarios and load generating. The SOSM protocol-tester TOR-4 provides complex testing of SOSM facilities realized in an international exchange, exchange or PABX under testing.

The system is designed in accordance with requirements of the documents of the last versions, which regulate protocol parameters and functioning algorithm for SOSM equipment at PSTN of the Russian Federation:

  1. Technical requirements or the information interchange channels between SOSM and CP for electronic exchanges;
  2. Technical requirements or the information interchange channels between
    SOSM and CP for mobile networks;
  3. Standards of G.703, X.25, V.24 series;



  • Command generation;
  • SOSM response monitoring;
  • X.25 packages monitoring in two channels;
  • Subscribers status monitoring;
  • Statistic collection for events in the system (X.25 operating, SOSM functioning);
  • Displaying statistical information in user comfortable form;
  • Support till 8 E1;
  • Voice channels monitoring;
  • Recording of all voice information, coming through voice channels;
  • Scenario implementation possibility;
  • The work results keeping;
  • Protocol-tester TOR-4 can be used at the stage of SOSM equipment development in electronic exchanges, during their certificate, factoryand field tests.


Structure scheme

The protocol-tester TOR-4 as a simulator of SOSM CP (Control Point) can be connected to the testing station through E1 trunk (through 30 and 31 time slots).

For transmitting information by command channels and data using X.25 protocol (according to the document "Technical terms and conditions to the information interchange links between SOSM and CP").

Software and hardware parts of the protocol-tester according to the functionality can be divided into two modules: Sonde and Terminal.

Sonde module providing physical jointand SOSM interface network level. Terminal Module response for control of the system and providing user interface of cooperation with SOSM module.


Technical characteristics of the Terminal and Sonde:

Processor: Celeron

Intel Celeron, 1 GHz and faster

Hard Disk:

40 Gb or more

Operative memory:

128 Mb or more

Error-free running time:

5000 hours


Versions of exploitation:

  • Fixed network
  • MRS network
  • Trunking networks


Complete set delivery:

  • PC with installed operating systems Windows XP and Linux
  • Interface card E1
  • Connection cable for E1
  • Garniture for voice channels monitoring
  • Documentation




Encyclopedia on SOSM and X.25 protocol

The base of consulting documents is a set of documents intended to inform telecommunication personnel about specified signaling protocols, their testing and converting.

The base also includes: regulating PSTN documents, information on exchanges, which support corresponding signaling protocols, and additional literature list.

System requirements:

The base is realized at CD. The documents are made in PDF format (Portable Document Format).


Engineering aspects of SOSM

GENERAL TECHNICAL REQUIREMENTS to SOSM function facilities at trunking mobile radiotelephony systems (SOSM – TMRS)

TECHNICAL REQUIREMENTS to SOSM function facilities at mobile radiotelephony networks (SOSM – MRS)

TECHNICAL REQUIREMENTS to SOSM function facilities at public paging networks (PPN SOSM)

Set of control and testing equipment “protocol-tester TOR” Operation manual (User guide for protocol-tester TOR)

XSM. Converter of SOSM interface

Technical terms and conditions to the information interchange links between TSNC and XSM





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