Telecommunication Solutions
Impossible Just Takes Longer to Design

Local Number for Visitors


  • Connects to operator’s switching equipment using SS7/ISUP and SS7/MAP over E1 for serving inbound roamers;
  • Voice traffic is served on the Loop Around principle, meaning that only ISUP signalling traffic is passed through the server;
  • Incoming and outgoing voice channels are connected semi-permanently in advance;
  • Connects to the operator’s SMSC using SMPP v3.4;
  • If any of the subsystems reaches a set performance threshold, additional modules are brought into service;
  • SNMP management alarms and E-mail/SMPP alarm notification;
  • Powerful logging system (CDR generation);
  • Dynamic system configuration.

Service provision

The operator sets aside a range of numbers to provide guest subscribers with a local MSISDN number. After registering in the operator’s network, the roamer orders the service by sending an SMS to a specified local number. The SMS is routed to the LNFV server, which assigns a number from the pre-defined range and attaches the subscriber’s IMSI to the temporary MSISDN number. The subscriber receives his new local number by SMS.

Subsequently, all calls made to that number are routed by GMSC to the Local Number server using ISUP. The operator’s exchange equipment handles the redirection of calls to the server.

The LNFV server checks the subscriber’s location and his current MSRN, and then routes the call to the subscriber. Voice calls are switched on the Loop Around principle.

The temporary number can be freed up when the subscriber ceases to be registered in the network, or if he sends an SMS to cancel the service (in a similar manner to the process of subscribing to the service).

The system maintains CDR logs, in which the following parameters are recorded:

  • Subscriber A’s number
  • Subscriber B’s number
  • Subscriber B’s number type
  • Subscriber B’s IMSI
  • Subscriber B’s VLR
  • Activity (incoming call/SMS)

Subscription generation

For a new subscription, all the subscriber has to do is send an SMS to a special service number or call the operators service center.

Subscription cancellation

The subscriber can cancel subscription to the service by sending an SMS to the service number. Similarly, subscriptions can be cancelled automatically after the subscriber has been inactive for a period of time set by the operator.

PROTEI LNV offers a wide range of options for collecting statistics and generating CDRs

Unified maintenance system

System maintenance can be carried out in a variety of ways: Telnet/SSH, FTP, web GUI and command line interface.