Abstract: In a VoIP communication apparatus which receives a call number from one telephone device and judges whether the call number coincides with any of plural telephone numbers managed by a call server, a symbol storing section which stores respective symbol correspondence data formed by writing a distinguishable predetermined bit value into different predetermined bit positions corresponding to respective symbols used for expressing the telephone number; a number scope storing section which stores respective figure correspondence data each formed by writing the predetermined bit value into at least one the same predetermined bit position corresponding to more than one usable symbol on corresponding figure; and a collating and judging section which respectively collates the symbol correspondence data corresponding to the symbols on respective figures in the call number with the figure correspondence data of the same figure and judges whether the call number is contained in these telephone numbers are provided.

Abstract: In a VoIP communication apparatus which receives a call number from one telephone device and judges whether the call number coincides with any of plural telephone numbers managed by a call server, a symbol storing section which stores respective symbol correspondence data formed by writing a distinguishable predetermined bit value into different predetermined bit positions corresponding to respective symbols used for expressing the telephone number; a number scope storing section which stores respective figure correspondence data each formed by writing the predetermined bit value into at least one the same predetermined bit position corresponding to more than one usable symbol on corresponding figure; and a collating and judging section which respectively collates the symbol correspondence data corresponding to the symbols on respective figures in the call number with the figure correspondence data of the same figure and judges whether the call number is contained in these telephone numbers are provided.

Abstract: Telecommunication is exchanged between first telecommunication equipment and second telecommunication equipment. A response monitoring packet is sent from the first telecommunication equipment towards the second telecommunication equipment during telecommunication exchange. A timer is activated in the first telecommunication equipment and a response packet is received from the second telecommunication equipment during telecommunication exchange. A response time, defined as a time length from a time at which the response monitoring packet is sent and a time at which the response packet is received, is calculated. The response time is compared to a threshold value, which is defined corresponding to a specific communication class. A telecommunication line connecting the first telecommunication equipment and the second telecommunication equipment is disconnected if the response time is in excess of the threshold value.

Abstract: To provide a network control system which prevents a system performance degradation caused by generating/updating routing information and enables a connection request to be established reliably. The significant change detection module 33 sets the flag 33a to on when a pre-determined change occurs. The first timer 21 determines the longest interval at which the routing information 24 is updated, while the second timer 22 determines the shortest interval at which the routing information 24 is updated. When the first timer 21 times out, the routing information update control module 23 unconditionally updates the routing information 24. When the second timer 22 times out, the routing information update control module 23 updates the routing information 24 only if the flag 33a is on.