Abstract: A VPN service management system enabling a customer to rapidly and easily change a VPN service condition, that is, a VPN service management system for managing a VPN service for a communication network provided with a customer network and a provider network and having a VPN service manager for managing a VPN service for a provider network and a VPN service agent for managing a VPN service for a customer network. The VPN service manager changes the VPN service condition in real time in accordance with an operation status of the customer network in cooperation with the VPN service agent.

Abstract: A control apparatus with a window control function including a distance computation unit for computing a signed n-bit distance as a result of subtraction of a second sequence number cyclically updated to vary like a modulo-N number from a first sequence number also cyclically updated to vary like a modulo-N number where N is a positive integer greater than 1 and the nth power of 2 is greater than N(2n>N), and a lowest-order-bit extraction unit for extracting m lowest-order bits of the distance where the mth power of 2 is equal to N(2m=N). The control apparatus further includes a distance judgment unit for forming a judgment as to whether or not the first sequence number is within a window set with the second sequence number used as a reference by comparison of the m lowest-order bits of the distance extracted by the lowest-order-bit extraction means with a size of the window.

Abstract: Disclosed is a mobile communication system that includes a mobile switching center having a multiprocessor configuration and radio base stations subordinate to the mobile switching center, with a single radio base station being connected with mutually independent signaling links from a plurality of processors within the mobile switching center. When a call issued from that or other system is received by a subscriber under that system, call ID information contained in a mobile call demand signal sent from the mobile switching center to the radio base station has a storage area for an identifier of a processor within that mobile switching center. The radio base station allows the destination of return of a mobile call response signal to be the processor indicated by the processor identifier.

Abstract: A VPN service management system enabling a customer to rapidly and easily change a VPN service condition, that is, a VPN service management system for managing a VPN service for a communication network provided with a customer network and a provider network and having a VPN service manager for managing a VPN service for a provider network and a VPN service agent for managing a VPN service for a customer network. The VPN service manager changes the VPN service condition in real time in accordance with an operation status of the customer network in cooperation with the VPN service agent.